- Email: [email protected]
Iris-claw intraocular lens for aphakia: Can location influence the final outcomes?
818
ARTICLE
Iris-claw intraocular lens for aphakia: Can location influence the final outcomes? Rosario Touri~ no Peralba, MD, PhD, David Lamas-Francis, MD, Teresa Sarandeses-Diez, MD, Laura Martínez-Perez, MD, PhD, Teresa Rodríguez-Ares, MD, PhD
Purpose: To describe the demographic data, evaluate the longterm refractive and anatomical outcomes, and report the incidence of complications of anterior iris (prepupillary) and posterior iris (retropupillary) fixation of the Artisan aphakia iris-claw intraocular lens (IOL).
Setting: Complejo Hospitalario Universitario de Santiago de Compostela, Spain. Design: Retrospective case series. Methods: Patients who had iris-claw IOL implantation were
had retropupillary implantation. Indications for surgery were IOL luxation or subluxation (n Z 24), lens luxation or subluxation (n Z 17), trauma (n Z 15), aphakia (n Z 30), and other (n Z 9). The CDVA improved significantly in both groups and there were no differences between them. A significant ECC reduction was observed in both groups, with no differences between them. The incidence of CME was 16.1% (21.8% in the prepupillary group and 7.9% in the retropupillary group at 3 months and 8 months, respectively), although the difference was not statistically significant. Other postoperative complications were rare and no differences were found between groups.
divided into 2 groups: Group 1 (prepupillary) and Group 2 (retropupillary). The corrected distance visual acuity (CDVA), anatomical changes, endothelial cell count (ECC), presence of cystoid macular edema (CME), and operative and postoperative complications were determined.
Conclusions: Irrespective of location, the iris-claw IOL provided good visual outcomes with few complications. However, prepupillary IOL implantation seemed to contribute to greater endothelial cell loss and earlier onset of CME.
Results: The study comprised 95 eyes of 95 patients. Fiftyseven patients had prepupillary implantation and 38 patients
J Cataract Refract Surg 2018; 44:818–826 Q 2018 ASCRS and ESCRS
I
ntracapsular intraocular lens (IOL) implantation remains the ideal procedure after cataract extraction. However, alternative methods of IOL implantation should be considered in some cases, such as capsular rupture and significant zonular dehiscence during cataract surgery, as well as weakened zonular fibers because of trauma, pseudoexfoliation syndrome, pathological myopia, uveitis, or hypermature cataracts, or because of Marfan syndrome or Weill-Marchesani syndrome. Surgeons might choose to implant an anterior chamber IOL (AC IOL) (also known as angle-supported IOL) or a scleral-fixated IOL. However, neither of these procedures are exempt from complications. Use of AC IOLs might lead to reduced endothelial cell count (ECC) and corneal
decompensation, secondary glaucoma, and chronic inflammation. Scleral-fixated posterior chamber IOLs (PC IOLs) might also cause inflammation, retinal tears, choroidal hematoma, and cystoid macular edema (CME). Iris-claw IOLs were designed by Jan Worst in 19781 to correct aphakia after intracapsular cataract surgery. The Artisan aphakia 205 IOLA (Ophtec BV) is a 1-piece biconvex, made of poly(methyl methacrylate), 8.5 mm long (7.5 mm for pediatric patients), and it has an optic zone of 5.0 mm. This IOL was originally designed to be placed over the anterior surface of the iris. The haptics are fixed to an avascular portion of the iris without sutures. The IOL can be easily centered and it does not come into contact with the anterior chamber angle.1 Several studies
Submitted: November 4, 2017 | Final revision submitted: April 15, 2018 | Accepted: May 4, 2018 ~o Peralba, Lamas-Francis, Sarandeses-Diez, Martínez-Pe rez, Rodríguez-Ares), Ophthalmology Department, Complejo From the Cornea and Ocular Surface Unit (Tourin ~o Peralba, Rodríguez-Ares), Medical School, Santiago de Compostela Hospitalario Universitario de Santiago de Compostela and the Surgery Department (Tourin University, Santiago de Compostela, Spain. Presented at the XXXV Congress of the European Society of Cataract and Refractive Surgeons, Lisbon, Portugal, October 2017. Francisco Gude Sampedro, MD, PhD, Clinical Epidemiology Unit, University Hospital of Santiago de Compostela, revised the statistics for this paper and provided technical advice. ~o Peralba, MD, PhD, Cornea and Ocular Surface Unit, Ophthalmology Department, Complejo Hospitalario Universitario de Santiago Corresponding author: Rosario Tourin n Baltar s/n CP 15706, Santiago de Compostela (A Corun ~a), Spain. Email: [email protected]. a Ramo de Compostela, Ru Q 2018 ASCRS and ESCRS Published by Elsevier Inc.
0886-3350/$ - see frontmatter https://doi.org/10.1016/j.jcrs.2018.05.010
TWO LOCATIONS FOR IRIS-CLAW IOL IMPLANTATION
have reported on the safety and effectiveness of this IOL in both positions: anterior chamber (prepupillary) and posterior chamber (retropupillary).2–4 This study aimed to analyze the viability and safety of Artisan iris-claw IOL implantation in the absence of capsular support, as well as to determine whether anterior iris (prepupillary) or posterior iris (retropupillary) location influence the final visual and anatomical results. PATIENTS AND METHODS This retrospective cohort study included patients who had irisclaw IOL implantation consecutively between 2006 and 2016 at the University Hospital in Santiago de Compostela, Spain. All patients were previously informed about the procedure and its risks and signed a specific informed consent form before implantation. This study was conducted in accordance with the tenets of the Declaration of Helsinki and approved by the Galician research ethics committee (registration code 2017/127). The inclusion criteria were as follows: subluxation of preexisting IOL (degrees 1, 2, and 3), lens subluxation (pseudoexfoliation syndrome, Marfan syndrome, lens coloboma, and other pathologies), trauma and aphakia without capsular support. All patients presented with an iris morphology that allowed a stable IOL placement. The exclusion criteria were as follows: iris abnormalities hampering enclavation (mydriasis O5.0 mm or absence of iris), history of ocular inflammation in the previous 6 months, uncontrolled intraocular pressure (IOP), severe corneal opacity, and poor visual prognosis. All procedures were performed by the same anterior segment surgeon (R.T.). Iris-claw IOL implantation was carried out as a primary or secondary procedure. The patients were divided into 2 groups: Group 1, anterior chamber (prepupillary) implantations (Figure 1) and Group 2, posterior chamber (retropupillary) implantations (Figure 2). The surgeon identified the best location in each case (prepupillary or retropupillary), according to anterior chamber depth, ECC, presence of glaucoma (especially pigmentary glaucoma), and anatomical complexity. The IOL was always retropupillary when the anterior chamber was less than 3.0 mm, the ECC was less than 1200 cells/mm2, or in the presence of pigmentary glaucoma or advanced glaucoma. Surgical Technique Anesthesia was peribulbar or topical depending on the patient’s requirements and the surgeon’s preference. The A-constant used
Figure 1. Iris-claw intraocular lens to correct the aphakia in absence of capsular support. Anterior iris surface fixation (prepupillary location).
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was 115.0 (prepupillary) and 116.8 (retropupillary). A superior clear corneal incision was made for both locations (prepupillary and retropupillary). It is important to immobilize the IOL correctly with special forceps (Shepard forceps). Prepupillary IOLs were stabilized with these forceps at the optics and the midperipheral iris was fixated to the haptics with a needle inserted through the paracenteses (10 o’clock and 2 o’clock). Retropupillary IOLs were pushed behind the iris, 1 haptic after the other. It is important to grasp a large part of the body of the IOL with the Shepard forceps to prevent its displacement, especially when enclavating the midperipheral iris into the haptics. A reverse Sinskey hook or a 27-gauge needle bent 45 degrees was passed through the paracenteses (3 o’clock and 9 o’clock) to enclavate a sufficient portion of iridal tissue. The ideal interlocking of the iris-claw IOL was considered correct when dimples were visible on the iris. This helps prevent spontaneous detachment of the IOL into the vitreous cavity. The corneal wound was sutured with 10-0 nylon suture and selectively removed after 8 weeks, depending on the patient’s refractive and topographical astigmatism. Steroid and antibiotic eyedrops were prescribed for 1 month. Data Collection Demographic, clinical, and surgical characteristics were obtained retrospectively from medical records. The demographic data analyzed included age, sex, eye operated, etiology of aphakia, and preoperative eye pathology. The following clinical parameters were collected preoperatively and at 1, 3, and 6 months and annual visits postoperatively: The corrected distance visual acuity (CDVA) registered with a logarithm of the minimum angle of resolution chart in Early Treatment Diabetic Retinopathy Study (ETDRS) letters. Corneal astigmatism was measured using the Scheimpflug system (Pentacam, Oculus Optikger€ate GmbH). Postoperative corneal astigmatism was recorded when it remained stable after suture removal. Slitlamp evaluation: anatomical changes on the iris related to IOL implantation (pupil deformity and atrophy at the haptic enclavation site). Intraocular pressure measured with the Perkins applanation tonometer. Intraocular hypertension was defined as IOP of 22.0 mm Hg or higher and hypotony as 6.0 mm Hg or lower. The ECC was obtained using specular microscopy (Ophthaltec, Costruzione Strumenti Oftalmici). The macular evaluation with optical coherence tomography (OCT) (Cirrus 500, Carl Zeiss Meditec AG) determined the presence of edema.
Figure 2. Iris-claw intraocular lens with posterior iris surface fixation (retropupillary location).
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Surgical data included the following: primary or secondary IOL implantation, location (prepupillary or retropupillary), position (horizontal, vertical, or oblique), operative and postoperative complications (ECC decrease, CME, etc.). Statistical Analysis The Kolmogorov-Smirnov test with Lilliefors correction was used to determine whether the continuous variables were normally distributed. The mean G SD values or median values and interquartile ranges (IQRs) are presented. Categorical variables are given as numbers and percentages. Chi-square, Student t test, and Mann-Whitney U test were used to compare the groups. Differences were considered statistically significant at a P value less than 0.05. All analyses were conducted using SPSS software (version 19.0, IBM Corp.) and R (version V3.1.2, R Foundation for Statistical Computing).
RESULTS Descriptive Results
The study comprised 95 eyes of 95 patients (43 women [45.3%], 52 men [54.7%]). Table 1 shows the demographic characteristics of the study patients. There were 48 right eyes (50.5%) and 47 left eyes (49.5%). Fifty-seven patients (60.0%) received a prepupillary IOL and 38 patients (40.0%) received a retropupillary IOL. The median age at the time of surgery was 67 years (IQR Z 21). The patients were followed between 1 month and 6 years (median 12 months, IQR Z 18). There was no statistically significant difference in preoperative ocular pathology between the groups. Table 2 shows the most frequent conditions. The most common indications for IOL implantation were surgical aphakia (n Z 30) and IOL subluxation (n Z 24). Table 3 shows the indications for surgery. Intraocular lens implantation was performed as a primary procedure in 56 patients (58.9%) (36 prepupillary, 20 retropupillary) and as a secondary procedure in 39 patients (41.1%) (21 prepupillary, 18 retropupillary). The iris-claw IOL was placed in a horizontal position in 90 eyes (94.7%), an oblique position in 4 eyes (4.2%), or a vertical position in 1 eye (1.1%).
letters (IQR Z 28) before surgery and 75 ETDRS letters (IQR Z 18) after surgery. This improvement was statistically significant. The mean gain was 6.1 G 27.5 letters. After surgery, the CDVA was higher in 20 patients (58.8%), remained the same in 2 patients (5.9%), and was lower in 12 patients (35.3%). In the retropupillary group, the median CDVA was 50 ETDRS letters (IQR Z 48.5) before surgery and 65 ETDRS letters (IQR Z 42.0) after surgery. This improvement was also statistically significant. The mean gain was 11.5 G 27.1 letters. After surgery, the CDVA was higher in 17 patients (60.7%), remained the same in 3 patients (10.7%), and was lower in 8 patients (28.6%). However, there were no statistically significant differences in CDVA improvement between Groups 1 and 2 (Figure 3). The mean difference was 5.4 ETDRS letters (95% confidence interval [CI], 8.5 to 19.3). The median topographic astigmatism was 1.3 diopters (D) (IQR Z 3.0) before surgery and 1.9 D (IQR Z 2.2) (not statistically significant). In the prepupillary group, these results were 1.5 D (IQR Z 5.1) and 1.95 D (IQR Z 2.5), respectively; and 1.3 D (IQR Z 2.7) and 1.8 D (IQR Z 2.1) in the retropupillary group. Preoperative and postoperative CDVA was available in 8 cases (out of a total of 15 cases with CME after surgery). The mean CDVA improvement was 5.0 G 33.7 ETDRS letters in patients with CME and 9.0 G 26.7 letters in those without CME (n Z 54). There were no statistically significant differences between those with CME and those without CME (mean difference 4 [95% CI, 16.8 to 24.8]). Five patients (5.3%) presented with atrophy at the haptic enclavation site (Figure 4); 4 patients (7%) in the prepupillary group and 1 patient (2.6%) in the retropupillary group. The median time of onset was 16 months and 6 months, respectively. Four eyes (4.2%) developed pupillary distortion (Figure 5), 1 eye (1.8%) in the prepupillary group and 3 eyes (7.9%) in the retropupillary group. Anatomical Alterations in the Iris
Intraocular Pressure In Group 1, the median IOP was 15 mm
Comparative Study Visual Acuity Preoperative and postoperative data were avail-
able in 62 cases (34 in Group 1 and 28 in Group 2). In the prepupillary group, the median CDVA was 65 ETDRS
Table 1. Demographic characteristics of the study patients. Parameter
Prepupillary IOL
Cases, n (%) Sex, n (%) Male Female Age, y (IQR) Eye operated, n (%) Right Left
38 (40)
32 (56.1) 25 (43.9) 66 (21)
20 (52.6) 18 (47.4) 72.5 (15)
26 (45.6) 31 (54.4)
22 16
IOL Z intraocular lens; IQR Z interquartile range
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Retropupillary IOL
57 (60)
(57.9) (42.1)
Hg (IQR Z 6) before surgery and 14 mm Hg (IQR Z 6) after surgery. In Group 2, it was 16 mm Hg (range 12 to 18 mm Hg) before and after surgery. There was no statistically significant difference in IOP before and after surgery within each group or between groups. However, of 67 cases with complete preoperative and postoperative records, 12 cases (12.1%) developed intraocular hypertension (IOP O22.0 mm Hg); 7 cases in the prepupillary group and 5 cases in the retropupillary group. The median time of onset was less than 1 month in both groups. Three of the aforementioned patients had glaucoma before surgery (2 in Group 1 and 1 in Group 2). Only 3 patients (2 in the prepupillary group and 1 in the retropupillary group) presented with ocular hypotony (!6.0 mm Hg) that disappeared within days.
In Group 1, the mean ECC was 1761 G 466 cells/mm2 before surgery and 1640 G 443
Endothelial Cell Density
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Table 2. Preoperative ocular pathology of the study patients. Number (%) Pathology
Prepupillary IOL
Retropupillary IOL
Total
9 (15.8) 1 (1.8) 3 (5.3) 14 (24.6) 14 (24.6) 3 (5.3)
9 (23.7) 3 (7.9) 1 (2.6) 11 (28.9) 12 (31.6) 4 (10.5)
18 (18.9) 4 (4.2) 4 (4.2) 25 (26.3) 26 (27.4) 7 (7.4)
Corneal Iridal Nonreactive mydriasis Glaucoma Retinal Pseudoexfoliation IOL Z intraocular lens
cells/mm2 after surgery. In the cases for which full preoperative and postoperative records were available, the mean reduction in ECC was 166 G 390 cells/mm2 (12 cases, 9.6%, P ! .05). In Group 2, the mean ECC was 1701 G 374 cells/mm2 before surgery and 1538 G 391 cells/mm2 after surgery. In the cases for which full preoperative and postoperative records were available, the mean reduction in ECC was 150 G 406 cells/mm2 (24 cases, 8.7%, P ! .05). There was no statistically significant difference between groups in the reduction of ECC after IOL implantation. Altogether, the mean preoperative cell count was 1717 G 415 cells/mm2, whereas the postoperative cell count was 1563 G 428 cells/mm2, that is, a mean reduction of 155 G 395 cells/mm2 (36 cases, 9.0%, P ! .05). Macular Edema Fifteen patients (16.1%) developed macular edema after IOL implantation, 12 patients (21.8%) in Group 1 and 3 patients (7.9%) in Group 2. The median time of onset was 3 months and 8 months, respectively. Despite the disparity in the percentages, there was no statistically significant difference between groups. Other Complications Only 2 patients presented
with complications during surgery (anterior chamber hemorrhage because of previous iris manipulation, not related to IOL implantation). Regarding postoperative complications, IOL subluxation (Figure 6) was observed in 3 cases (3%); 2 in Group 1 and 1 in Group 2. The median time of onset was 13.5 and 12.0 months, respectively. All cases had reimplantation with success (Figure 7).
Three patients developed retinal detachment (RD), 2 in Group 1 and 1 in Group 2, with a median time of onset of 1 and 8 months, respectively. Endothelial decompensation was noted in only 1 case 3 months after prepupillary IOL implantation. There were no statistically significant differences between groups in the incidence or time of onset of these complications. DISCUSSION Surgical correction of aphakia in the absence of capsular support continues to be a controversial topic. These patients are often complex and present other ocular problems. Treatment alternatives available to date are reported to have different advantages and disadvantages. Scleral-fixated PC IOLs require advanced surgical skills and entail a relatively high intraoperative and postoperative risk,5 whereas AC IOLs, although easier to implant, might cause complications in the iridocorneal angle and the corneal endothelium.6 Iris-claw IOLs were initially designed to be implanted on the anterior surface of the iris (prepupillary). Several studies have reported on the safety and effectiveness of prepupillary iris-claw IOL implantation,4,7–11 although retropupillary implantation has recently become popular.2,3,12,13 The present study aimed to compare the refractive outcomes and incidence of complications after prepupillary or retropupillary Artisan aphakia (model 205) IOL implantation, as well as to establish whether location affects the final results. To our knowledge, only 3 studies have compared the results of iris-claw IOL implantation considering prepupillary or retropupillary location.14–16 The studies recruited fewer patients (n Z 40, n Z 19, and n Z 32, respectively), their
Table 3. Indications for surgery. Number (%) Indication Surgical aphakia IOL subluxation Lens subluxation Trauma Other*
Prepupillary IOL
Retropupillary IOL
Total
15 (26.3) 14 (24.6) 11 (19.3) 14 (24.6) 3 (5.3)
15 (39.5) 10 (26.3) 6 (15.8) 1 (2.6) 6 (1.6)
30 (31.6) 24 (25.3) 17 (17.9) 15 (15.8) 9 (9.5)
IOL Z intraocular lens *Marfan syndrome, lens coloboma
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Figure 3. Preoperative and postoperative CDVA according to intraocular lens location (prepupillary or retropupillary) (CDVA Z corrected distance visual acuity; ETDRS Z Early Treatment Diabetic Retinopathy Study).
Figure 4. The iris atrophy at the haptic enclavation site (arrowhead) is an anatomical alteration caused by the iris-claw intraocular lens, especially in the prepupillary location.
follow-up time was shorter in 2 of them14,16 (6 months in both papers), and in all 3, the authors analyzed fewer parameters than the present study. There are, however, other articles that do not compare both locations, but have a larger sample size and a longer follow-up time,3,4 reaching 320 patients who were followed during 5.3 years in a study conducted by Forlini et al.3 Many authors report surgical aphakia as the most frequent indication for surgery (46% to 65%).4,10,12 Forlini et al.3 included 45% of patients with trauma and Schallenberg et al.2 described 44% of patients with lens luxation. Labeille et al.16 only studied patients with lens or IOL luxation or subluxation. The preoperative situation of patients seems to have a strong influence on postoperative results. The presence of glaucoma and retinal pathology before surgery is described in several papers,2,10 as well as in our study. We observed that 59.7% of patients had a better CDVA after implantation and the gain was significant in both locations (prepupillary and retropupillary), although no differences were observed between groups. In Group 1, 64.7% had a better or equal CDVA at the end of follow-up (median
12 months), with a mean gain of 6.1 ETDRS letters. In Group 2, the CDVA of 71.4% of patients improved or remained the same, with a mean gain of 11.5 letters. Several studies analyzing the refractive outcomes after prepupillary iris-claw IOL implantation report similar data to that reported here. Lett and Chaudhuri10 observed a significant improvement in 66.6% of patients after 15.7 months. G€ uell et al.4 describe an improvement in CDVA of 63.28% 5 years after implantation. Retropupillary series offer slightly better results. Schallenberg et al.2 observed improved CDVA in 70.97% of patients (25.2 months) and Hsing and Lee12 reported improvement in 69% of patients (21.4 months): both gains are lower than in the present study. In those patients who were aphakic before iris-claw IOL implantation, this deficit was corrected before surgery by using spectacle lenses to establish the minimum visual acuity. Nevertheless, correction of vision with aphakia lenses causes spherical aberrations, a reduction in the visual field, and magnification of image size. Any maladjustment of the pupillary distance in the spectacle introduces
Figure 5. Pupillary distortion (ovalization) in the retropupillary irisclaw intraocular lens fixation.
Figure 6. An uncommon postoperative complication of the iris-claw intraocular lens is its subluxation.
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Figure 7. After reimplantation of the intraocular lens.
relatively large errors of refraction, which might influence the preoperative visual acuity. After iris-claw IOL implantation, all of these problems were resolved by obtaining postoperative CDVA. Because disparity in image size was reduced, CDVA might have been affected in this group of patients. This slight difference between prepupillary and retropupillary location might be because retropupillary implantation is technically simpler and seems to better respect ocular anatomy, although these patients might have had a better preoperative visual prognosis. A disadvantage inherent to the iris-claw IOLs is the necessity to create a wide corneal incision, given their size (5.0 mm), which could cause a high level of astigmatism if not adequately managed. All the patients included in the present study were operated on by the same anterior segment surgeon who was accustomed to managing corneal astigmatism. We chose to make a superior incision because superior incisions are better protected by the superior eyelid than large temporal incisions, which are more exposed to trauma and infections. We preferred the residual astigmatism after suture removal to be with the rule (between 70 and 110 degrees) because it is better tolerated. In fact, the initial and final median topographic astigmatism were not significantly different. Twenty-four of our patients presented with an elevation in IOP after surgery, with no differences between groups. These results are comparable to those published by Helvaci et al.14 Although some studies of prepupillary implantation do not mention incidences related to IOP,4,10 some authors have reported an increase in IOP after retropupillary implantation: Schallenberg et al.2 in 3.2% of patients, Faria et al.13 in 11.4% of patients (similar to our findings). In our study, an increase in IOP was observed in 11.5% of patients in Group 1 (3 had glaucoma previously) and 13.2% of patients in Group 2. All the cases were managed with medical treatment. This increase occurred during the first days
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after surgery and was attributable to retention of the ophthalmic viscosurgical device (OVD). Intraocular hypertension (IOP O22.0 mm Hg) after iris-claw IOL surgery might be caused by topical steroid treatment,17 anterior chamber inflammation, transitory OVD retention, or pigment dispersion. Some authors recommend that iris-claw IOLs should not be used in a retropupillary location in patients with pseudoexfoliation syndrome or pigmentary glaucoma.4 Creating a peripheral iridectomy to prevent intraocular hypertension is controversial. G€ uell et al.4 described an incidence of pupillary block of 1.56% because of occlusion of the surgical iridectomy. A peripheral iridectomy had already been performed in many of our patients during previous procedures. In the few remaining cases, we performed an extensive anterior vitrectomy during iris-claw IOL implantation. Moreover, the design of the Artisan iris-claw IOL (concave–convex, vaulted) helps to avoid direct contact with the iris (except at the sites of enclavation), thus reducing the possibility of pupillary block. In our study, we did not find any cases of pupillary block. Cataract surgery can cause a reduction in corneal ECC, especially if the IOL is implanted in the anterior chamber, because of mechanical irritation caused by the surgery and the proximity of the prosthesis.2 Although we found a greater reduction in ECC in the prepupillary group (9.6% versus 8.7%), this difference was not significant. Labeille et al.16 reported a reduction of 20.5%, with no differences between locations; however, they only monitored this parameter for 3 months. Various authors analyzing prepupillary implantation observed the following reductions in ECC: G€ uell et al.,18 10.9% in 3 years, with 7.78% occurring during the first year; Chen et al.,19 9.78% after 3 years; Ye et al.20 did not find differences at 6 months of correction of aphakia combined with pupilloplasty. Riazi et al.21 observed a reduction of 8.1% at 6 months in patients with trauma, and Acar et al.22 observed a reduction of 23.87% (at 15.58 months) in previously vitrectomized patients, suggesting that complex patients and patients with other ocular pathologies might be more vulnerable to cell loss. On the other hand, Shajari et al.23 observed that the use of phakic IOLs caused a larger reduction in ECC when the anterior chamber was less than 3.0 mm deep than when it was more than 3.4 mm. Iris-claw IOL retropupillary implantation does not seem to significantly reduce ECC.2,3,24 Nevertheless, Anbari and Lake,25 Ganesh et al.,26 and Anglada-Escalona et al.27 observed reductions of 11.9% (2 years), 10.74% (6 months), and 13.6% (1 year), respectively, which are slightly larger than those that we found (8.7% [1 year]). Endothelial cell loss is similar in both prepupillary and retropupillary locations, approximately 8% to 12% (except for the study by Acar et al.22). Gicquel et al.11 compared the results of prepupillary and retropupillary implantation of Verisyse iris-claw IOLs.
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They found that prepupillary IOLs caused a greater reduction in ECC than retropupillary IOLs (19.0% versus 3.7%). Our study analyzed Artisan iris-claw IOLs, which are very similar to the Verisyse, and our results seem to support this finding. Some authors, such as Baykara et al.28 recommend that the scleral tunnel technique be used for implanting the iris-claw IOL, suggesting that free corneal incisions, especially at 12 o’clock, might exacerbate cell loss. We cannot confirm this recommendation because we made a superior corneal incision in all cases. Determining the ECC before and after surgery is advisable to prevent complications related to endothelial cell loss, such as corneal decompensation. We only identified 1 case of corneal decompensation in a patient with multiple previous pathology who received a prepupillary IOL (1.0%). This decompensation occurred 3 months after the procedure. A low ECC count together with preexisting conditions and an anterior location of the IOL may have triggered the decompensation. De Silva et al.29 described a similar incidence (1.7%), in patients who received a prepupillary IOL. Other authors who included prepupillary IOLs,4,14,16 and those who included retropupillary IOLs2,3,12,14,16,28 did not find any cases of corneal decompensation. The incidence of CME described in the literature is variable. Scleral-fixated PC IOLs seem to pose a higher risk for producing CME.8 Clinically significant acute pseudophakic CME after cataract surgery appears in 0.6% to 3.6% of cases, with a peak at around 5 weeks. Until recently, fluorescein angiography was considered a gold standard in detecting macular edema, with a nonnegligible prevalence of 9.1% to 25.5%. Optical coherence tomography has replaced fluorescein angiography because it is fast, simple, and noninvasive. Routine use of OCT after cataract surgery might help detect nonclinical CME (! 20/40 change in visual acuity), which is in all probability more prevalent. The global rate of appearance of postoperative CME was 16.1% in our study. However, despite the disparity between groups (21.8% in the prepupillary IOL group and 7.9% in the retropupillary IOL group), the difference was not statistically significant. Helvaci et al.14 did not evaluate the development of CME in a comparative study which included prepupillary and retropupillary iris-claw IOLs. Labeille et al.16 described 10 cases of CME (37%) occurring at 6 months after surgery, although they did not distinguish between locations when giving their results, and they did not consider that the development of edema might have been directly related to surgery because they included patients with other ocular pathologies. The development of CME after prepupillary iris-claw IOL implantation is variable. De Silva et al.29 reported an incidence of 7.7%, G€ uell et al.4 of 3.12%, and Lett and 10 Chaudhuri did not find any cases. We observed that in Group 1, the incidence was much higher (21.8%). The incidence of CME observed in Group 2 in the present study (7.9%) is similar to that reported by Gonnermann
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et al.24 who found an incidence of 8.7%. However, other authors published relatively low rates: Hsing and Lee12 2.9%, Forlini et al.3 0.94%, Faria et al.13 2.8%, and Schallenberg et al.2 0%. These low incidences might have been caused by short follow-up periods and different indications for surgery. Our study contributes interesting findings. We believe that it is the only study that compares the development of CME between both groups (prepupillary and retropupillary) and furthermore, it shows that CME seems to appear earlier with prepupillary IOLs (3 months versus 8 months). Although the etiology of CME is not fully understood, prolapsed or incarcerated vitreous and the presence of inflammation and blood–retinal barrier disruption have been proposed as causative agents. Pseudophakic CME can occur in healthy eyes with no surgical complications, although the aforesaid risk factors increase the likelihood of it occurring. These risk factors comprise pseudophakic CME in the contralateral eye as well as anything that might disrupt the blood–retinal barrier, such as diabetes, uveitis, retinal vein occlusion, retinal degeneration, macular degeneration, epiretinal membranes, prostaglandin analog use, and previous ocular surgery. Our patients can be included in this high-risk group. However, in this study, retropupillary implantation showed a lower incidence of CME (7.9%) than prepupillary implantation (21.8%), as well as a later onset of CME (8 months versus 3 months, respectively). In this regard, at least for retropupillary implantation, CME is possibly not related to the surgery itself, but rather to preexisting ocular pathologies (2 cases of epiretinal membrane and 1 of RD). In addition, in our opinion, simpler manipulation of iridal tissue during retropupillary implantation might cause more postoperative inflammation. The studies published to date are insufficient to compare the time of onset of CME after iris-claw IOL implantation because they did not use OCT as a routine procedure during follow-ups. The incidence of other postoperative complications in the literature is variable because the conditions and characteristics of the patients are quite heterogeneous. The complications detected in this study are comparable to those described in other studies, and they are generally related to the preexisting pathology rather than to the IOL itself. We did not find statistically significant differences between groups in the development of postoperative complications, nor in the time of onset. Iris atrophy at haptic enclavation sites is an adverse effect that has been described in this study, with a low incidence (7% with prepupillary IOLs and 2.6% with retropupillary IOLs) and no differences between groups. This complication was more frequent (7%) and appeared later with prepupillary IOLs (16 months versus 6 months). Schallenberg et al.2 reported an incidence of 12.9% with retropupillary IOLs. We did not find this condition in other studies, and we were not able to establish whether it is related to
TWO LOCATIONS FOR IRIS-CLAW IOL IMPLANTATION
IOL subluxation. Iris atrophy is probably proportional to the difficulty of haptics enclavation during the procedure and therefore to the surgeon’s skills. Intraocular lens subluxation, caused by inadequate enclavation of the haptics, was noted in 3.0% of our patients (3.3% prepupillary at 13.5 months; 2.6% retropupillary at 12 months). Forlini et al.3 report an incidence of 1.0% at 12 months after retropupillary implantation, whereas Schallenberg et al.2 did not find any cases. This finding was not recorded in most studies, possibly because it was not considered a complication. An incorrect maneuver during enclavation can lead to IOL subluxation. Progressive atrophy of the iris at the site of enclavation can also increase the risk for this complication. Reintervention with implantation of a new IOL is considered the best management option. Pupillary distortion or ovalization has been described and is related to excessively peripheral enclavation of the haptics. Schallenberg et al.2 found this complication in 32.0% of their patients after retropupillary implantation. Faria et al.13 described an incidence of 15.3%. Other studies with prepupillary IOLs did not report on this complication.9,29 Our study showed an incidence of 4.2% (1.8% with prepupillary IOLs and 7.9% with retropupillary IOLs), which is lower than that of other studies. We believe that pupillary distortion tends to be more frequent with retropupillary IOLs because of the impossibility of viewing the haptics during the procedure. Other potential complications described in the literature are vitreous prolapse, uveitis, and glaucoma,3,9,13 although we did not find any cases. The incidence of RD seems to be linked to the preoperative situation of the patients rather than to IOL implantation. Some authors do not report any cases,9,12 whereas others publish low incidences with both prepupillary IOLs29 (0.8%) and retropupillary IOLs2,3,13 (0.3% to 3.2%). We observed RD, a severe complication, in 3.5% of prepupillary IOLs and 2.6% of retropupillary IOLs, with no differences according to location. In conclusion, iris-claw IOL implantation, in both prepupillary and retropupillary locations, is a procedure that allows good visual rehabilitation in complex aphakic eyes. Although this study could not demonstrate the superiority of one location over the other, retropupillary implantation seemed to offer better visual results with lower loss of endothelial cells, as well as a lower incidence and later onset of CME. In our opinion, retropupillary implantation is simpler and displays the advantages of posterior chamber implantation, with few intraoperative and postoperative complications. The main limitations of this study were the retrospective design and dropouts during follow-up. Approximately 400 individuals should be enrolled to reach sufficient statistical power to detect differences between groups. Prospective multicenter studies, with a larger sample size, are deemed necessary to demonstrate superiority of one location over the other.
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WHAT WAS KNOWN Iris-claw IOL fixation is an effective option in patients with absence of capsular support and, unlike AC IOLs and scleral-fixated PC IOLs, it seems to have fewer complications. Several studies have evaluated anterior chamber implantation and others have analyzed posterior chamber implantation, but few have compared both locations. Only 3 studies (one of them in penetrating keratoplasty) have compared the results of iris-claw IOL implantation considering its location. All of them have limitations: a low number of patients, short follow-up periods, and analysis of few parameters.
WHAT THIS PAPER ADDS Although the iris-claw IOL provided good visual outcomes with few complications regardless of location, prepupillary IOL implantation seemed to result in greater endothelial cell loss and earlier onset of CME than retropupillary IOL implantation. Given that patients who have this type of procedure are complex and might have other ocular pathologies, it is important to determine whether prepupillary or retropupillary implantation offers better results in the long term. The number of cases, the longer follow-up time, and the multiple parameters analyzed in this study contribute to clarifying this question.
REFERENCES 1. Worst JGF. Iris claw lens [letter]. Am Intra-Ocular Implant Soc J 1980; 6:166–167 2. Schallenberg M, Dekowski D, Hahn A, Laube T, Steuhl K-P, Meller D. Aphakia correction with retropupillary fixated iris-claw lens (Artisan) – long-term results. Clin Ophthalmol 2014; 8:137–141. Available at: https://www.ncbi .nlm.nih.gov/pmc/articles/PMC3878958/pdf/opth-8-137.pdf. Accessed May 16, 2018 3. Forlini M, Soliman W, Bratu A, Rossini P, Cavallini GM, Forlini C. Long-term follow up of retropupillary iris-claw intraocular lens implantation: a retrospective analysis. BMC Ophthalmol 2015; 15:143. Available at: https ://www.ncbi.nlm.nih.gov/pmc/articles/PMC4624704/pdf/12886_2015 _Article_146.pdf. Accessed May 16, 2018 €ell JL, Verdaguer P, Elies D, Gris O, Manero F, Mateu-Figueras G, 4. Gu Morral M. Secondary iris-claw anterior chamber lens implantation in patients with aphakia without capsular support. Br J Ophthalmol 2014; 98:658–663 5. Solomon K, Gussler JR, Gussler C, Van Meter WS. Incidence and management of complications of transsclerally sutured posterior chamber lenses. J Cataract Refract Surg 1993; 19:488–493 6. Sawada T, Kimura W, Kimura T, Suga H, Ohte A, Yamanishi S, Ohara T. Long-term follow-up of primary anterior chamber intraocular lens implantation. J Cataract Refract Surg 1998; 24:1515–1520 7. Wagoner MD, Cox TA, Ariyasu RG, Jacobs DS, Karp CL. Intraocular lens implantation in the absence of capsular support; a report by the American Academy of Ophthalmology (Ophthalmic Technology Assessment). Ophthalmology 2003; 110:840–859 8. Dick HB, Augustin AJ. Lens implant selection with absence of capsular support. Curr Opin Ophthalmol 2001; 12:47–57 9. Zheng D, Wan P, Liang J, Song T, Liu Y. Comparison of clinical outcomes between iris-fixated anterior chamber intraocular lenses and scleral-fixated posterior chamber intraocular lenses in Marfan syndrome with lens subluxation. Clin Exp Ophthalmol 2012; 40:268–274 10. Lett KS, Chaudhuri PR. Visual outcomes following Artisan aphakia iris claw lens implantation. Eye 2011; 25:73–76. Available at: http://www.nature .com/eye/journal/v25/n1/pdf/eye2010146a.pdf. Accessed May 16, 2018 11. Gicquel J-J, Guigou S, Bejjani RA, Briat B, Ellies P, Dighiero P. Ultrasound biomicroscopy study of the Verisyse aphakic intraocular lens combined with
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penetrating keratoplasty in pseudophakic bullous keratopathy. J Cataract Refract Surg 2007; 33:455–464 Hsing YE, Lee GA. Retropupillary iris claw intraocular lens for aphakia. Clin Exp Ophthalmol 2012; 40:849–854 Faria MY, Ferreira NP, Pinto JM, Sousa DC, Leal I, Neto E, MarquesNeves C. Retropupillary iris claw intraocular lens implantation in aphakia for dislocated intraocular lens. Int Med Case Rep J 2016; 9:261–265. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5010170/pdf/imc rj-9-261.pdf. Accessed May 16, 2018 € u €zen S, Oks €z H. Iris-claw intraocular lens implantation: Helvaci S, Demirdu anterior chamber versus retropupillary implantation. Indian J Ophthalmol 2016; 64:45–49. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles /PMC4821121/?reportZprintable. Accessed May 16, 2018 Rijneveld WJ, Beekhuis WH, Hassman EF, Dellaert MMMJD, Gerrards AJM. Iris claw lens: Anterior and posterior iris surface fixation in the absence of capsular support during penetrating keratoplasty. J Refract Corneal Surg 1994; 10:14–19 Labeille E, Burillon C, Cornut P-L. Pars plana vitrectomy combined with irisclaw intraocular lens implantation for lens nucleus and intraocular lens dislocation. J Cataract Refract Surg 2014; 40:1488–1497 Menezo JL, Martinez MC, Cisneros AL. Iris-fixated Worst claw versus sulcus-fixated posterior chamber lenses in the absence of capsular support. J Cataract Refract Surg 1996; 22:1476–1484 zquez M, Gris O, Manero F. Secondary €ell JL, Velasco F, Malecaze F, Va Gu Artisan–Verysise aphakic lens implantation. J Cataract Refract Surg 2005; 31:2266–2271. Available at: https://www.jcrsjournal.org/article/S0886-33 50(05)00798-4/pdf. Accessed May 16, 2018 Chen Y, Liu Q, Xue C, Huang Z, Chen Y. Three-year follow-up of secondary anterior iris fixation of an aphakic intraocular lens to correct aphakia. J Cataract Refract Surg 2012; 38:1595–1601 Ye P, He F, Shi J, Liu J, Liang G, Wu J, Xu W. Artisan iris-fixated intraocular lens implantation in combination with pupilloplasty–correction of aphakia with pathologically large pupil and insufficient capsular support. Can J Ophthalmol 2017; 52:155–160 Riazi M, Moghimi S, Najmi Z, Ghaffari R. Secondary Artisan–Verysise intraocular lens implantation for aphakic correction in post-traumatic vitrectomized eye. Eye 2008; 22:1419–1424. Available at: http://www.nature.com /eye/journal/v22/n11/pdf/eye2008271a.pdf. Accessed May 16, 2018 Acar N, Kapran Z, Altan T, Kucuksumer Y, Unver YB, Polat E. Secondary iris claw intraocular lens implantation for the correction of aphakia after pars plana vitrectomy. Retina 2010; 30:131–139 Shajari M, Scheffel M, Koss MJ, Kohnen T. Dependency of endothelial cell loss on anterior chamber depth within first 4 years after implantation of irissupported phakic intraocular lenses to treat high myopia. J Cataract Refract Surg 2016; 42:1562–1569
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24. Gonnermann J, Amiri S, Klamann M, Maier A-KB, Joussen AM, Rieck PW, Torun N, Bertelmann E. Endothelzellverlust nach retropupillar fixierter Irisklauen-Linse [Endothelial cell loss after retropupillary iris-claw intraocular lens implantation]. Klin Monbl Augenheilkd 2014; 231:784–787 25. Anbari A, Lake DB. Posteriorly enclavated iris claw intraocular lens for aphakia: long-term corneal endothelial safety study. Eur J Ophthalmol 2015; 25:208–213 26. Ganesh S, Brar S, Relekar K. Long term clinical and visual outcomes of retrofixated iris claw lenses implantation in complicated cases. Open Ophthalmol J 2016; 10:111–118. Available at: https://www.ncbi.nlm.nih.gov/pmc /articles/PMC4899510/pdf/TOOPHTJ-10-111.pdf. Accessed May 16, 2018 Sabala27. Anglada-Escalona R, Castellví-Manent J, Parera-Arranz MA, Llopart A. Inverted implantation of posterior iris fixated intraocular lens with 23G transconjunctival vitrectomy in the management of secondary implantTechnique and stability, astigmatism and endothelial loss outcomes. J Emmetropia 2014; 5:133–143. Available at: http://www.journalofemmet ropia.org/numeros/pdf/5-3/Journal-article-3.pdf. Accessed May 16, 2018 € Posterior iris fixation of the iris28. Baykara M, Ozcetin H, Yilmaz S, Timuc¸in OB. claw intraocular lens implantation through a scleral tunnel incision. Am J Ophthalmol 2007; 144:586–591 29. De Silva SR, Arun K, Anandan M, Glover N, Patel CK, Rosen P. Iris-claw intraocular lenses to correct aphakia in the absence of capsule support. J Cataract Refract Surg 2011; 37:1667–1672 OTHER CITED MATERIAL A. Ophtec BV. Artisan Aphakia model 205. Available at: https://www.ophtec .com/products/cataract-surgery/iols/artisan-aphakia. Accessed May 16, 2018.
Disclosures: None of the authors has a financial or proprietary interest in any material or method mentioned.
First author:
~o Peralba, MD, PhD Rosario Tourin Cornea and Ocular Surface Unit, Ophthalmology Department, Complejo Hospitalario Universitario de Santiago de Compostela, Santiago de Compostela, Spain
ARTICLE
Iris-claw intraocular lens for aphakia: Can location influence the final outcomes? Rosario Touri~ no Peralba, MD, PhD, David Lamas-Francis, MD, Teresa Sarandeses-Diez, MD, Laura Martínez-Perez, MD, PhD, Teresa Rodríguez-Ares, MD, PhD
Purpose: To describe the demographic data, evaluate the longterm refractive and anatomical outcomes, and report the incidence of complications of anterior iris (prepupillary) and posterior iris (retropupillary) fixation of the Artisan aphakia iris-claw intraocular lens (IOL).
Setting: Complejo Hospitalario Universitario de Santiago de Compostela, Spain. Design: Retrospective case series. Methods: Patients who had iris-claw IOL implantation were
had retropupillary implantation. Indications for surgery were IOL luxation or subluxation (n Z 24), lens luxation or subluxation (n Z 17), trauma (n Z 15), aphakia (n Z 30), and other (n Z 9). The CDVA improved significantly in both groups and there were no differences between them. A significant ECC reduction was observed in both groups, with no differences between them. The incidence of CME was 16.1% (21.8% in the prepupillary group and 7.9% in the retropupillary group at 3 months and 8 months, respectively), although the difference was not statistically significant. Other postoperative complications were rare and no differences were found between groups.
divided into 2 groups: Group 1 (prepupillary) and Group 2 (retropupillary). The corrected distance visual acuity (CDVA), anatomical changes, endothelial cell count (ECC), presence of cystoid macular edema (CME), and operative and postoperative complications were determined.
Conclusions: Irrespective of location, the iris-claw IOL provided good visual outcomes with few complications. However, prepupillary IOL implantation seemed to contribute to greater endothelial cell loss and earlier onset of CME.
Results: The study comprised 95 eyes of 95 patients. Fiftyseven patients had prepupillary implantation and 38 patients
J Cataract Refract Surg 2018; 44:818–826 Q 2018 ASCRS and ESCRS
I
ntracapsular intraocular lens (IOL) implantation remains the ideal procedure after cataract extraction. However, alternative methods of IOL implantation should be considered in some cases, such as capsular rupture and significant zonular dehiscence during cataract surgery, as well as weakened zonular fibers because of trauma, pseudoexfoliation syndrome, pathological myopia, uveitis, or hypermature cataracts, or because of Marfan syndrome or Weill-Marchesani syndrome. Surgeons might choose to implant an anterior chamber IOL (AC IOL) (also known as angle-supported IOL) or a scleral-fixated IOL. However, neither of these procedures are exempt from complications. Use of AC IOLs might lead to reduced endothelial cell count (ECC) and corneal
decompensation, secondary glaucoma, and chronic inflammation. Scleral-fixated posterior chamber IOLs (PC IOLs) might also cause inflammation, retinal tears, choroidal hematoma, and cystoid macular edema (CME). Iris-claw IOLs were designed by Jan Worst in 19781 to correct aphakia after intracapsular cataract surgery. The Artisan aphakia 205 IOLA (Ophtec BV) is a 1-piece biconvex, made of poly(methyl methacrylate), 8.5 mm long (7.5 mm for pediatric patients), and it has an optic zone of 5.0 mm. This IOL was originally designed to be placed over the anterior surface of the iris. The haptics are fixed to an avascular portion of the iris without sutures. The IOL can be easily centered and it does not come into contact with the anterior chamber angle.1 Several studies
Submitted: November 4, 2017 | Final revision submitted: April 15, 2018 | Accepted: May 4, 2018 ~o Peralba, Lamas-Francis, Sarandeses-Diez, Martínez-Pe rez, Rodríguez-Ares), Ophthalmology Department, Complejo From the Cornea and Ocular Surface Unit (Tourin ~o Peralba, Rodríguez-Ares), Medical School, Santiago de Compostela Hospitalario Universitario de Santiago de Compostela and the Surgery Department (Tourin University, Santiago de Compostela, Spain. Presented at the XXXV Congress of the European Society of Cataract and Refractive Surgeons, Lisbon, Portugal, October 2017. Francisco Gude Sampedro, MD, PhD, Clinical Epidemiology Unit, University Hospital of Santiago de Compostela, revised the statistics for this paper and provided technical advice. ~o Peralba, MD, PhD, Cornea and Ocular Surface Unit, Ophthalmology Department, Complejo Hospitalario Universitario de Santiago Corresponding author: Rosario Tourin n Baltar s/n CP 15706, Santiago de Compostela (A Corun ~a), Spain. Email: [email protected]. a Ramo de Compostela, Ru Q 2018 ASCRS and ESCRS Published by Elsevier Inc.
0886-3350/$ - see frontmatter https://doi.org/10.1016/j.jcrs.2018.05.010
TWO LOCATIONS FOR IRIS-CLAW IOL IMPLANTATION
have reported on the safety and effectiveness of this IOL in both positions: anterior chamber (prepupillary) and posterior chamber (retropupillary).2–4 This study aimed to analyze the viability and safety of Artisan iris-claw IOL implantation in the absence of capsular support, as well as to determine whether anterior iris (prepupillary) or posterior iris (retropupillary) location influence the final visual and anatomical results. PATIENTS AND METHODS This retrospective cohort study included patients who had irisclaw IOL implantation consecutively between 2006 and 2016 at the University Hospital in Santiago de Compostela, Spain. All patients were previously informed about the procedure and its risks and signed a specific informed consent form before implantation. This study was conducted in accordance with the tenets of the Declaration of Helsinki and approved by the Galician research ethics committee (registration code 2017/127). The inclusion criteria were as follows: subluxation of preexisting IOL (degrees 1, 2, and 3), lens subluxation (pseudoexfoliation syndrome, Marfan syndrome, lens coloboma, and other pathologies), trauma and aphakia without capsular support. All patients presented with an iris morphology that allowed a stable IOL placement. The exclusion criteria were as follows: iris abnormalities hampering enclavation (mydriasis O5.0 mm or absence of iris), history of ocular inflammation in the previous 6 months, uncontrolled intraocular pressure (IOP), severe corneal opacity, and poor visual prognosis. All procedures were performed by the same anterior segment surgeon (R.T.). Iris-claw IOL implantation was carried out as a primary or secondary procedure. The patients were divided into 2 groups: Group 1, anterior chamber (prepupillary) implantations (Figure 1) and Group 2, posterior chamber (retropupillary) implantations (Figure 2). The surgeon identified the best location in each case (prepupillary or retropupillary), according to anterior chamber depth, ECC, presence of glaucoma (especially pigmentary glaucoma), and anatomical complexity. The IOL was always retropupillary when the anterior chamber was less than 3.0 mm, the ECC was less than 1200 cells/mm2, or in the presence of pigmentary glaucoma or advanced glaucoma. Surgical Technique Anesthesia was peribulbar or topical depending on the patient’s requirements and the surgeon’s preference. The A-constant used
Figure 1. Iris-claw intraocular lens to correct the aphakia in absence of capsular support. Anterior iris surface fixation (prepupillary location).
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was 115.0 (prepupillary) and 116.8 (retropupillary). A superior clear corneal incision was made for both locations (prepupillary and retropupillary). It is important to immobilize the IOL correctly with special forceps (Shepard forceps). Prepupillary IOLs were stabilized with these forceps at the optics and the midperipheral iris was fixated to the haptics with a needle inserted through the paracenteses (10 o’clock and 2 o’clock). Retropupillary IOLs were pushed behind the iris, 1 haptic after the other. It is important to grasp a large part of the body of the IOL with the Shepard forceps to prevent its displacement, especially when enclavating the midperipheral iris into the haptics. A reverse Sinskey hook or a 27-gauge needle bent 45 degrees was passed through the paracenteses (3 o’clock and 9 o’clock) to enclavate a sufficient portion of iridal tissue. The ideal interlocking of the iris-claw IOL was considered correct when dimples were visible on the iris. This helps prevent spontaneous detachment of the IOL into the vitreous cavity. The corneal wound was sutured with 10-0 nylon suture and selectively removed after 8 weeks, depending on the patient’s refractive and topographical astigmatism. Steroid and antibiotic eyedrops were prescribed for 1 month. Data Collection Demographic, clinical, and surgical characteristics were obtained retrospectively from medical records. The demographic data analyzed included age, sex, eye operated, etiology of aphakia, and preoperative eye pathology. The following clinical parameters were collected preoperatively and at 1, 3, and 6 months and annual visits postoperatively: The corrected distance visual acuity (CDVA) registered with a logarithm of the minimum angle of resolution chart in Early Treatment Diabetic Retinopathy Study (ETDRS) letters. Corneal astigmatism was measured using the Scheimpflug system (Pentacam, Oculus Optikger€ate GmbH). Postoperative corneal astigmatism was recorded when it remained stable after suture removal. Slitlamp evaluation: anatomical changes on the iris related to IOL implantation (pupil deformity and atrophy at the haptic enclavation site). Intraocular pressure measured with the Perkins applanation tonometer. Intraocular hypertension was defined as IOP of 22.0 mm Hg or higher and hypotony as 6.0 mm Hg or lower. The ECC was obtained using specular microscopy (Ophthaltec, Costruzione Strumenti Oftalmici). The macular evaluation with optical coherence tomography (OCT) (Cirrus 500, Carl Zeiss Meditec AG) determined the presence of edema.
Figure 2. Iris-claw intraocular lens with posterior iris surface fixation (retropupillary location).
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Surgical data included the following: primary or secondary IOL implantation, location (prepupillary or retropupillary), position (horizontal, vertical, or oblique), operative and postoperative complications (ECC decrease, CME, etc.). Statistical Analysis The Kolmogorov-Smirnov test with Lilliefors correction was used to determine whether the continuous variables were normally distributed. The mean G SD values or median values and interquartile ranges (IQRs) are presented. Categorical variables are given as numbers and percentages. Chi-square, Student t test, and Mann-Whitney U test were used to compare the groups. Differences were considered statistically significant at a P value less than 0.05. All analyses were conducted using SPSS software (version 19.0, IBM Corp.) and R (version V3.1.2, R Foundation for Statistical Computing).
RESULTS Descriptive Results
The study comprised 95 eyes of 95 patients (43 women [45.3%], 52 men [54.7%]). Table 1 shows the demographic characteristics of the study patients. There were 48 right eyes (50.5%) and 47 left eyes (49.5%). Fifty-seven patients (60.0%) received a prepupillary IOL and 38 patients (40.0%) received a retropupillary IOL. The median age at the time of surgery was 67 years (IQR Z 21). The patients were followed between 1 month and 6 years (median 12 months, IQR Z 18). There was no statistically significant difference in preoperative ocular pathology between the groups. Table 2 shows the most frequent conditions. The most common indications for IOL implantation were surgical aphakia (n Z 30) and IOL subluxation (n Z 24). Table 3 shows the indications for surgery. Intraocular lens implantation was performed as a primary procedure in 56 patients (58.9%) (36 prepupillary, 20 retropupillary) and as a secondary procedure in 39 patients (41.1%) (21 prepupillary, 18 retropupillary). The iris-claw IOL was placed in a horizontal position in 90 eyes (94.7%), an oblique position in 4 eyes (4.2%), or a vertical position in 1 eye (1.1%).
letters (IQR Z 28) before surgery and 75 ETDRS letters (IQR Z 18) after surgery. This improvement was statistically significant. The mean gain was 6.1 G 27.5 letters. After surgery, the CDVA was higher in 20 patients (58.8%), remained the same in 2 patients (5.9%), and was lower in 12 patients (35.3%). In the retropupillary group, the median CDVA was 50 ETDRS letters (IQR Z 48.5) before surgery and 65 ETDRS letters (IQR Z 42.0) after surgery. This improvement was also statistically significant. The mean gain was 11.5 G 27.1 letters. After surgery, the CDVA was higher in 17 patients (60.7%), remained the same in 3 patients (10.7%), and was lower in 8 patients (28.6%). However, there were no statistically significant differences in CDVA improvement between Groups 1 and 2 (Figure 3). The mean difference was 5.4 ETDRS letters (95% confidence interval [CI], 8.5 to 19.3). The median topographic astigmatism was 1.3 diopters (D) (IQR Z 3.0) before surgery and 1.9 D (IQR Z 2.2) (not statistically significant). In the prepupillary group, these results were 1.5 D (IQR Z 5.1) and 1.95 D (IQR Z 2.5), respectively; and 1.3 D (IQR Z 2.7) and 1.8 D (IQR Z 2.1) in the retropupillary group. Preoperative and postoperative CDVA was available in 8 cases (out of a total of 15 cases with CME after surgery). The mean CDVA improvement was 5.0 G 33.7 ETDRS letters in patients with CME and 9.0 G 26.7 letters in those without CME (n Z 54). There were no statistically significant differences between those with CME and those without CME (mean difference 4 [95% CI, 16.8 to 24.8]). Five patients (5.3%) presented with atrophy at the haptic enclavation site (Figure 4); 4 patients (7%) in the prepupillary group and 1 patient (2.6%) in the retropupillary group. The median time of onset was 16 months and 6 months, respectively. Four eyes (4.2%) developed pupillary distortion (Figure 5), 1 eye (1.8%) in the prepupillary group and 3 eyes (7.9%) in the retropupillary group. Anatomical Alterations in the Iris
Intraocular Pressure In Group 1, the median IOP was 15 mm
Comparative Study Visual Acuity Preoperative and postoperative data were avail-
able in 62 cases (34 in Group 1 and 28 in Group 2). In the prepupillary group, the median CDVA was 65 ETDRS
Table 1. Demographic characteristics of the study patients. Parameter
Prepupillary IOL
Cases, n (%) Sex, n (%) Male Female Age, y (IQR) Eye operated, n (%) Right Left
38 (40)
32 (56.1) 25 (43.9) 66 (21)
20 (52.6) 18 (47.4) 72.5 (15)
26 (45.6) 31 (54.4)
22 16
IOL Z intraocular lens; IQR Z interquartile range
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Retropupillary IOL
57 (60)
(57.9) (42.1)
Hg (IQR Z 6) before surgery and 14 mm Hg (IQR Z 6) after surgery. In Group 2, it was 16 mm Hg (range 12 to 18 mm Hg) before and after surgery. There was no statistically significant difference in IOP before and after surgery within each group or between groups. However, of 67 cases with complete preoperative and postoperative records, 12 cases (12.1%) developed intraocular hypertension (IOP O22.0 mm Hg); 7 cases in the prepupillary group and 5 cases in the retropupillary group. The median time of onset was less than 1 month in both groups. Three of the aforementioned patients had glaucoma before surgery (2 in Group 1 and 1 in Group 2). Only 3 patients (2 in the prepupillary group and 1 in the retropupillary group) presented with ocular hypotony (!6.0 mm Hg) that disappeared within days.
In Group 1, the mean ECC was 1761 G 466 cells/mm2 before surgery and 1640 G 443
Endothelial Cell Density
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TWO LOCATIONS FOR IRIS-CLAW IOL IMPLANTATION
Table 2. Preoperative ocular pathology of the study patients. Number (%) Pathology
Prepupillary IOL
Retropupillary IOL
Total
9 (15.8) 1 (1.8) 3 (5.3) 14 (24.6) 14 (24.6) 3 (5.3)
9 (23.7) 3 (7.9) 1 (2.6) 11 (28.9) 12 (31.6) 4 (10.5)
18 (18.9) 4 (4.2) 4 (4.2) 25 (26.3) 26 (27.4) 7 (7.4)
Corneal Iridal Nonreactive mydriasis Glaucoma Retinal Pseudoexfoliation IOL Z intraocular lens
cells/mm2 after surgery. In the cases for which full preoperative and postoperative records were available, the mean reduction in ECC was 166 G 390 cells/mm2 (12 cases, 9.6%, P ! .05). In Group 2, the mean ECC was 1701 G 374 cells/mm2 before surgery and 1538 G 391 cells/mm2 after surgery. In the cases for which full preoperative and postoperative records were available, the mean reduction in ECC was 150 G 406 cells/mm2 (24 cases, 8.7%, P ! .05). There was no statistically significant difference between groups in the reduction of ECC after IOL implantation. Altogether, the mean preoperative cell count was 1717 G 415 cells/mm2, whereas the postoperative cell count was 1563 G 428 cells/mm2, that is, a mean reduction of 155 G 395 cells/mm2 (36 cases, 9.0%, P ! .05). Macular Edema Fifteen patients (16.1%) developed macular edema after IOL implantation, 12 patients (21.8%) in Group 1 and 3 patients (7.9%) in Group 2. The median time of onset was 3 months and 8 months, respectively. Despite the disparity in the percentages, there was no statistically significant difference between groups. Other Complications Only 2 patients presented
with complications during surgery (anterior chamber hemorrhage because of previous iris manipulation, not related to IOL implantation). Regarding postoperative complications, IOL subluxation (Figure 6) was observed in 3 cases (3%); 2 in Group 1 and 1 in Group 2. The median time of onset was 13.5 and 12.0 months, respectively. All cases had reimplantation with success (Figure 7).
Three patients developed retinal detachment (RD), 2 in Group 1 and 1 in Group 2, with a median time of onset of 1 and 8 months, respectively. Endothelial decompensation was noted in only 1 case 3 months after prepupillary IOL implantation. There were no statistically significant differences between groups in the incidence or time of onset of these complications. DISCUSSION Surgical correction of aphakia in the absence of capsular support continues to be a controversial topic. These patients are often complex and present other ocular problems. Treatment alternatives available to date are reported to have different advantages and disadvantages. Scleral-fixated PC IOLs require advanced surgical skills and entail a relatively high intraoperative and postoperative risk,5 whereas AC IOLs, although easier to implant, might cause complications in the iridocorneal angle and the corneal endothelium.6 Iris-claw IOLs were initially designed to be implanted on the anterior surface of the iris (prepupillary). Several studies have reported on the safety and effectiveness of prepupillary iris-claw IOL implantation,4,7–11 although retropupillary implantation has recently become popular.2,3,12,13 The present study aimed to compare the refractive outcomes and incidence of complications after prepupillary or retropupillary Artisan aphakia (model 205) IOL implantation, as well as to establish whether location affects the final results. To our knowledge, only 3 studies have compared the results of iris-claw IOL implantation considering prepupillary or retropupillary location.14–16 The studies recruited fewer patients (n Z 40, n Z 19, and n Z 32, respectively), their
Table 3. Indications for surgery. Number (%) Indication Surgical aphakia IOL subluxation Lens subluxation Trauma Other*
Prepupillary IOL
Retropupillary IOL
Total
15 (26.3) 14 (24.6) 11 (19.3) 14 (24.6) 3 (5.3)
15 (39.5) 10 (26.3) 6 (15.8) 1 (2.6) 6 (1.6)
30 (31.6) 24 (25.3) 17 (17.9) 15 (15.8) 9 (9.5)
IOL Z intraocular lens *Marfan syndrome, lens coloboma
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TWO LOCATIONS FOR IRIS-CLAW IOL IMPLANTATION
Figure 3. Preoperative and postoperative CDVA according to intraocular lens location (prepupillary or retropupillary) (CDVA Z corrected distance visual acuity; ETDRS Z Early Treatment Diabetic Retinopathy Study).
Figure 4. The iris atrophy at the haptic enclavation site (arrowhead) is an anatomical alteration caused by the iris-claw intraocular lens, especially in the prepupillary location.
follow-up time was shorter in 2 of them14,16 (6 months in both papers), and in all 3, the authors analyzed fewer parameters than the present study. There are, however, other articles that do not compare both locations, but have a larger sample size and a longer follow-up time,3,4 reaching 320 patients who were followed during 5.3 years in a study conducted by Forlini et al.3 Many authors report surgical aphakia as the most frequent indication for surgery (46% to 65%).4,10,12 Forlini et al.3 included 45% of patients with trauma and Schallenberg et al.2 described 44% of patients with lens luxation. Labeille et al.16 only studied patients with lens or IOL luxation or subluxation. The preoperative situation of patients seems to have a strong influence on postoperative results. The presence of glaucoma and retinal pathology before surgery is described in several papers,2,10 as well as in our study. We observed that 59.7% of patients had a better CDVA after implantation and the gain was significant in both locations (prepupillary and retropupillary), although no differences were observed between groups. In Group 1, 64.7% had a better or equal CDVA at the end of follow-up (median
12 months), with a mean gain of 6.1 ETDRS letters. In Group 2, the CDVA of 71.4% of patients improved or remained the same, with a mean gain of 11.5 letters. Several studies analyzing the refractive outcomes after prepupillary iris-claw IOL implantation report similar data to that reported here. Lett and Chaudhuri10 observed a significant improvement in 66.6% of patients after 15.7 months. G€ uell et al.4 describe an improvement in CDVA of 63.28% 5 years after implantation. Retropupillary series offer slightly better results. Schallenberg et al.2 observed improved CDVA in 70.97% of patients (25.2 months) and Hsing and Lee12 reported improvement in 69% of patients (21.4 months): both gains are lower than in the present study. In those patients who were aphakic before iris-claw IOL implantation, this deficit was corrected before surgery by using spectacle lenses to establish the minimum visual acuity. Nevertheless, correction of vision with aphakia lenses causes spherical aberrations, a reduction in the visual field, and magnification of image size. Any maladjustment of the pupillary distance in the spectacle introduces
Figure 5. Pupillary distortion (ovalization) in the retropupillary irisclaw intraocular lens fixation.
Figure 6. An uncommon postoperative complication of the iris-claw intraocular lens is its subluxation.
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TWO LOCATIONS FOR IRIS-CLAW IOL IMPLANTATION
Figure 7. After reimplantation of the intraocular lens.
relatively large errors of refraction, which might influence the preoperative visual acuity. After iris-claw IOL implantation, all of these problems were resolved by obtaining postoperative CDVA. Because disparity in image size was reduced, CDVA might have been affected in this group of patients. This slight difference between prepupillary and retropupillary location might be because retropupillary implantation is technically simpler and seems to better respect ocular anatomy, although these patients might have had a better preoperative visual prognosis. A disadvantage inherent to the iris-claw IOLs is the necessity to create a wide corneal incision, given their size (5.0 mm), which could cause a high level of astigmatism if not adequately managed. All the patients included in the present study were operated on by the same anterior segment surgeon who was accustomed to managing corneal astigmatism. We chose to make a superior incision because superior incisions are better protected by the superior eyelid than large temporal incisions, which are more exposed to trauma and infections. We preferred the residual astigmatism after suture removal to be with the rule (between 70 and 110 degrees) because it is better tolerated. In fact, the initial and final median topographic astigmatism were not significantly different. Twenty-four of our patients presented with an elevation in IOP after surgery, with no differences between groups. These results are comparable to those published by Helvaci et al.14 Although some studies of prepupillary implantation do not mention incidences related to IOP,4,10 some authors have reported an increase in IOP after retropupillary implantation: Schallenberg et al.2 in 3.2% of patients, Faria et al.13 in 11.4% of patients (similar to our findings). In our study, an increase in IOP was observed in 11.5% of patients in Group 1 (3 had glaucoma previously) and 13.2% of patients in Group 2. All the cases were managed with medical treatment. This increase occurred during the first days
823
after surgery and was attributable to retention of the ophthalmic viscosurgical device (OVD). Intraocular hypertension (IOP O22.0 mm Hg) after iris-claw IOL surgery might be caused by topical steroid treatment,17 anterior chamber inflammation, transitory OVD retention, or pigment dispersion. Some authors recommend that iris-claw IOLs should not be used in a retropupillary location in patients with pseudoexfoliation syndrome or pigmentary glaucoma.4 Creating a peripheral iridectomy to prevent intraocular hypertension is controversial. G€ uell et al.4 described an incidence of pupillary block of 1.56% because of occlusion of the surgical iridectomy. A peripheral iridectomy had already been performed in many of our patients during previous procedures. In the few remaining cases, we performed an extensive anterior vitrectomy during iris-claw IOL implantation. Moreover, the design of the Artisan iris-claw IOL (concave–convex, vaulted) helps to avoid direct contact with the iris (except at the sites of enclavation), thus reducing the possibility of pupillary block. In our study, we did not find any cases of pupillary block. Cataract surgery can cause a reduction in corneal ECC, especially if the IOL is implanted in the anterior chamber, because of mechanical irritation caused by the surgery and the proximity of the prosthesis.2 Although we found a greater reduction in ECC in the prepupillary group (9.6% versus 8.7%), this difference was not significant. Labeille et al.16 reported a reduction of 20.5%, with no differences between locations; however, they only monitored this parameter for 3 months. Various authors analyzing prepupillary implantation observed the following reductions in ECC: G€ uell et al.,18 10.9% in 3 years, with 7.78% occurring during the first year; Chen et al.,19 9.78% after 3 years; Ye et al.20 did not find differences at 6 months of correction of aphakia combined with pupilloplasty. Riazi et al.21 observed a reduction of 8.1% at 6 months in patients with trauma, and Acar et al.22 observed a reduction of 23.87% (at 15.58 months) in previously vitrectomized patients, suggesting that complex patients and patients with other ocular pathologies might be more vulnerable to cell loss. On the other hand, Shajari et al.23 observed that the use of phakic IOLs caused a larger reduction in ECC when the anterior chamber was less than 3.0 mm deep than when it was more than 3.4 mm. Iris-claw IOL retropupillary implantation does not seem to significantly reduce ECC.2,3,24 Nevertheless, Anbari and Lake,25 Ganesh et al.,26 and Anglada-Escalona et al.27 observed reductions of 11.9% (2 years), 10.74% (6 months), and 13.6% (1 year), respectively, which are slightly larger than those that we found (8.7% [1 year]). Endothelial cell loss is similar in both prepupillary and retropupillary locations, approximately 8% to 12% (except for the study by Acar et al.22). Gicquel et al.11 compared the results of prepupillary and retropupillary implantation of Verisyse iris-claw IOLs.
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They found that prepupillary IOLs caused a greater reduction in ECC than retropupillary IOLs (19.0% versus 3.7%). Our study analyzed Artisan iris-claw IOLs, which are very similar to the Verisyse, and our results seem to support this finding. Some authors, such as Baykara et al.28 recommend that the scleral tunnel technique be used for implanting the iris-claw IOL, suggesting that free corneal incisions, especially at 12 o’clock, might exacerbate cell loss. We cannot confirm this recommendation because we made a superior corneal incision in all cases. Determining the ECC before and after surgery is advisable to prevent complications related to endothelial cell loss, such as corneal decompensation. We only identified 1 case of corneal decompensation in a patient with multiple previous pathology who received a prepupillary IOL (1.0%). This decompensation occurred 3 months after the procedure. A low ECC count together with preexisting conditions and an anterior location of the IOL may have triggered the decompensation. De Silva et al.29 described a similar incidence (1.7%), in patients who received a prepupillary IOL. Other authors who included prepupillary IOLs,4,14,16 and those who included retropupillary IOLs2,3,12,14,16,28 did not find any cases of corneal decompensation. The incidence of CME described in the literature is variable. Scleral-fixated PC IOLs seem to pose a higher risk for producing CME.8 Clinically significant acute pseudophakic CME after cataract surgery appears in 0.6% to 3.6% of cases, with a peak at around 5 weeks. Until recently, fluorescein angiography was considered a gold standard in detecting macular edema, with a nonnegligible prevalence of 9.1% to 25.5%. Optical coherence tomography has replaced fluorescein angiography because it is fast, simple, and noninvasive. Routine use of OCT after cataract surgery might help detect nonclinical CME (! 20/40 change in visual acuity), which is in all probability more prevalent. The global rate of appearance of postoperative CME was 16.1% in our study. However, despite the disparity between groups (21.8% in the prepupillary IOL group and 7.9% in the retropupillary IOL group), the difference was not statistically significant. Helvaci et al.14 did not evaluate the development of CME in a comparative study which included prepupillary and retropupillary iris-claw IOLs. Labeille et al.16 described 10 cases of CME (37%) occurring at 6 months after surgery, although they did not distinguish between locations when giving their results, and they did not consider that the development of edema might have been directly related to surgery because they included patients with other ocular pathologies. The development of CME after prepupillary iris-claw IOL implantation is variable. De Silva et al.29 reported an incidence of 7.7%, G€ uell et al.4 of 3.12%, and Lett and 10 Chaudhuri did not find any cases. We observed that in Group 1, the incidence was much higher (21.8%). The incidence of CME observed in Group 2 in the present study (7.9%) is similar to that reported by Gonnermann
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et al.24 who found an incidence of 8.7%. However, other authors published relatively low rates: Hsing and Lee12 2.9%, Forlini et al.3 0.94%, Faria et al.13 2.8%, and Schallenberg et al.2 0%. These low incidences might have been caused by short follow-up periods and different indications for surgery. Our study contributes interesting findings. We believe that it is the only study that compares the development of CME between both groups (prepupillary and retropupillary) and furthermore, it shows that CME seems to appear earlier with prepupillary IOLs (3 months versus 8 months). Although the etiology of CME is not fully understood, prolapsed or incarcerated vitreous and the presence of inflammation and blood–retinal barrier disruption have been proposed as causative agents. Pseudophakic CME can occur in healthy eyes with no surgical complications, although the aforesaid risk factors increase the likelihood of it occurring. These risk factors comprise pseudophakic CME in the contralateral eye as well as anything that might disrupt the blood–retinal barrier, such as diabetes, uveitis, retinal vein occlusion, retinal degeneration, macular degeneration, epiretinal membranes, prostaglandin analog use, and previous ocular surgery. Our patients can be included in this high-risk group. However, in this study, retropupillary implantation showed a lower incidence of CME (7.9%) than prepupillary implantation (21.8%), as well as a later onset of CME (8 months versus 3 months, respectively). In this regard, at least for retropupillary implantation, CME is possibly not related to the surgery itself, but rather to preexisting ocular pathologies (2 cases of epiretinal membrane and 1 of RD). In addition, in our opinion, simpler manipulation of iridal tissue during retropupillary implantation might cause more postoperative inflammation. The studies published to date are insufficient to compare the time of onset of CME after iris-claw IOL implantation because they did not use OCT as a routine procedure during follow-ups. The incidence of other postoperative complications in the literature is variable because the conditions and characteristics of the patients are quite heterogeneous. The complications detected in this study are comparable to those described in other studies, and they are generally related to the preexisting pathology rather than to the IOL itself. We did not find statistically significant differences between groups in the development of postoperative complications, nor in the time of onset. Iris atrophy at haptic enclavation sites is an adverse effect that has been described in this study, with a low incidence (7% with prepupillary IOLs and 2.6% with retropupillary IOLs) and no differences between groups. This complication was more frequent (7%) and appeared later with prepupillary IOLs (16 months versus 6 months). Schallenberg et al.2 reported an incidence of 12.9% with retropupillary IOLs. We did not find this condition in other studies, and we were not able to establish whether it is related to
TWO LOCATIONS FOR IRIS-CLAW IOL IMPLANTATION
IOL subluxation. Iris atrophy is probably proportional to the difficulty of haptics enclavation during the procedure and therefore to the surgeon’s skills. Intraocular lens subluxation, caused by inadequate enclavation of the haptics, was noted in 3.0% of our patients (3.3% prepupillary at 13.5 months; 2.6% retropupillary at 12 months). Forlini et al.3 report an incidence of 1.0% at 12 months after retropupillary implantation, whereas Schallenberg et al.2 did not find any cases. This finding was not recorded in most studies, possibly because it was not considered a complication. An incorrect maneuver during enclavation can lead to IOL subluxation. Progressive atrophy of the iris at the site of enclavation can also increase the risk for this complication. Reintervention with implantation of a new IOL is considered the best management option. Pupillary distortion or ovalization has been described and is related to excessively peripheral enclavation of the haptics. Schallenberg et al.2 found this complication in 32.0% of their patients after retropupillary implantation. Faria et al.13 described an incidence of 15.3%. Other studies with prepupillary IOLs did not report on this complication.9,29 Our study showed an incidence of 4.2% (1.8% with prepupillary IOLs and 7.9% with retropupillary IOLs), which is lower than that of other studies. We believe that pupillary distortion tends to be more frequent with retropupillary IOLs because of the impossibility of viewing the haptics during the procedure. Other potential complications described in the literature are vitreous prolapse, uveitis, and glaucoma,3,9,13 although we did not find any cases. The incidence of RD seems to be linked to the preoperative situation of the patients rather than to IOL implantation. Some authors do not report any cases,9,12 whereas others publish low incidences with both prepupillary IOLs29 (0.8%) and retropupillary IOLs2,3,13 (0.3% to 3.2%). We observed RD, a severe complication, in 3.5% of prepupillary IOLs and 2.6% of retropupillary IOLs, with no differences according to location. In conclusion, iris-claw IOL implantation, in both prepupillary and retropupillary locations, is a procedure that allows good visual rehabilitation in complex aphakic eyes. Although this study could not demonstrate the superiority of one location over the other, retropupillary implantation seemed to offer better visual results with lower loss of endothelial cells, as well as a lower incidence and later onset of CME. In our opinion, retropupillary implantation is simpler and displays the advantages of posterior chamber implantation, with few intraoperative and postoperative complications. The main limitations of this study were the retrospective design and dropouts during follow-up. Approximately 400 individuals should be enrolled to reach sufficient statistical power to detect differences between groups. Prospective multicenter studies, with a larger sample size, are deemed necessary to demonstrate superiority of one location over the other.
825
WHAT WAS KNOWN Iris-claw IOL fixation is an effective option in patients with absence of capsular support and, unlike AC IOLs and scleral-fixated PC IOLs, it seems to have fewer complications. Several studies have evaluated anterior chamber implantation and others have analyzed posterior chamber implantation, but few have compared both locations. Only 3 studies (one of them in penetrating keratoplasty) have compared the results of iris-claw IOL implantation considering its location. All of them have limitations: a low number of patients, short follow-up periods, and analysis of few parameters.
WHAT THIS PAPER ADDS Although the iris-claw IOL provided good visual outcomes with few complications regardless of location, prepupillary IOL implantation seemed to result in greater endothelial cell loss and earlier onset of CME than retropupillary IOL implantation. Given that patients who have this type of procedure are complex and might have other ocular pathologies, it is important to determine whether prepupillary or retropupillary implantation offers better results in the long term. The number of cases, the longer follow-up time, and the multiple parameters analyzed in this study contribute to clarifying this question.
REFERENCES 1. Worst JGF. Iris claw lens [letter]. Am Intra-Ocular Implant Soc J 1980; 6:166–167 2. Schallenberg M, Dekowski D, Hahn A, Laube T, Steuhl K-P, Meller D. Aphakia correction with retropupillary fixated iris-claw lens (Artisan) – long-term results. Clin Ophthalmol 2014; 8:137–141. Available at: https://www.ncbi .nlm.nih.gov/pmc/articles/PMC3878958/pdf/opth-8-137.pdf. Accessed May 16, 2018 3. Forlini M, Soliman W, Bratu A, Rossini P, Cavallini GM, Forlini C. Long-term follow up of retropupillary iris-claw intraocular lens implantation: a retrospective analysis. BMC Ophthalmol 2015; 15:143. Available at: https ://www.ncbi.nlm.nih.gov/pmc/articles/PMC4624704/pdf/12886_2015 _Article_146.pdf. Accessed May 16, 2018 €ell JL, Verdaguer P, Elies D, Gris O, Manero F, Mateu-Figueras G, 4. Gu Morral M. Secondary iris-claw anterior chamber lens implantation in patients with aphakia without capsular support. Br J Ophthalmol 2014; 98:658–663 5. Solomon K, Gussler JR, Gussler C, Van Meter WS. Incidence and management of complications of transsclerally sutured posterior chamber lenses. J Cataract Refract Surg 1993; 19:488–493 6. Sawada T, Kimura W, Kimura T, Suga H, Ohte A, Yamanishi S, Ohara T. Long-term follow-up of primary anterior chamber intraocular lens implantation. J Cataract Refract Surg 1998; 24:1515–1520 7. Wagoner MD, Cox TA, Ariyasu RG, Jacobs DS, Karp CL. Intraocular lens implantation in the absence of capsular support; a report by the American Academy of Ophthalmology (Ophthalmic Technology Assessment). Ophthalmology 2003; 110:840–859 8. Dick HB, Augustin AJ. Lens implant selection with absence of capsular support. Curr Opin Ophthalmol 2001; 12:47–57 9. Zheng D, Wan P, Liang J, Song T, Liu Y. Comparison of clinical outcomes between iris-fixated anterior chamber intraocular lenses and scleral-fixated posterior chamber intraocular lenses in Marfan syndrome with lens subluxation. Clin Exp Ophthalmol 2012; 40:268–274 10. Lett KS, Chaudhuri PR. Visual outcomes following Artisan aphakia iris claw lens implantation. Eye 2011; 25:73–76. Available at: http://www.nature .com/eye/journal/v25/n1/pdf/eye2010146a.pdf. Accessed May 16, 2018 11. Gicquel J-J, Guigou S, Bejjani RA, Briat B, Ellies P, Dighiero P. Ultrasound biomicroscopy study of the Verisyse aphakic intraocular lens combined with
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penetrating keratoplasty in pseudophakic bullous keratopathy. J Cataract Refract Surg 2007; 33:455–464 Hsing YE, Lee GA. Retropupillary iris claw intraocular lens for aphakia. Clin Exp Ophthalmol 2012; 40:849–854 Faria MY, Ferreira NP, Pinto JM, Sousa DC, Leal I, Neto E, MarquesNeves C. Retropupillary iris claw intraocular lens implantation in aphakia for dislocated intraocular lens. Int Med Case Rep J 2016; 9:261–265. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5010170/pdf/imc rj-9-261.pdf. Accessed May 16, 2018 € u €zen S, Oks €z H. Iris-claw intraocular lens implantation: Helvaci S, Demirdu anterior chamber versus retropupillary implantation. Indian J Ophthalmol 2016; 64:45–49. Available at: https://www.ncbi.nlm.nih.gov/pmc/articles /PMC4821121/?reportZprintable. Accessed May 16, 2018 Rijneveld WJ, Beekhuis WH, Hassman EF, Dellaert MMMJD, Gerrards AJM. Iris claw lens: Anterior and posterior iris surface fixation in the absence of capsular support during penetrating keratoplasty. J Refract Corneal Surg 1994; 10:14–19 Labeille E, Burillon C, Cornut P-L. Pars plana vitrectomy combined with irisclaw intraocular lens implantation for lens nucleus and intraocular lens dislocation. J Cataract Refract Surg 2014; 40:1488–1497 Menezo JL, Martinez MC, Cisneros AL. Iris-fixated Worst claw versus sulcus-fixated posterior chamber lenses in the absence of capsular support. J Cataract Refract Surg 1996; 22:1476–1484 zquez M, Gris O, Manero F. Secondary €ell JL, Velasco F, Malecaze F, Va Gu Artisan–Verysise aphakic lens implantation. J Cataract Refract Surg 2005; 31:2266–2271. Available at: https://www.jcrsjournal.org/article/S0886-33 50(05)00798-4/pdf. Accessed May 16, 2018 Chen Y, Liu Q, Xue C, Huang Z, Chen Y. Three-year follow-up of secondary anterior iris fixation of an aphakic intraocular lens to correct aphakia. J Cataract Refract Surg 2012; 38:1595–1601 Ye P, He F, Shi J, Liu J, Liang G, Wu J, Xu W. Artisan iris-fixated intraocular lens implantation in combination with pupilloplasty–correction of aphakia with pathologically large pupil and insufficient capsular support. Can J Ophthalmol 2017; 52:155–160 Riazi M, Moghimi S, Najmi Z, Ghaffari R. Secondary Artisan–Verysise intraocular lens implantation for aphakic correction in post-traumatic vitrectomized eye. Eye 2008; 22:1419–1424. Available at: http://www.nature.com /eye/journal/v22/n11/pdf/eye2008271a.pdf. Accessed May 16, 2018 Acar N, Kapran Z, Altan T, Kucuksumer Y, Unver YB, Polat E. Secondary iris claw intraocular lens implantation for the correction of aphakia after pars plana vitrectomy. Retina 2010; 30:131–139 Shajari M, Scheffel M, Koss MJ, Kohnen T. Dependency of endothelial cell loss on anterior chamber depth within first 4 years after implantation of irissupported phakic intraocular lenses to treat high myopia. J Cataract Refract Surg 2016; 42:1562–1569
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24. Gonnermann J, Amiri S, Klamann M, Maier A-KB, Joussen AM, Rieck PW, Torun N, Bertelmann E. Endothelzellverlust nach retropupillar fixierter Irisklauen-Linse [Endothelial cell loss after retropupillary iris-claw intraocular lens implantation]. Klin Monbl Augenheilkd 2014; 231:784–787 25. Anbari A, Lake DB. Posteriorly enclavated iris claw intraocular lens for aphakia: long-term corneal endothelial safety study. Eur J Ophthalmol 2015; 25:208–213 26. Ganesh S, Brar S, Relekar K. Long term clinical and visual outcomes of retrofixated iris claw lenses implantation in complicated cases. Open Ophthalmol J 2016; 10:111–118. Available at: https://www.ncbi.nlm.nih.gov/pmc /articles/PMC4899510/pdf/TOOPHTJ-10-111.pdf. Accessed May 16, 2018 Sabala27. Anglada-Escalona R, Castellví-Manent J, Parera-Arranz MA, Llopart A. Inverted implantation of posterior iris fixated intraocular lens with 23G transconjunctival vitrectomy in the management of secondary implantTechnique and stability, astigmatism and endothelial loss outcomes. J Emmetropia 2014; 5:133–143. Available at: http://www.journalofemmet ropia.org/numeros/pdf/5-3/Journal-article-3.pdf. Accessed May 16, 2018 € Posterior iris fixation of the iris28. Baykara M, Ozcetin H, Yilmaz S, Timuc¸in OB. claw intraocular lens implantation through a scleral tunnel incision. Am J Ophthalmol 2007; 144:586–591 29. De Silva SR, Arun K, Anandan M, Glover N, Patel CK, Rosen P. Iris-claw intraocular lenses to correct aphakia in the absence of capsule support. J Cataract Refract Surg 2011; 37:1667–1672 OTHER CITED MATERIAL A. Ophtec BV. Artisan Aphakia model 205. Available at: https://www.ophtec .com/products/cataract-surgery/iols/artisan-aphakia. Accessed May 16, 2018.
Disclosures: None of the authors has a financial or proprietary interest in any material or method mentioned.
First author:
~o Peralba, MD, PhD Rosario Tourin Cornea and Ocular Surface Unit, Ophthalmology Department, Complejo Hospitalario Universitario de Santiago de Compostela, Santiago de Compostela, Spain