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Surgical outcomes and complications of sutured scleral fixated intraocular lenses in pediatric eyes
Surgical outcomes and complications of sutured scleral fixated intraocular lenses in pediatric eyes Parveen Sen, MS, Vinay Kumar S., MD, Pramod Bhende, MS, Pukhraj Rishi, MS, Ekta Rishi, MS, Chetan Rao, MS, Dhanashree Ratra, MS, Pradeep Susvar, MS, Sreelakshmi Kummamuri, MS, Sufiyan Shaikh, MS, Lingam Gopal, MS, FRCS ABSTRACT ● Objective: To study the outcome and complications of sutured scleral fixated intraocular lenses (SSFIOL) in children. Design: Retrospective study. Subjects: A total of 279 eyes of 230 children who underwent SSFIOL at ≤18 years of age in a tertiary eye care centre in India. Methods: Treatment-naive children having traumatic cataract or subluxated lens underwent a single-sitting lensectomy and pars plana vitrectomy (PPV), along with SSFIOL insertion. Children with aphakia underwent PPV with SSFIOL, and vitrectomized eyes underwent only SSFIOL implantation. Fixation of SSFIOL was done by the 4-point ab externo fixation technique using 10-0 prolene suture. Main outcome measures: Preoperative and postoperative visual acuity, as well as intraoperative and postoperative complications. Results: The mean age at which SSFIOL was performed was 10.8 ± 4.22 years. The most common indication of SSFIOL in our study was traumatic subluxation of lens (47.63%; n ¼ 133 patients), followed by congenital subluxation in 38.7% (n ¼ 108). Bestcorrected visual acuity was maintained or improved from the preoperative visual acuity in 93.19% of eyes. The complications included choroidal detachment in 2.86% (n ¼ 8), dispersed vitreous hemorrhage in 2.86% (n ¼ 8), endophthalmitis in 0.72% (n ¼ 2), raised intraocular pressure in 12.54% (n ¼ 35), diplopia in 0.72% (n ¼ 2), retinal detachment in 5.73% (n ¼ 16), and dislocation of the SSFIOL in 4.6% (n ¼ 13). The mean follow-up after SSFIOL implantation was 39.68 months. Conclusions: SSFIOLs are effective in correcting aphakia in children; long-term follow-up of these children is, however, necessary.
Transscleral sulcus fixation of the posterior chamber intraocular lens (IOL) was first described by Girard in 19811 and later modified by Malbran et al.2 in aphakic eyes after intracapsular cataract extraction in 1986. It is very important to treat early in unilateral aphakia in children because they are at high risk of developing amblyopia. However, treatment options for aphakia in the absence of capsular support are limited. Spectacles in unilateral aphakia may result in diplopia and loss of binocularity due to aniseikonia. Contact lens is currently the most accepted method to correct aphakia in children. Lenses are noninvasive and provide acceptable quality of refraction. However, their use entails constant vigilance to ensure compliance and avoid contact lens related complications.3 The cost of quality care and maintenance is often beyond the means of many households and, in a predominantly agrarian society, carries an added risk of infection. Sutured scleral fixated intraocular lens (SSFIOL) is theoretically a better option because the IOL sits in the original anatomical position behind the iris plane. SSFIOL scores over anterior chamber IOL (ACIOL) with regard to associated complications such as corneal endothelial damage, chronic anterior chamber inflammation, and cystoid macular edema.4,5 Moreover, ACIOL and iris-fixated IOL may not be possible in cases of trauma where healthy iris
tissue support may be inadequate. The SSFIOL implantation technique, despite its distinct advantages, is also associated with complications such as retinal detachment (RD), vitreous hemorrhage, choroidal hemorrhage, endophthalmitis, suture erosion, and SSFIOL dislocation.6,7 Although studies have shown the efficacy and complications of SSFIOL in an adult population,8 similar studies in large populations are limited in younger age groups. Our study analyses the outcome of SSFIOL in a large group of patients, with a wide range of indications, age r18 years at SSFIOL implantation.
PATIENTS
AND
METHODS
A retrospective observational study of pediatric patients age r18 years who underwent SSFIOL with pars plana vitrectomy (PPV) from 2000 to 2014 at a tertiary eye care centre in India was undertaken, and children with a minimum of 6 weeks of follow-up were included. A trial of glasses or contact lens was given for aphakic children before SSFIOL implantation was considered. The study revealed 279 eyes of 230 patients who underwent SSFIOL implantation. The study was performed after approval was obtained from the institutional review board and ethics committee. All study procedures conformed to the tenets
& 2017 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jcjo.2017.07.015 ISSN 0008-4182/17 CAN J OPHTHALMOL — VOL. ], NO. ], ] 2017
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Outcomes and complications of SSFIOL in pediatric eyes—Sen et al. of the Declaration of Helsinki for research involving human subjects. Informed consent for the surgical procedure was obtained from all parents or guardians of patients included in the study. All patients had detailed evaluations preoperatively and postoperatively. Parameters recorded at baseline, 6 weeks postsurgery, 1 year, and at final follow-up included demographic variables, best-corrected visual acuity (BCVA; measured on a Snellen chart and converted to logMAR units for analysis), refractive error including spherical equivalent, slit-lamp examination, intraocular pressure (IOP) measurement by Goldmann applanation tonometry, fundus examination by indirect ophthalmoscopy, and postoperative complications. Treatment-naive patients having traumatic cataract or subluxated lens underwent a single-sitting lensectomy and PPV, along with SSFIOL insertion. Patients with aphakia after cataract surgery without capsular support underwent PPV with SSFIOL, and only SSFIOL implantation was done in those with previously vitrectomized eyes. IOL power was calculated using the SRK-II formula. Keratometry and axial length measurements were done preoperatively, except in uncooperative or very young children, for whom the measurement was taken intraoperatively. In cases where the corneal surface was too irregular for keratometry, corneal topography was performed, and the Sim K value was determined. In the postoperative period, unilateral cases were treated for amblyopia by patching after the surgery as required. Postoperative complications were managed appropriately. Surgical Technique
Experienced vitreoretinal surgeons performed all surgeries. Three-port PPV was completed with meticulous
peripheral vitreous dissection, especially in the horizontal meridians where the SSFIOL (PMMA posterior chamber IOL with 2 eyelets, Hanita lenses) was to be anchored. Fixation of SSFIOL was done using 10-0 prolene suture (Ethicon STC6, PR, USA) and a 2-knot 4-point ab externo fixation technique, as described by Rao et al.,9 in all eyes (Fig. 1). A corneal marker was used to ensure accurate placement of the scleral flaps. The rail road technique was used for passing the sutures, and the direction of sutures though the eyelets was changed to neutralize the torque exerted. The knots were buried by rotating them into the eyeball. Scleral flaps and corneoscleral section were secured with 10-0 ethilon suture (Ethicon, PR, USA). Outcome Measures
Preoperative and postoperative visual acuity, refractive outcome, and intraoperative and postoperative complications were the principal outcome measures studied. Statistical Analysis
SPSS 14.0 software (IBM SPSS Statistics, IBM Corporation, Chicago, IL, USA) was used for statistical analysis. Fisher’s exact test with 2-tailed p-values was used for categorical data, and paired and unpaired t tests were used for continuous data. A p-value of 0.05 or less was considered to be statistically significant.
RESULTS Our study included 279 eyes of 230 patients who underwent SSFIOL implantation at age ≤18 years. Of the patients, 74.3% (n ¼ 171) were male and 25.7% (n ¼ 59) were female. The mean age at which SSFIOL was
Fig. 1 — Illustration of the standardized sutured scleral fixated intraocular lenses (SSFIOL) implantation technique.
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Outcomes and complications of SSFIOL in pediatric eyes—Sen et al. implanted was 10.8 ± 4.22 years (range 3.5–18 years). Unilateral SSFIOL implantation was done in 78.7% (n ¼ 181) of patients, and 21.3% (n ¼ 49) had bilateral SSFIOL implantation. The most common indication for SSFIOL implantation in our study was traumatic subluxation of lens in 47.63% (n ¼ 133) of eyes, followed by congenital subluxation in 38.71% (n ¼ 108) of eyes, dislocated IOL in 5.8% (n ¼ 16) of eyes, aphakia after cataract surgery with no capsular support in 3.9% (n ¼ 11) of eyes, and aphakia secondary to previous vitreoretinal surgery in 3.9% (n ¼ 11) of eyes. Primary SSFIOL implantation was done in 71.3% (n ¼ 199), and 28.7% (n ¼ 80) of eyes had aphakia/pseudophakia with previous lens extraction. The mean follow-up after SSFIOL was 39.68 months; 141 eyes (50.5%) had more than 12 months of follow-up, with a mean of 75.48 ± 43.44 months; 84 eyes (30.1%) had more than 60 months of follow-up, with a mean of 104.03 ± 31.86 months; and 26 eyes (9.3%) had more than 120 months of follow-up, with a mean of 143.92 ± 13.56 months. Visual Outcome
Mean BCVA values for preoperative and all postoperative visits are given in Table 1. BCVA in 93.19% eyes was maintained or improved from preoperative visual acuity. Figure 2 shows the comparison between preoperative visual acuity and 6-week postoperative visual acuity. A decrease in visual acuity at the last follow-up visit was seen in 19 eyes (6.8%). The causes for the decrease in vision in these eyes were RD and its sequelae in 7 of 19 eyes, raised IOP in 4 of 19 eyes, amblyopia in 7 of 19 eyes, and atypical retinitis pigmentosa in 1 eye. Spherical error, cylindrical error, and spherical equivalent values for each visit are given in Table 1. There was a significant myopic shift in refraction when refraction at 1 year and last followup visit were compared with refraction 6 weeks postoperatively (Fig. 3). Postoperative Complications and Interventions
Complications included serous choroidal detachment in 2.86% (n ¼ 8), dispersed vitreous hemorrhage in 2.86% (n ¼ 8), endophthalmitis in 0.72% (n ¼ 2), diplopia in 0.72% (n ¼ 2), RD in 5.73% (n ¼ 16), and dislocation of the SSFIOL in 4.7% (n ¼ 13). Raised IOP requiring antiglaucoma medication was seen in 35 (12.54%)
patients in the postoperative period. Diode cyclophotocoagulation was required in 7 (2.5%) cases. Early complications noted in the immediate postoperative period include dispersed vitreous hemorrhage and serous choroidal detachment, which resolved spontaneously. Raised IOP requiring antiglaucoma medication was seen in 35 (12.54%) eyes. Whereas 20 of 279 (7.2%) eyes had pre-existing raised IOP, 15 of 279 (5.4%) eyes developed raised IOP within 4–6 weeks after surgery. In 13 of 15 (86.7%) eyes, the increase in IOP was well controlled with topical antiglaucoma medication. Only 2 (13.3%) eyes required diode or endo cyclophotocoagulation to control IOP. Endophthalmitis was seen in 2 patients. One patient underwent SSFIOL with trabeculectomy. He presented 4 months after surgery with blebitis as well as hypopyon and vitreous exudates. He responded well to topical and intravitreal antibiotics. The second patient had a traumatic subluxation of the lens, for which he underwent primary SSFIOL implantation. The patient developed anterior chamber reaction by the 11th postoperative day. The endophthalmitis was controlled with intravitreal antibiotics. None of the cases developed endophthalmitis related to SSFIOL suture exposure. Long-term complications included RD and IOL dislocation. The incidence of RD in our study was 5.73%. The interval between SSFIOL surgery and occurrence of RD varied from as early as postoperative day 6 to a maximum of 7 years. About one third of the patients (6 of 16 eyes) had RD within 6 weeks after SSFIOL surgery. PVR changes were found in 50% of eyes (8 of 16 eyes). The retina remained attached until the final follow-up after single RD surgery in 11 of 16 eyes (68.75%), and anatomical success was achieved in 3 of 16 eyes (18.75%) after a second surgery. Overall, the retina was successfully reattached in 87.5% of eyes (14 of 16). Two patients had recurrent RD and severe PVR changes with optic atrophy despite multiple surgeries. Visual acuity was maintained or showed improvement in 7 of 16 (43.75%) eyes at the final visit. Eight of 16 eyes had a history of penetrating or blunt trauma, and 2 of these patients had Marfan’s syndrome. IOL dislocation was seen in 13 eyes after a mean duration of 110.3 (range 68–159) months after surgery. A history of minor trauma before dislocation could be elicited in 2 cases. All other children had a sudden spontaneous dislocation. The mean age of patients with
Table 1—BCVA values, spherical error, cylindrical error, and spherical equivalent for all eyes
BCVA p-Value (paired t test) Sphere Cylinder Spherical equivalent p-Value (paired t test)
Preoperative
6 Weeks Postoperative
1 Year Postoperative
Last Follow-Up Visit
1.29 ± 0.80
0.66 ± 0.59 o0.0001 −0.50 ± 2.27 −1.78 ± 1.67 −1.40 ± 2.10
0.55 ± 0.53 o0.0001 −0.92 ± 2.09 −1.85 ± 1.26 −1.80 ± 2.09 0.0205
0.54 ± 0.63 o0.0001 −1.97 ± 3.64 −1.86 ± 1.39 −2.90 ± 3.68 ≤0.001
þ4.15 ± 11.01 −1.31 ± 1.90 þ3.50 ± 11.36
For p-value, postoperative best-corrected visual acuities (BCVAs) were compared with preoperative BCVA, and first year and last follow-up spherical equivalents were compared with sixth week spherical equivalent.
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Outcomes and complications of SSFIOL in pediatric eyes—Sen et al.
Fig. 2 — Scattergram of BCVA in 279 eyes that underwent implantation of SSFIOL. The correlation between pre- and postoperative visual acuity at the sixth week of follow-up is illustrated. Visual acuity is represented in logMAR values. BCVA, best-corrected visual acuity; SSFIOL, sutured scleral fixated intraocular lens.
dislocation at SSFIOL implantation was 10.66 ± 4.67 years, and the mean age of patients without dislocation was 10.8 ± 4.21 years (p ¼ 0.528). The average follow-up was 133.67 ± 30.87 months in patients with dislocation and 35.09 ± 43.39 months in those without dislocation was (p ¼ 0.001). The dislocated IOL was successfully refixated surgically in all these cases. Table 2 illustrates the complications observed in this case series.
DISCUSSION In children, SSFIOL not only serves the purpose of visual rehabilitation but also protects against amblyopia. The current study is one of the largest series of pediatric sutured scleral fixated IOLs, with 279 eyes and an average follow-up of 39.68 months. The youngest child in our study was 3.5 years old, though this procedure has been described for children aged o3 years as well.10
Improvement or stabilization in BCVA was seen in 93.19% of eyes, with maximal improvement seen within the first 6 weeks of surgery. In contrast to a contact lens, which can be used for a maximum of 12 waking hours and must be placed and removed every day, an SSFIOL is continuously present in visual axis, at a position very close to the anatomical location of the natural crystalline lens, resulting in a focused image all the time. This, we believe, is the major advantage of an SSFIOL. A trend toward myopic refraction was seen, as demonstrated by Table 1 and Figure 3. This could be attributed to the increase in axial length of the eyes with increasing age of the children. Other authors have described this as well.11 Vitreous hemorrhage is a common complication12 because the needle for SSFIOL passes through extremely vascular uveal tissue. In our study, less than 3% had dispersed vitreous hemorrhage, which cleared spontaneously in all cases. We believe that having an infusion
Fig. 3 — Vertical bar diagram depicting the distribution of SE after surgery at 6 weeks, 1 year, and at final visit. SSFIOL, sutured scleral fixated intraocular lens; SE, spherical equivalent.
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Outcomes and complications of SSFIOL in pediatric eyes—Sen et al. Table 2—Table showing the postoperative complications, rate and timing of development, and management Complication IOL dislocation Retinal detachment Raised IOP Choroidal detachment Dispersed VH Endophthalmitis Diplopia
Rate, % (n) 4.65 5.73 12.54 2.86 2.86 0.72 0.72
(13) (16) (35) (8) (8) (2) (2)
Mean Duration from Surgery
Range
Management
110.38 ± 25.9 months (9.1 years) 23.54 months 3.09 ± 2.38 weeks 2.62 ± 1.76 days POD 1 4 months, 11th POD 6 weeks
68–159 months POD 6–7 years 1–6 weeks 1–6 days POD 1 11 days–4 months 6 weeks
Refixation of IOL Surgical Medical management in 28, diode CPC in 7 Topical steroids in 7, systemic steroids in 1 patient Conservative Topical þ intravitreal antibiotics Prisms
IOL, intraocular lens; IOP, intraocular pressure; diode CPC, diode cyclophotocoagulation; POD, postoperative day.
cannula in situ throughout the surgical procedure helps to maintain a pressurized globe, thus avoiding this problem. This has also been suggested by Por and Lavin.13 Choroidal detachment seen in our cases was secondary to transient hypotony and resolved with steroids. Vitrectomy, done through the pars plana route in this series of cases, allows the surgeon to meticulously remove peripheral vitreous as well as any capsular remnants before passing the sutures. This reduces the incidence of suture/ haptic entanglement intraoperatively. This also reduces the metabolic activity around the suture. It has been well documented that suture disintegration is maximal at the point where it crosses through highly vascular tissue. Complete PPV before SSFIOL also reduces the long-term risk of RD.14 However, these techniques require the surgery to be performed by experienced vitreoretinal surgeons. We saw RD in 16 out of 279 eyes (5.73%). Of the eyes that developed RD after surgery for SSFIOL, congenital subluxation was seen in 8 eyes (50%) and history of trauma was present in 8 eyes (20%). In as much as trauma and Marfan’s syndrome by themselves are independent risk factors for RD, the percentage of risk that can be attributed to SSFIOL implantation in this subgroup needs to be determined.15 A successful anatomical outcome was
achieved in 87.5% of eyes with an average of 1.43 surgeries (range 1–3) per eye. In a series of 122 eyes in adult cases, Lee et al.16 found RD in 4.9% with a followup of up to 42 months. Asadi and Kheirkhah12 reported a 4% prevalence of RD in patients undergoing SSFIOL with an average follow-up of 3 years. The retinal detachment rate of 5.73% in this case series is comparable. Late endophthalmitis after scleral fixation of IOL has been reported in the literature.17,18 The ab externo technique of scleral fixation was used in all our patients. The knots were not only rotated within the globe but also covered by a partial-thickness scleral flap that was sutured, thereby reducing chances of suture tract–related endophthalmitis.19,20 Whenever it was not possible to rotate the knot inside, longer suture ends were taken and care was taken to cover them by the scleral flaps, which were sutured. None of the cases in our series had late endophthalmitis secondary to knot exposure. Trabeculectomy bleb and infection at the site of wound repair were the source of infection in the 2 eyes that did develop endophthalmitis in this case series. There was no suture erosion or suture-related endophthalmitis in either of these cases. Degradation of polypropylene sutures with time has been well documented in the literature. Jongebloed and
Fig. 4 — Graph showing rate and temporal distribution of complications. 1, endophthalmitis; 2, choroidal detachment; 3, vitreous hemorrhage; 4, raised intraocular pressure; 5, retinal detachment; 6, intraocular lens dislocation. CAN J OPHTHALMOL — VOL. ], NO. ], ] 2017
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Outcomes and complications of SSFIOL in pediatric eyes—Sen et al. Table 3—Comparison of SSFIOL characteristics and complications of this study with previous published literature
Author
Year
Eyes, n
Mean f/u (months)
Kumar et al.22 Zetterström et al.23 Ozmen et al.24 Buckley11 Sewelam25 Bardorf et al.26 Asadi and Kheirkhah12 Burcu et al.27 Current study
1999 1999 2002 2007 2003 2004 2008 2014 2015
11 21 21 33 20 43 25 24 279
10.9 20 22.5 61 19.35 37 81 6 40
Mean Age at SSFIOL,years
Gain/Stable in BCVA, % (n)
6.4 5.8
81.7 (8) 100 (21)
9.7 7.7 10 6.6 11.5 10.8
Complications
81 40 100 48 100 93.19
(27) (8) (43) (12) (24) (260)
1, % (n)
2, % (n)
3, % (n)
4,% (n)
5,% (n)
6,% (n)
7, % (n)
0 0 0 9 (3) 0 0 24 (6) 0 4.65 (13)
0 0 4.7 (1) 0 0 0 4 (1) 0 5.73 (16)
9.09 (1) 0 0 6 (2) 0 5 (2) 0 12.5 (3) 12.54 (35)
0 0 0 3 (1) 0 5 (2) 52 (13) 0 2.86 (8)
0 0 0 0 0 2 (1) 8 (2) 0 2.86 (8)
0 0 4.7 (1) 0 0 0 4 (1) 4.2 (1) 0.72 (2)
18.18 (2) 0 0 0 0 0 0 0
n, number of eyes; f/u, follow-up; SSFIOL, sutured scleral fixated intraocular lens; BCVA, best-corrected visual acuity; 1, intraocular lens dislocation; 2, retinal detachment; 3, raised intraocular pressure; 4, vitreous hemorrhage; 5, choroidal detachment; 6, endophthalmitis; 7, suture exposure.
Worst21 studied a 10-0 polypropylene suture that they had used as a fixation suture for an IOL for a period of 6.5 years. They observed that the suture showed cracks perpendicular to the longitudinal axis of the suture; part of the surface layer was nearly detached or completely missing, and the diameter of the suture was decreased by over 50% in comparison with the original diameter.20 This degradation is considered to be caused by the enzymatic action of ocular fluids. The mean time to dislocation of IOL in our series of cases was 9.2 years. A similar study by Vote et al.6 had a mean time to dislocation of 4 years and that by Buckley11 was 102 months. Vote et al.6 reported dislocations of IOL in 27.9% of cases. Asadi and Kheirkhah12 had a dislocation rate of 24% 7–10 years after surgery. The fixation technique used by Asadi and Kheirkhah12 was 2-point ab externo fixation, whereas we used the 4-point fixation in all cases. Furthermore, in the technique we used to fixate the SSFIOL, there are no intraocular knots. Compared with a conventional 4-knot technique, 2 knots near the 2 haptics of the IOL and 2 knots to fix over the sclera, the technique we used requires only 2 scleral fixating knots as the suture goes through the eyelets of the IOL without any cut ends intraocularly. Because enzymatic activity of tissue fluids causes suture degradation, a meticulous vitrectomy from the area of IOL fixation might have improved the stability of the IOL and reduced the chance of suture breakage, resulting in a dislocation rate of 4.65% in our study. These rates may increase with long-term follow-up in these eyes. Prolene suture degradation is an expected natural event, and fibrosis has not been demonstrated to occur around the haptics. Thus, the SSFIOL is anchored only by means of a degradable suture material. The life span of the 10-0 Prolene remains to be determined, and the risk factors that cause early dissolution in some patients while keeping the suture intact in the rest remain unknown. It is also imperative to identify other suture materials with a longer life span. In addition to suture degradation, risk factors for suture breakage in children could include increase in the size of the eyeball and an increased risk of trauma to the eyeball. Despite the
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dislocation, in all cases of dislocated IOLs, there was neither damage to the retina nor any associated complication, and refixation of the IOL resulted in good visual acuity in all cases. Also, for the time that the IOL was in place it was an effective means of refractive correction, which is particularly important in the pediatric age group. Figure 4 demonstrates the distribution of complications over the follow-up period. Table 3 compares our results with previous published reports on pediatric SSFIOLs. Limitations of the Study
Although our study gives the outcome of PPV with SSFIOL in a large series of pediatric eyes, it is limited by its retrospective nature as well as the absence of randomized comparative data. In addition, for complications like IOL dislocation, longer follow-up may be necessary.
CONCLUSIONS We believe that the continuous presence of IOL in the visual axis in a child’s visual formative years may well play an important role in preventing amblyopia, a very important cause of loss of vision in childhood aphakia. A decrease in visual acuity was observed in 6.81% of eyes in the postoperative period. Retinal detachment can pose a serious threat to vision in these eyes. Furthermore, the complications of RD and IOL dislocations can occur months after the initial surgery. Hence, need for long-term follow-up and education of parents regarding these possible complications cannot be overemphasized. REFERENCES 1. Girard L. Pars plana phaco prosthesis (aphakic intraocular implant): a preliminary report. Ophthalmic Surg. 1981;12:19-22. 2. Malbran ES, Malbran E Jr, Negri I. Lens guide suture for transport and fixation in secondary IOL implantation after intracapsular extraction. Int Ophthalmol. 1986;9:151-60. 3. Stamler JF. The complications of contact lens wear. Curr Opin Ophthalmol. 1998;9:66-71. 4. Kwong YY, Yuen HK, Lam RF, et al. Comparison of outcomes of primary scleral-fixated versus primary anterior chamber intraocular lens implantation in complicated cataract surgeries. Ophthalmology. 2007;114:80-5.
Outcomes and complications of SSFIOL in pediatric eyes—Sen et al. 5. Yen KG, Reddy AK, Weikert MP, et al. Iris fixated posterior chamber intraocular lenses in children. Am J Ophthalmol. 2009;147: 121-6. 6. Vote BJ, Tranos P, Bunce C, et al. Long-term outcome of combined pars plana vitrectomy and scleral fixated sutured posterior chamber intraocular lens implantation. Am J Ophthalmol. 2006;141:308-12. 7. McAllister AS, Hirst LW. Visual outcomes and complications of scleral-fixated posterior chamber intraocular lenses. J Cataract Refract Surg. 2011;37:1263-9. 8. Kjeka O, Bohnstedt J, Meberg K, Seland JH. Implantation of scleral-fixated posterior chamber intraocular lenses in adults. Acta Ophthalmol. 2008;86:537-42. 9. Rao SK, Gopal L, Fogla R, et al. Ab externo 4-point scleral fixation. J Cataract Refract Surg. 2000;26:9-10. 10. Mittelviefhaus H, Mittelviefhaus K, Gerling J. Transscleral suture fixation of posterior chamber intraocular lenses in children under 3 years. Graefes Arch Clin Exp Ophthalmol. 2000;238:143-8. 11. Buckley EG. Hanging by a thread: the long-term efficacy and safety of transscleral sutured intraocular lenses in children (an American Ophthalmological Society thesis). Trans Am Ophthalmol Soc. 2007;105:294-311. 12. Asadi R, Kheirkhah A. Long-term results of scleral fixation of posterior chamber intraocular lenses in children. Ophthalmology. 2008;115:67-72. 13. Por YM, Lavin MJ. Techniques of intraocular lens suspension in the absence of capsular/zonular support. Surv Ophthalmol. 2005;50: 429-62. 14. Johnston RL, Charteris DG, Horgan SE, Cooling RJ. Combined pars plana vitrectomy and sutured posterior chamber implant. Arch Ophthalmol. 2000;118:905-10. 15. Sharma T, Gopal L, Shanmugam MP, et al. Retinal detachment in Marfan syndrome: clinical characteristics and surgical outcome. Retina. 2002;22:423-8. 16. Lee VY, Yuen HK, Kwok AK. Comparison of outcomes of primary and secondary implantation of scleral fixated posterior chamber intraocular lens. Br J Ophthalmol. 2003;87:1459-62. 17. Heilskov T, Joondeph BC, Olsen KR, et al. Late endophthalmitis after transscleral fixation of a posterior chamber intraocular lens. Arch Ophthalmol. 1989;107:1427. 18. Kang HM, Chung EJ. Late-onset Citrobacter koseri endophthalmitis with suture exposure after secondary intraocular lens implantation. Korean J Ophthalmol. 2011;25:285-8. 19. Baykara M, Avci R. Prevention of suture knot exposure in posterior chamber intraocular lens implantation by 4-point scleral
20. 21. 22. 23. 24. 25. 26. 27.
fixation technique. Ophthalmic Surg Lasers Imaging. 2004;35: 379-82. Van Meter WS. Long-term safety of polypropylene knots under scleral flaps for transsclerally sutured posterior chamber lenses. Trans Am Ophthalmol Soc. 1997;95:307-21. discussion 321–7. Jongebloed WL, Worst JF. Degradation of polypropylene in the human eye: a SEM-study. Doc Ophthalmol. 1986;64:143-52. Kumar M, Arora R, Sanga L, Sota LD. Scleral-fixated intraocular lens implantation in unilateral aphakic children. Ophthalmology. 1999;106:2184-9. Zetterström C, Lundvall A, Weeber H Jr, Jeeves M. Sulcus fixation without capsular support in children. J Cataract Refract Surg. 1999;25:776-81. Ozmen AT, Dogru M, Erturk H, Ozcetin H. Transsclerally fixated intraocular lenses in children. Ophthalmic Surg Lasers. 2002;33:394-9. Sewelam A. Four-point fixation of posterior chamber intraocular lenses in children with unilateral aphakia. J Cataract Refract Surg. 2003;29:294-300. Bardorf CM, Epley KD, Lueder GT, Tychsen L. Pediatric transscleral sutured intraocular lenses: efficacy and safety in 43 eyes followed an average of 3 years. J AAPOS. 2004;8:318-24. Burcu A, Yalniz-Akkaya Z, Abay I, Acar MA, Ornek F. Scleralfixated posterior chamber intraocular lens implantation in pediatric and adult patients. Semin Ophthalmol. 2014;29:39-44.
Footnotes and Disclosure: The authors have no proprietary or commercial interest in any material discussed in this article. The authors thank Mr. Vishwanathan for statistical analysis of data. From the Shri Bhagwan Mahavir Vitreoretinal Services, Sankara Nethralaya, Chennai, India. Originally received Apr. 11, 2017. Final revision Jul. 8, 2017. Accepted Jul. 19, 2017. Correspondence to Parveen Sen, MS, Sankara Nethralaya, 18 College Road, Nungambakkam, Chennai 600006, Tamil Nadu, India; [email protected]
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Transscleral sulcus fixation of the posterior chamber intraocular lens (IOL) was first described by Girard in 19811 and later modified by Malbran et al.2 in aphakic eyes after intracapsular cataract extraction in 1986. It is very important to treat early in unilateral aphakia in children because they are at high risk of developing amblyopia. However, treatment options for aphakia in the absence of capsular support are limited. Spectacles in unilateral aphakia may result in diplopia and loss of binocularity due to aniseikonia. Contact lens is currently the most accepted method to correct aphakia in children. Lenses are noninvasive and provide acceptable quality of refraction. However, their use entails constant vigilance to ensure compliance and avoid contact lens related complications.3 The cost of quality care and maintenance is often beyond the means of many households and, in a predominantly agrarian society, carries an added risk of infection. Sutured scleral fixated intraocular lens (SSFIOL) is theoretically a better option because the IOL sits in the original anatomical position behind the iris plane. SSFIOL scores over anterior chamber IOL (ACIOL) with regard to associated complications such as corneal endothelial damage, chronic anterior chamber inflammation, and cystoid macular edema.4,5 Moreover, ACIOL and iris-fixated IOL may not be possible in cases of trauma where healthy iris
tissue support may be inadequate. The SSFIOL implantation technique, despite its distinct advantages, is also associated with complications such as retinal detachment (RD), vitreous hemorrhage, choroidal hemorrhage, endophthalmitis, suture erosion, and SSFIOL dislocation.6,7 Although studies have shown the efficacy and complications of SSFIOL in an adult population,8 similar studies in large populations are limited in younger age groups. Our study analyses the outcome of SSFIOL in a large group of patients, with a wide range of indications, age r18 years at SSFIOL implantation.
PATIENTS
AND
METHODS
A retrospective observational study of pediatric patients age r18 years who underwent SSFIOL with pars plana vitrectomy (PPV) from 2000 to 2014 at a tertiary eye care centre in India was undertaken, and children with a minimum of 6 weeks of follow-up were included. A trial of glasses or contact lens was given for aphakic children before SSFIOL implantation was considered. The study revealed 279 eyes of 230 patients who underwent SSFIOL implantation. The study was performed after approval was obtained from the institutional review board and ethics committee. All study procedures conformed to the tenets
& 2017 Canadian Ophthalmological Society. Published by Elsevier Inc. All rights reserved. http://dx.doi.org/10.1016/j.jcjo.2017.07.015 ISSN 0008-4182/17 CAN J OPHTHALMOL — VOL. ], NO. ], ] 2017
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Outcomes and complications of SSFIOL in pediatric eyes—Sen et al. of the Declaration of Helsinki for research involving human subjects. Informed consent for the surgical procedure was obtained from all parents or guardians of patients included in the study. All patients had detailed evaluations preoperatively and postoperatively. Parameters recorded at baseline, 6 weeks postsurgery, 1 year, and at final follow-up included demographic variables, best-corrected visual acuity (BCVA; measured on a Snellen chart and converted to logMAR units for analysis), refractive error including spherical equivalent, slit-lamp examination, intraocular pressure (IOP) measurement by Goldmann applanation tonometry, fundus examination by indirect ophthalmoscopy, and postoperative complications. Treatment-naive patients having traumatic cataract or subluxated lens underwent a single-sitting lensectomy and PPV, along with SSFIOL insertion. Patients with aphakia after cataract surgery without capsular support underwent PPV with SSFIOL, and only SSFIOL implantation was done in those with previously vitrectomized eyes. IOL power was calculated using the SRK-II formula. Keratometry and axial length measurements were done preoperatively, except in uncooperative or very young children, for whom the measurement was taken intraoperatively. In cases where the corneal surface was too irregular for keratometry, corneal topography was performed, and the Sim K value was determined. In the postoperative period, unilateral cases were treated for amblyopia by patching after the surgery as required. Postoperative complications were managed appropriately. Surgical Technique
Experienced vitreoretinal surgeons performed all surgeries. Three-port PPV was completed with meticulous
peripheral vitreous dissection, especially in the horizontal meridians where the SSFIOL (PMMA posterior chamber IOL with 2 eyelets, Hanita lenses) was to be anchored. Fixation of SSFIOL was done using 10-0 prolene suture (Ethicon STC6, PR, USA) and a 2-knot 4-point ab externo fixation technique, as described by Rao et al.,9 in all eyes (Fig. 1). A corneal marker was used to ensure accurate placement of the scleral flaps. The rail road technique was used for passing the sutures, and the direction of sutures though the eyelets was changed to neutralize the torque exerted. The knots were buried by rotating them into the eyeball. Scleral flaps and corneoscleral section were secured with 10-0 ethilon suture (Ethicon, PR, USA). Outcome Measures
Preoperative and postoperative visual acuity, refractive outcome, and intraoperative and postoperative complications were the principal outcome measures studied. Statistical Analysis
SPSS 14.0 software (IBM SPSS Statistics, IBM Corporation, Chicago, IL, USA) was used for statistical analysis. Fisher’s exact test with 2-tailed p-values was used for categorical data, and paired and unpaired t tests were used for continuous data. A p-value of 0.05 or less was considered to be statistically significant.
RESULTS Our study included 279 eyes of 230 patients who underwent SSFIOL implantation at age ≤18 years. Of the patients, 74.3% (n ¼ 171) were male and 25.7% (n ¼ 59) were female. The mean age at which SSFIOL was
Fig. 1 — Illustration of the standardized sutured scleral fixated intraocular lenses (SSFIOL) implantation technique.
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Outcomes and complications of SSFIOL in pediatric eyes—Sen et al. implanted was 10.8 ± 4.22 years (range 3.5–18 years). Unilateral SSFIOL implantation was done in 78.7% (n ¼ 181) of patients, and 21.3% (n ¼ 49) had bilateral SSFIOL implantation. The most common indication for SSFIOL implantation in our study was traumatic subluxation of lens in 47.63% (n ¼ 133) of eyes, followed by congenital subluxation in 38.71% (n ¼ 108) of eyes, dislocated IOL in 5.8% (n ¼ 16) of eyes, aphakia after cataract surgery with no capsular support in 3.9% (n ¼ 11) of eyes, and aphakia secondary to previous vitreoretinal surgery in 3.9% (n ¼ 11) of eyes. Primary SSFIOL implantation was done in 71.3% (n ¼ 199), and 28.7% (n ¼ 80) of eyes had aphakia/pseudophakia with previous lens extraction. The mean follow-up after SSFIOL was 39.68 months; 141 eyes (50.5%) had more than 12 months of follow-up, with a mean of 75.48 ± 43.44 months; 84 eyes (30.1%) had more than 60 months of follow-up, with a mean of 104.03 ± 31.86 months; and 26 eyes (9.3%) had more than 120 months of follow-up, with a mean of 143.92 ± 13.56 months. Visual Outcome
Mean BCVA values for preoperative and all postoperative visits are given in Table 1. BCVA in 93.19% eyes was maintained or improved from preoperative visual acuity. Figure 2 shows the comparison between preoperative visual acuity and 6-week postoperative visual acuity. A decrease in visual acuity at the last follow-up visit was seen in 19 eyes (6.8%). The causes for the decrease in vision in these eyes were RD and its sequelae in 7 of 19 eyes, raised IOP in 4 of 19 eyes, amblyopia in 7 of 19 eyes, and atypical retinitis pigmentosa in 1 eye. Spherical error, cylindrical error, and spherical equivalent values for each visit are given in Table 1. There was a significant myopic shift in refraction when refraction at 1 year and last followup visit were compared with refraction 6 weeks postoperatively (Fig. 3). Postoperative Complications and Interventions
Complications included serous choroidal detachment in 2.86% (n ¼ 8), dispersed vitreous hemorrhage in 2.86% (n ¼ 8), endophthalmitis in 0.72% (n ¼ 2), diplopia in 0.72% (n ¼ 2), RD in 5.73% (n ¼ 16), and dislocation of the SSFIOL in 4.7% (n ¼ 13). Raised IOP requiring antiglaucoma medication was seen in 35 (12.54%)
patients in the postoperative period. Diode cyclophotocoagulation was required in 7 (2.5%) cases. Early complications noted in the immediate postoperative period include dispersed vitreous hemorrhage and serous choroidal detachment, which resolved spontaneously. Raised IOP requiring antiglaucoma medication was seen in 35 (12.54%) eyes. Whereas 20 of 279 (7.2%) eyes had pre-existing raised IOP, 15 of 279 (5.4%) eyes developed raised IOP within 4–6 weeks after surgery. In 13 of 15 (86.7%) eyes, the increase in IOP was well controlled with topical antiglaucoma medication. Only 2 (13.3%) eyes required diode or endo cyclophotocoagulation to control IOP. Endophthalmitis was seen in 2 patients. One patient underwent SSFIOL with trabeculectomy. He presented 4 months after surgery with blebitis as well as hypopyon and vitreous exudates. He responded well to topical and intravitreal antibiotics. The second patient had a traumatic subluxation of the lens, for which he underwent primary SSFIOL implantation. The patient developed anterior chamber reaction by the 11th postoperative day. The endophthalmitis was controlled with intravitreal antibiotics. None of the cases developed endophthalmitis related to SSFIOL suture exposure. Long-term complications included RD and IOL dislocation. The incidence of RD in our study was 5.73%. The interval between SSFIOL surgery and occurrence of RD varied from as early as postoperative day 6 to a maximum of 7 years. About one third of the patients (6 of 16 eyes) had RD within 6 weeks after SSFIOL surgery. PVR changes were found in 50% of eyes (8 of 16 eyes). The retina remained attached until the final follow-up after single RD surgery in 11 of 16 eyes (68.75%), and anatomical success was achieved in 3 of 16 eyes (18.75%) after a second surgery. Overall, the retina was successfully reattached in 87.5% of eyes (14 of 16). Two patients had recurrent RD and severe PVR changes with optic atrophy despite multiple surgeries. Visual acuity was maintained or showed improvement in 7 of 16 (43.75%) eyes at the final visit. Eight of 16 eyes had a history of penetrating or blunt trauma, and 2 of these patients had Marfan’s syndrome. IOL dislocation was seen in 13 eyes after a mean duration of 110.3 (range 68–159) months after surgery. A history of minor trauma before dislocation could be elicited in 2 cases. All other children had a sudden spontaneous dislocation. The mean age of patients with
Table 1—BCVA values, spherical error, cylindrical error, and spherical equivalent for all eyes
BCVA p-Value (paired t test) Sphere Cylinder Spherical equivalent p-Value (paired t test)
Preoperative
6 Weeks Postoperative
1 Year Postoperative
Last Follow-Up Visit
1.29 ± 0.80
0.66 ± 0.59 o0.0001 −0.50 ± 2.27 −1.78 ± 1.67 −1.40 ± 2.10
0.55 ± 0.53 o0.0001 −0.92 ± 2.09 −1.85 ± 1.26 −1.80 ± 2.09 0.0205
0.54 ± 0.63 o0.0001 −1.97 ± 3.64 −1.86 ± 1.39 −2.90 ± 3.68 ≤0.001
þ4.15 ± 11.01 −1.31 ± 1.90 þ3.50 ± 11.36
For p-value, postoperative best-corrected visual acuities (BCVAs) were compared with preoperative BCVA, and first year and last follow-up spherical equivalents were compared with sixth week spherical equivalent.
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Outcomes and complications of SSFIOL in pediatric eyes—Sen et al.
Fig. 2 — Scattergram of BCVA in 279 eyes that underwent implantation of SSFIOL. The correlation between pre- and postoperative visual acuity at the sixth week of follow-up is illustrated. Visual acuity is represented in logMAR values. BCVA, best-corrected visual acuity; SSFIOL, sutured scleral fixated intraocular lens.
dislocation at SSFIOL implantation was 10.66 ± 4.67 years, and the mean age of patients without dislocation was 10.8 ± 4.21 years (p ¼ 0.528). The average follow-up was 133.67 ± 30.87 months in patients with dislocation and 35.09 ± 43.39 months in those without dislocation was (p ¼ 0.001). The dislocated IOL was successfully refixated surgically in all these cases. Table 2 illustrates the complications observed in this case series.
DISCUSSION In children, SSFIOL not only serves the purpose of visual rehabilitation but also protects against amblyopia. The current study is one of the largest series of pediatric sutured scleral fixated IOLs, with 279 eyes and an average follow-up of 39.68 months. The youngest child in our study was 3.5 years old, though this procedure has been described for children aged o3 years as well.10
Improvement or stabilization in BCVA was seen in 93.19% of eyes, with maximal improvement seen within the first 6 weeks of surgery. In contrast to a contact lens, which can be used for a maximum of 12 waking hours and must be placed and removed every day, an SSFIOL is continuously present in visual axis, at a position very close to the anatomical location of the natural crystalline lens, resulting in a focused image all the time. This, we believe, is the major advantage of an SSFIOL. A trend toward myopic refraction was seen, as demonstrated by Table 1 and Figure 3. This could be attributed to the increase in axial length of the eyes with increasing age of the children. Other authors have described this as well.11 Vitreous hemorrhage is a common complication12 because the needle for SSFIOL passes through extremely vascular uveal tissue. In our study, less than 3% had dispersed vitreous hemorrhage, which cleared spontaneously in all cases. We believe that having an infusion
Fig. 3 — Vertical bar diagram depicting the distribution of SE after surgery at 6 weeks, 1 year, and at final visit. SSFIOL, sutured scleral fixated intraocular lens; SE, spherical equivalent.
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Outcomes and complications of SSFIOL in pediatric eyes—Sen et al. Table 2—Table showing the postoperative complications, rate and timing of development, and management Complication IOL dislocation Retinal detachment Raised IOP Choroidal detachment Dispersed VH Endophthalmitis Diplopia
Rate, % (n) 4.65 5.73 12.54 2.86 2.86 0.72 0.72
(13) (16) (35) (8) (8) (2) (2)
Mean Duration from Surgery
Range
Management
110.38 ± 25.9 months (9.1 years) 23.54 months 3.09 ± 2.38 weeks 2.62 ± 1.76 days POD 1 4 months, 11th POD 6 weeks
68–159 months POD 6–7 years 1–6 weeks 1–6 days POD 1 11 days–4 months 6 weeks
Refixation of IOL Surgical Medical management in 28, diode CPC in 7 Topical steroids in 7, systemic steroids in 1 patient Conservative Topical þ intravitreal antibiotics Prisms
IOL, intraocular lens; IOP, intraocular pressure; diode CPC, diode cyclophotocoagulation; POD, postoperative day.
cannula in situ throughout the surgical procedure helps to maintain a pressurized globe, thus avoiding this problem. This has also been suggested by Por and Lavin.13 Choroidal detachment seen in our cases was secondary to transient hypotony and resolved with steroids. Vitrectomy, done through the pars plana route in this series of cases, allows the surgeon to meticulously remove peripheral vitreous as well as any capsular remnants before passing the sutures. This reduces the incidence of suture/ haptic entanglement intraoperatively. This also reduces the metabolic activity around the suture. It has been well documented that suture disintegration is maximal at the point where it crosses through highly vascular tissue. Complete PPV before SSFIOL also reduces the long-term risk of RD.14 However, these techniques require the surgery to be performed by experienced vitreoretinal surgeons. We saw RD in 16 out of 279 eyes (5.73%). Of the eyes that developed RD after surgery for SSFIOL, congenital subluxation was seen in 8 eyes (50%) and history of trauma was present in 8 eyes (20%). In as much as trauma and Marfan’s syndrome by themselves are independent risk factors for RD, the percentage of risk that can be attributed to SSFIOL implantation in this subgroup needs to be determined.15 A successful anatomical outcome was
achieved in 87.5% of eyes with an average of 1.43 surgeries (range 1–3) per eye. In a series of 122 eyes in adult cases, Lee et al.16 found RD in 4.9% with a followup of up to 42 months. Asadi and Kheirkhah12 reported a 4% prevalence of RD in patients undergoing SSFIOL with an average follow-up of 3 years. The retinal detachment rate of 5.73% in this case series is comparable. Late endophthalmitis after scleral fixation of IOL has been reported in the literature.17,18 The ab externo technique of scleral fixation was used in all our patients. The knots were not only rotated within the globe but also covered by a partial-thickness scleral flap that was sutured, thereby reducing chances of suture tract–related endophthalmitis.19,20 Whenever it was not possible to rotate the knot inside, longer suture ends were taken and care was taken to cover them by the scleral flaps, which were sutured. None of the cases in our series had late endophthalmitis secondary to knot exposure. Trabeculectomy bleb and infection at the site of wound repair were the source of infection in the 2 eyes that did develop endophthalmitis in this case series. There was no suture erosion or suture-related endophthalmitis in either of these cases. Degradation of polypropylene sutures with time has been well documented in the literature. Jongebloed and
Fig. 4 — Graph showing rate and temporal distribution of complications. 1, endophthalmitis; 2, choroidal detachment; 3, vitreous hemorrhage; 4, raised intraocular pressure; 5, retinal detachment; 6, intraocular lens dislocation. CAN J OPHTHALMOL — VOL. ], NO. ], ] 2017
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Outcomes and complications of SSFIOL in pediatric eyes—Sen et al. Table 3—Comparison of SSFIOL characteristics and complications of this study with previous published literature
Author
Year
Eyes, n
Mean f/u (months)
Kumar et al.22 Zetterström et al.23 Ozmen et al.24 Buckley11 Sewelam25 Bardorf et al.26 Asadi and Kheirkhah12 Burcu et al.27 Current study
1999 1999 2002 2007 2003 2004 2008 2014 2015
11 21 21 33 20 43 25 24 279
10.9 20 22.5 61 19.35 37 81 6 40
Mean Age at SSFIOL,years
Gain/Stable in BCVA, % (n)
6.4 5.8
81.7 (8) 100 (21)
9.7 7.7 10 6.6 11.5 10.8
Complications
81 40 100 48 100 93.19
(27) (8) (43) (12) (24) (260)
1, % (n)
2, % (n)
3, % (n)
4,% (n)
5,% (n)
6,% (n)
7, % (n)
0 0 0 9 (3) 0 0 24 (6) 0 4.65 (13)
0 0 4.7 (1) 0 0 0 4 (1) 0 5.73 (16)
9.09 (1) 0 0 6 (2) 0 5 (2) 0 12.5 (3) 12.54 (35)
0 0 0 3 (1) 0 5 (2) 52 (13) 0 2.86 (8)
0 0 0 0 0 2 (1) 8 (2) 0 2.86 (8)
0 0 4.7 (1) 0 0 0 4 (1) 4.2 (1) 0.72 (2)
18.18 (2) 0 0 0 0 0 0 0
n, number of eyes; f/u, follow-up; SSFIOL, sutured scleral fixated intraocular lens; BCVA, best-corrected visual acuity; 1, intraocular lens dislocation; 2, retinal detachment; 3, raised intraocular pressure; 4, vitreous hemorrhage; 5, choroidal detachment; 6, endophthalmitis; 7, suture exposure.
Worst21 studied a 10-0 polypropylene suture that they had used as a fixation suture for an IOL for a period of 6.5 years. They observed that the suture showed cracks perpendicular to the longitudinal axis of the suture; part of the surface layer was nearly detached or completely missing, and the diameter of the suture was decreased by over 50% in comparison with the original diameter.20 This degradation is considered to be caused by the enzymatic action of ocular fluids. The mean time to dislocation of IOL in our series of cases was 9.2 years. A similar study by Vote et al.6 had a mean time to dislocation of 4 years and that by Buckley11 was 102 months. Vote et al.6 reported dislocations of IOL in 27.9% of cases. Asadi and Kheirkhah12 had a dislocation rate of 24% 7–10 years after surgery. The fixation technique used by Asadi and Kheirkhah12 was 2-point ab externo fixation, whereas we used the 4-point fixation in all cases. Furthermore, in the technique we used to fixate the SSFIOL, there are no intraocular knots. Compared with a conventional 4-knot technique, 2 knots near the 2 haptics of the IOL and 2 knots to fix over the sclera, the technique we used requires only 2 scleral fixating knots as the suture goes through the eyelets of the IOL without any cut ends intraocularly. Because enzymatic activity of tissue fluids causes suture degradation, a meticulous vitrectomy from the area of IOL fixation might have improved the stability of the IOL and reduced the chance of suture breakage, resulting in a dislocation rate of 4.65% in our study. These rates may increase with long-term follow-up in these eyes. Prolene suture degradation is an expected natural event, and fibrosis has not been demonstrated to occur around the haptics. Thus, the SSFIOL is anchored only by means of a degradable suture material. The life span of the 10-0 Prolene remains to be determined, and the risk factors that cause early dissolution in some patients while keeping the suture intact in the rest remain unknown. It is also imperative to identify other suture materials with a longer life span. In addition to suture degradation, risk factors for suture breakage in children could include increase in the size of the eyeball and an increased risk of trauma to the eyeball. Despite the
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dislocation, in all cases of dislocated IOLs, there was neither damage to the retina nor any associated complication, and refixation of the IOL resulted in good visual acuity in all cases. Also, for the time that the IOL was in place it was an effective means of refractive correction, which is particularly important in the pediatric age group. Figure 4 demonstrates the distribution of complications over the follow-up period. Table 3 compares our results with previous published reports on pediatric SSFIOLs. Limitations of the Study
Although our study gives the outcome of PPV with SSFIOL in a large series of pediatric eyes, it is limited by its retrospective nature as well as the absence of randomized comparative data. In addition, for complications like IOL dislocation, longer follow-up may be necessary.
CONCLUSIONS We believe that the continuous presence of IOL in the visual axis in a child’s visual formative years may well play an important role in preventing amblyopia, a very important cause of loss of vision in childhood aphakia. A decrease in visual acuity was observed in 6.81% of eyes in the postoperative period. Retinal detachment can pose a serious threat to vision in these eyes. Furthermore, the complications of RD and IOL dislocations can occur months after the initial surgery. Hence, need for long-term follow-up and education of parents regarding these possible complications cannot be overemphasized. REFERENCES 1. Girard L. Pars plana phaco prosthesis (aphakic intraocular implant): a preliminary report. Ophthalmic Surg. 1981;12:19-22. 2. Malbran ES, Malbran E Jr, Negri I. Lens guide suture for transport and fixation in secondary IOL implantation after intracapsular extraction. Int Ophthalmol. 1986;9:151-60. 3. Stamler JF. The complications of contact lens wear. Curr Opin Ophthalmol. 1998;9:66-71. 4. Kwong YY, Yuen HK, Lam RF, et al. Comparison of outcomes of primary scleral-fixated versus primary anterior chamber intraocular lens implantation in complicated cataract surgeries. Ophthalmology. 2007;114:80-5.
Outcomes and complications of SSFIOL in pediatric eyes—Sen et al. 5. Yen KG, Reddy AK, Weikert MP, et al. Iris fixated posterior chamber intraocular lenses in children. Am J Ophthalmol. 2009;147: 121-6. 6. Vote BJ, Tranos P, Bunce C, et al. Long-term outcome of combined pars plana vitrectomy and scleral fixated sutured posterior chamber intraocular lens implantation. Am J Ophthalmol. 2006;141:308-12. 7. McAllister AS, Hirst LW. Visual outcomes and complications of scleral-fixated posterior chamber intraocular lenses. J Cataract Refract Surg. 2011;37:1263-9. 8. Kjeka O, Bohnstedt J, Meberg K, Seland JH. Implantation of scleral-fixated posterior chamber intraocular lenses in adults. Acta Ophthalmol. 2008;86:537-42. 9. Rao SK, Gopal L, Fogla R, et al. Ab externo 4-point scleral fixation. J Cataract Refract Surg. 2000;26:9-10. 10. Mittelviefhaus H, Mittelviefhaus K, Gerling J. Transscleral suture fixation of posterior chamber intraocular lenses in children under 3 years. Graefes Arch Clin Exp Ophthalmol. 2000;238:143-8. 11. Buckley EG. Hanging by a thread: the long-term efficacy and safety of transscleral sutured intraocular lenses in children (an American Ophthalmological Society thesis). Trans Am Ophthalmol Soc. 2007;105:294-311. 12. Asadi R, Kheirkhah A. Long-term results of scleral fixation of posterior chamber intraocular lenses in children. Ophthalmology. 2008;115:67-72. 13. Por YM, Lavin MJ. Techniques of intraocular lens suspension in the absence of capsular/zonular support. Surv Ophthalmol. 2005;50: 429-62. 14. Johnston RL, Charteris DG, Horgan SE, Cooling RJ. Combined pars plana vitrectomy and sutured posterior chamber implant. Arch Ophthalmol. 2000;118:905-10. 15. Sharma T, Gopal L, Shanmugam MP, et al. Retinal detachment in Marfan syndrome: clinical characteristics and surgical outcome. Retina. 2002;22:423-8. 16. Lee VY, Yuen HK, Kwok AK. Comparison of outcomes of primary and secondary implantation of scleral fixated posterior chamber intraocular lens. Br J Ophthalmol. 2003;87:1459-62. 17. Heilskov T, Joondeph BC, Olsen KR, et al. Late endophthalmitis after transscleral fixation of a posterior chamber intraocular lens. Arch Ophthalmol. 1989;107:1427. 18. Kang HM, Chung EJ. Late-onset Citrobacter koseri endophthalmitis with suture exposure after secondary intraocular lens implantation. Korean J Ophthalmol. 2011;25:285-8. 19. Baykara M, Avci R. Prevention of suture knot exposure in posterior chamber intraocular lens implantation by 4-point scleral
20. 21. 22. 23. 24. 25. 26. 27.
fixation technique. Ophthalmic Surg Lasers Imaging. 2004;35: 379-82. Van Meter WS. Long-term safety of polypropylene knots under scleral flaps for transsclerally sutured posterior chamber lenses. Trans Am Ophthalmol Soc. 1997;95:307-21. discussion 321–7. Jongebloed WL, Worst JF. Degradation of polypropylene in the human eye: a SEM-study. Doc Ophthalmol. 1986;64:143-52. Kumar M, Arora R, Sanga L, Sota LD. Scleral-fixated intraocular lens implantation in unilateral aphakic children. Ophthalmology. 1999;106:2184-9. Zetterström C, Lundvall A, Weeber H Jr, Jeeves M. Sulcus fixation without capsular support in children. J Cataract Refract Surg. 1999;25:776-81. Ozmen AT, Dogru M, Erturk H, Ozcetin H. Transsclerally fixated intraocular lenses in children. Ophthalmic Surg Lasers. 2002;33:394-9. Sewelam A. Four-point fixation of posterior chamber intraocular lenses in children with unilateral aphakia. J Cataract Refract Surg. 2003;29:294-300. Bardorf CM, Epley KD, Lueder GT, Tychsen L. Pediatric transscleral sutured intraocular lenses: efficacy and safety in 43 eyes followed an average of 3 years. J AAPOS. 2004;8:318-24. Burcu A, Yalniz-Akkaya Z, Abay I, Acar MA, Ornek F. Scleralfixated posterior chamber intraocular lens implantation in pediatric and adult patients. Semin Ophthalmol. 2014;29:39-44.
Footnotes and Disclosure: The authors have no proprietary or commercial interest in any material discussed in this article. The authors thank Mr. Vishwanathan for statistical analysis of data. From the Shri Bhagwan Mahavir Vitreoretinal Services, Sankara Nethralaya, Chennai, India. Originally received Apr. 11, 2017. Final revision Jul. 8, 2017. Accepted Jul. 19, 2017. Correspondence to Parveen Sen, MS, Sankara Nethralaya, 18 College Road, Nungambakkam, Chennai 600006, Tamil Nadu, India; [email protected]
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