- Email: [email protected]
Refractive Outcomes after Pars Plana Vitrectomy and Scleral Fixated Intraocular Lens with Gore-Tex Suture
Refractive Outcomes after Pars Plana Vitrectomy and Scleral Fixated Intraocular Lens with Gore-Tex Suture Daniel Su, MD,1 John D. Stephens, MD,1 Anthony Obeid, MD, MPH,1 Durga Borkar, MD,1 Philip P. Storey, MD,1 M. Ali Khan, MD,1,2 Jason Hsu, MD,1 Sunir J. Garg, MD,1 Omesh Gupta, MD1 Purpose: To evaluate refractive outcomes after combined pars plana vitrectomy (PPV) and scleral fixation of an intraocular lens (IOL) using Gore-Tex suture. Design: Retrospective cohort study. Participants: Fifty-five eyes from 53 patients who underwent PPV with a Gore-Tex sutured IOL from June 2013 through December 2017. Methods: Patients who underwent combined PPV and scleral fixation of an IOL with Gore-Tex suture were identified. All eyes underwent scleral fixation of either an Akreos A060 or enVista MX60 IOL and were fixated either 2 mm or 3 mm posterior to the limbus. Postoperative manifest refractions were performed at least 3 months after surgery and were compared with preoperative predicted target refraction based on in-the-bag IOL calculations. Subgroup analyses based on sclerotomy placement and IOL models were performed. Main Outcome Measures: Postoperative manifest refraction and difference with sclerotomy placement and IOL model. Results: The mean postoperative spherical equivalent (SEQ) was e0.991.00 diopters (D). The mean difference in SEQ (DSEQ) from preoperative predicted target was e0.641.00 D. The IOL was fixated 2 mm posterior to the limbus in 14 eyes and 3 mm in 41 eyes. Within these 2 subgroups, the mean postoperative SEQ was e1.531.35 D for fixation 2 mm posterior to the limbus and e0.820.83 D for fixation 3 mm posterior to the limbus (P ¼ 0.09). The mean DSEQ was e0.430.71 D for fixation 3 mm posterior to the limbus and e1.351.32 D for fixation 2 mm posterior to the limbus (P ¼ 0.03). The mean amount of surgically induced astigmatism in the overall cohort was 0.770.65 D. The mean DSEQ and induced astigmatism were similar between IOL models. Conclusions: After combined PPV and Gore-Texesutured IOL implantation, mean postoperative refractive outcomes were more myopic when the IOL was fixated 2 mm from the limbus compared with 3 mm from the limbus. No significant difference was found between IOL models. Based on these results, future implant power calculations may be adjusted to approximate preoperative target refraction more accurately. Ophthalmology Retina 2019;3:548-552 ª 2019 by the American Academy of Ophthalmology
In the management of aphakia without adequate capsular support, multiple innovative surgical techniques have been developed.1e8 Recently, Khan et al9 described favorable 1-year outcomes with combined pars plana vitrectomy (PPV) and scleral fixation of a posterior chamber intraocular lens (IOL) using Gore-Tex suture. A subsequent investigation comparing outcomes of this technique with combined PPV and anterior chamber IOL placement revealed similar visual outcomes with reduced rates of postoperative complications, including early corneal edema.10 These studies validated this relatively new technique in routine clinical practice. The most common surgical indications for secondary IOL are dislocated IOL, malpositioned anterior chamber IOL, retained lens material, aphakia, and subluxed crystalline lens.9,10 In the absence of concurrent retinal disease, this cohort of patients generally has excellent visual potential. As a result, achieving the targeted refraction is an
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2019 by the American Academy of Ophthalmology Published by Elsevier Inc.
important outcome measure, just as it is in routine cataract surgery.11 Despite this, refractive outcomes after scleral fixation with Gore-Tex suture have not been described over a large cohort. The purpose of this study was to evaluate refractive outcomes after PPV and scleral-fixated IOLs using Gore-Tex suture.
Methods This retrospective, interventional case series adhered to the tenets of the Declaration of Helsinki and was approved by the institutional review board for Wills Eye Hospital. Informed consent was waived by the IRB due to the retrospective nature of the study. The research was conducted in accordance with regulations set forth by the Health Insurance Portability and Accountability Act. Patients who underwent combined PPV and scleral fixation of an Akreos A060 or enVista MX60 IOL (Bausch and Lomb, Bridgewater, NJ) https://doi.org/10.1016/j.oret.2019.02.012 ISSN 2468-6530/19
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Refractive Outcomes with Scleral Sutured IOL
using Gore-Tex suture (W.L. Gore & Associates, Elkton, MD) between June 2013 and December 2017 were eligible for inclusion in the study. Patient records were reviewed and the following data were collected: age, gender, preoperative and postoperative best available Snellen visual acuity with pinhole, and surgical indications. All patients were identified from surgical operative reports for current procedural terminology codes 66985 (insertion of IOL prosthesis, not associated with concurrent cataract removal), 66986 (exchange of IOL), and 66825 (repositioning of an IOL prosthesis). Surgical indications included IOL dislocation, retained lens material without IOL implantation at time of cataract surgery, subluxed crystalline lens, and aphakia. Patients with severe glaucoma or retinal pathologic features resulting in an inability to be refracted were excluded from the study. The surgical technique has been described previously.6 In brief, a toric lens marker was used to mark the corneal limbus at 2 points 180 apart. Limited nasal and temporal conjunctival peritomies were fashioned, and 4 separate sclerotomy sites (2 nasal and 2 temporal) then were marked with calipers. Each pair of sclerotomies was made either 2 mm or 3 mm posterior to the limbus and 3 to 5 mm apart. After 2015, sclerotomy sites were made exclusively 3 mm posterior to the limbus to minimize iris chafing and vitreous hemorrhage resulting from trauma to the pars plicata. Self-retaining valved cannulas were placed in the superonasal and superotemporal sclerotomy sites and a standard 3-port PPV was performed. A clear corneal incision was then made using a 2.75-mm keratome and enlarged to 3.5 to 4 mm. The CV-8 Gore-Tex suture was cut into equal halves and laced through each pair of adjacent eyelets of the Akreos A060, or through each eyelet of a MX60 IOL with both ends of the suture going over the haptic. In a hand-to-hand technique, each end of the Gore-Tex suture was passed into the anterior chamber and externalized from each corresponding sclerotomy using intraocular forceps. The IOL then was folded in half and introduced into the anterior chamber. The sutures were tied using a 3-1-1 or slip-knot technique to center the IOL. The suture knots were trimmed and rotated into a sclerotomy. The corneal incision and conjunctival peritomies then were sutured. Before 2017, an Akreos A060 lens was used exclusively with this surgical technique. However, after reports of lens opacification with gas or air tamponade in 2017,12 the MX60 lens became the implant used predominantly with this surgical technique. Preoperative lens calculations were performed using either optical biometry (IOLMaster; Carl Zeiss Meditec, Dublin, CA) or immersion ultrasonography (Eye Cubed; Ellex, Inc, Minneapolis, MN). In cases of retained lens fragment without IOL implantation, the referring provider performed the preoperative biometry before cataract surgery. When placing sclerotomies 2 mm posterior to the limbus, a sulcus-based calculation is performed. This typically involves reducing the IOL power by 0.5 to 1.0 diopter (D). For sclerotomies 3 mm posterior to the limbus, a routine in-the-bag calculation was performed. The preoperative biometry calculations were reviewed and the axial length, keratometry, and corneal astigmatism were recorded. Operative reports were reviewed for the model and power of the implanted IOL. Based on the IOL implanted, the targeted preoperative refraction in spherical equivalent (SEQ) using in-the-bag calculations was recorded. The formula used in each IOL calculation was based on axial length. For axial lengths of less than 22 mm, the HofferQ formula was used. The Holladay formula was used for axial lengths between 22 and 26 mm, and the SandersRetzlaff-Kraff trial formula was used for axial lengths of more than 26 mm.13
Table 1. Baseline Characteristics of Patients and Eyes Undergoing Pars Plana Vitrectomy and Scleral Fixation of an Intraocular Lens Using Gore-Tex Suture Characteristic
Data
Age (yrs), mean SD Gender, no. (%) Male Female Surgical indication, no. of eyes (%) Dislocated IOL Retained lens material Subluxation of crystalline lens Aphakia Visual acuity (logMAR), mean SD Preoperative Postoperative
70.016.5 31 (58.5) 22 (41.5) 34 9 7 5
(61.8) (16.4) (12.7) (9.1)
1.450.86 0.490.52
IOL ¼ intraocular lens; logMAR ¼ logarithm of the minimum angle of resolution; SD ¼ standard deviation.
Postoperative manifest refractions performed at least 3 months after surgery were obtained from the referring eye provider. The postoperative SEQ then was calculated and compared with the preoperative target to yield the difference in SEQ (DSEQ). The DSEQ was correlated with the axial length, corneal power, and IOL power. Subgroup analyses for IOL model and sclerotomy placements also were performed. The amount of surgically induced astigmatism (SIA) was calculated and compared between IOL models.
Statistical Analysis All statistical tests were performed using SPSS software version 24 (SPSS, Inc, Armonk, NY). Snellen visual acuity measurements were converted into the logarithm of the minimum angle of resolution for analysis. Univariate linear regression was used to determine the correlation between continuous data, and differences between independent groups was evaluated using the independent t test. Statistical significance was considered as a P value of less than 0.05.
Results Fifty-five eyes of 53 patients were included in the study. Patient characteristics are summarized in Table 1. Indications for surgery included dislocated IOL (34 eyes), retained lens material without IOL implantation (9 eyes), subluxed crystalline lens (7 eyes), and aphakia (5 eyes). A Bausch and Lomb Akreos A060 IOL was implanted in 47 eyes and a Bausch and Lomb enVista MX60 IOL was implanted in 8 eyes. There was a significant improvement in meanstandard deviation VA at the 3-month follow-up visit (0.490.52 logarithm of the minimum angle of resolution; Snellen equivalent, 20/62) compared with the baseline visit (1.450.86 logarithm of the minimum angle of resolution; Snellen equivalent, 20/564; P < 0.001). The mean follow-up period was 9.7 months. The mean postoperative SEQ was e0.991.00 D. The mean DSEQ from preoperative predicted SEQ was e0.641.00 D. There was no correlation between DSEQ and axial length (r ¼ 0.05; P ¼ 0.73), corneal power (r ¼ 0.16; P ¼ 0.25), or IOL power (r ¼ e0.07; P ¼ 0.61).
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Figure 1. Box-and-whisker plot showing the mean postoperative spherical equivalent (SEQ) refraction was e0.991.00 diopter (D) for all eyes. For subgroup analysis based on sclerotomy placement, the mean postoperative SEQ refraction was e1.531.35 D for fixation 2 mm posterior to the limbus and e0.820.83 D for fixation 3 mm posterior to the limbus (P ¼ 0.09). Refractive outcomes were more myopic when the intraocular lens was placed 2 mm from the limbus compared with 3 mm from the limbus with a trend toward significance.
The IOL was fixated 2 mm posterior to the limbus in 13 eyes and 3 mm from the limbus in 42 eyes. Within these 2 subgroups, the mean preoperative predicted SEQ was e0.180.40 D for fixation 2 mm posterior to the limbus and e0.410.38 D for fixation 3 mm posterior to the limbus (P ¼ 0.03). The mean postoperative SEQ was e1.531.35 D for fixation 2 mm posterior to the limbus and e0.820.83 D for fixation 3 mm posterior to the limbus (P ¼ 0.09; Fig 1). The mean DSEQ was e1.351.32 D and e0.430.71 D for fixation 2 mm and 3 mm posterior to the limbus, respectively (P ¼ 0.03). All 13 eyes in the 2-mm group received an Akreos A060 IOL. Of the 42 eyes in the 3-mm group, 34 (81%) received an Akreos A060 IOL and 8 (19%) received an enVista MX60 IOL. Among the 42 eyes that underwent fixation 3 mm posterior to the limbus, the mean DSEQ was not significantly different between the Akreos A060 and the enVista MX60 (e0.430.71 D and e0.361.02 D, respectively; P ¼ 0.82; Fig 2). The mean amount of SIA was 0.770.65 D and was similar between the Akreos A060 and the enVista MX60 IOLs (0.730.59 D and 0.580.71 D, respectively; P ¼ 0.54; Fig 3).
Figure 2. Box-and-whisker plot showing that among eyes that underwent intraocular lens (IOL) fixation 3 mm posterior to the limbus, the mean difference in spherical equivalent (DSEQ) refraction from the preoperative target was similar between the 2 IOL models. The mean DSEQ refraction was e0.430.71 diopter (D) for the Akreos A060 IOL and e0.361.02 D for the enVista MX60 IOL (P ¼ 0.82).
underwent sutureless scleral fixation of an IOL via scleral tunnels created using either trocar cannulas3 or an microvitreoretinal blade.4 In those reports, haptics of a 3piece IOL were fixated either 1.5 or 2 mm posterior to the limbus. The mean overall difference between postoperative SEQ and preoperative target was þ0.41 D. Interestingly, IOL placement 1.5 mm posterior to the limbus resulted in a more hyperopic outcome than IOL placement 2 mm posterior to the limbus. These studies highlight the fact that refractive outcomes after secondary IOL placement are dependent on the surgical technique used and also distance of fixation from the limbus, warranting investigation with each new technique. When our institution first reported this technique in 2014,6 sclerotomies were placed 2 mm posterior to the limbus. However since 2015, sclerotomy sites have been made 3 mm posterior to the limbus to minimize iris chafing and vitreous hemorrhage from the pars plicata. Comparing refractive outcomes between these 2 subgroups, the mean preoperative predicted target was
Discussion Favorable outcomes have been demonstrated using GoreTex suture to fixate an IOL to the sclera in cases of aphakia without adequate capsular support.9,10 To refine this surgical technique further, we report postoperative refractive outcomes in this retrospective analysis. Without other significant ocular pathologic features, patients requiring secondary IOL placement typically have excellent visual potential and good postoperative refraction is expected. Refractive outcomes using different scleral fixation techniques have been reported previously. Hayashi et al14 reported refractive outcomes with scleral-sutured IOL using 10-0 polypropylene sutures with a long curved needle 1 mm posterior to the surgical limbus and found the mean SEQ error to be e0.65 D from the predicted target. Abbey et al15 reported refractive outcomes on a series of 22 eyes that
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Figure 3. Box-and-whisker plot showing that the mean surgically induced astigmatism was 0.770.65 diopter (D) for all eyes and was similar between the 2 different intraocular lens models. The mean surgically induced astigmatism was 0.730.59 D for the Akreos A060 lens and 0.580.71 D for the enVista MX60 lens (P ¼ 0.54).
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Refractive Outcomes with Scleral Sutured IOL
closer to plano for the 2-mm group than the 3-mm group. This is because of sulcus-based calculations when placing sclerotomies 2 mm posterior to the limbus, which typically involves reducing the in-the-bag IOL power by 0.5 to 1.0 D.16 Despite this adjustment, eyes with IOL fixation 2 mm posterior to the limbus ended up more myopic than those with fixation 3 mm posterior to the limbus, with a trend toward significance. This is likely because without data on refractive outcomes, surgeons were not as aggressive in reducing the IOL power for sulcus-based calculations to avoid hyperopic outcomes. Refractive outcomes for eyes with IOL fixation 3 mm posterior to the limbus were less than 0.5 D more myopic than the preoperative target based on in-the-bag calculations. Correlation analysis between the mean change in postoperative refraction compared with the preoperative target (DSEQ) and the axial length, corneal power, and IOL power did not reveal a significant relationship. It is possible that a relationship may be found with a larger sample size. For example, at the extreme ends of the spectrum (very short or very long eyes), fixation of the IOL at 3 mm posterior to the limbus may result in different refractive outcomes. However, this may be compensated for partially by using IOL formulas that more accurately predict the postoperative result. Surgically induced astigmatism at the corneal plane is determined by the size and location of the corneal incision. Clear corneal incisions in cataract surgery with phacoemulsification range from 2.2 to 4 mm.17,18 The amount of SIA may range from 0.24 to 1.65 D, depending on the size and location of the incision.18 In the current study, the mean SIA of 0.77 D was comparable with those found after cataract surgery with incisions of similar sizes.18 In addition to SIA at the corneal plane, scleral-fixated IOL may be more susceptible to lens tilt, which can induce astigmatism and higher-order aberrations.19 The Akreos A060 IOL theoretically decreases the risk of lens tilt and amount of induced astigmatism because of its 4-point fixation; however, the mean SIA was similar between the 2 IOL models in the current study. Further investigation with anterior segment OCT to quantify the amount of lens tilt between IOL models may be warranted. Our institution previously commented on the surgical learning curve encountered with new techniques and offered several suggestions to improve surgical performance.9,10 This article highlights the importance of consistency in sclerotomy site placement. To reduce chances of so-called refractive surprise, each sclerotomy site should be measured and marked to ensure an accurate and uniform distance from the limbus and each other. Small errors in sclerotomy placement can result in large variations in postoperative refractive outcome. Placing the sclerotomies more posterior than intended may result in a hyperopic outcome, whereas anterior placement may result in a myopic outcome and may increase the potential of iris chafing and ciliary body trauma. Appropriate suture tension also is critical. Too much suture laxity may result in lens movement and unpredictable refractive outcomes, whereas overly tight sutures may result in bending of the lens, resulting in irregular astigmatism. Because of these surgeon-dependent
factors, tracking of postoperative refractive outcomes is essential to refine individual surgical technique to produce more accurate results. This study has several limitations. Because of its retrospective nature, there may be a selection bias toward patients with more significant refractive errors because only patients with postoperative refractions were included. In addition, because the primary outcome in this study was refractive outcomes and not best-corrected visual acuity, we did not specifically exclude patients with a history of retinal pathologic features limiting visual acuity. However, patients who were unable to be refracted because of severe glaucomatous or retinal pathologic features were excluded from the study. In addition, the distance between sclerotomies (3e5 mm apart) was not included as a study variable. This is less likely to be a determining factor in postoperative refraction as long as appropriate suture tension is applied, but it is possible that variations in the distance between sclerotomies may affect the refractive outcome. Finally, we had a relatively small sample size of eyes in which MX60 IOLs were placed, which may have limited the power of analysis to detect significant differences in the amount of SIA between IOL models. In summary, we report postoperative refractive outcomes after combined PPV and scleral-fixated IOL with Gore-Tex suture. Mean postoperative SEQ was closer to the desired target when the IOL was placed 3 mm from the limbus compared with 2 mm from the limbus. These data may be useful for other surgeons performing this technique to understand how lens power calculations may be adjusted to refine the refractive outcome. References 1. Wagoner MD, Cox TA, Ariyasu RG, et al. Intraocular lens implantation in the absence of capsular support: a report by the American Academy of Ophthalmology. Ophthalmology. 2003;110:840e859. 2. Maggi R, Maggi C. Sutureless scleral fixation of intraocular lenses. J Cataract Refract Surg. 1997;23:1289e1294. 3. Prasad S. Transconjunctival sutureless haptic fixation of posterior chamber IOL: a minimally traumatic approach for IOL rescue or secondary implantation. Retina. 2013;33:657e660. 4. Prenner JL, Feiner L, Wheatley HM, Connors D. A novel approach for posterior chamber intraocular lens placement or rescue via a sutureless scleral fixation technique. Retina. 2012;32:853e855. 5. Todorich B, Thanos A, Woodward MA, Wolfe JD. Sutureless intrascleral fixation of secondary intraocular lens using 27gauge vitrectomy system. Ophthalmic Surg Lasers Imaging Retina. 2016;47:376e379. 6. Khan MA, Gerstenblith AT, Dollin ML, et al. Scleral fixation of posterior chamber intraocular lenses using Gore-Tex suture with concurrent 23-gauge pars plana vitrectomy. Retina. 2014;34:1477e1480. 7. Yamane S, Inoue M, Arakawa A, Kadonosono K. Sutureless 27-gauge needle-guided intrascleral intraocular lens implantation with lamellar scleral dissection. Ophthalmology. 2014;121:61e66. 8. Jacob S, Agarwal A, Agarwal A, et al. Glued capsular hook: technique for fibrin glue-assisted sutureless transscleral fixation of the capsular bag in subluxated cataracts and intraocular lenses. J Cataract Refract Surg. 2014;40:1958e1965.
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Ophthalmology Retina Volume 3, Number 7, July 2019 9. Khan MA, Samara WA, Gerstenblith AT, et al. Combined pars plana vitrectomy and scleral fixation of an intraocular lens using Gore-Tex suture: one-year outcomes. Retina. 2017;38: 1377e1384. 10. Khan MA, Gupta OP, Pendi K, et al. Pars plana vitrectomy with anterior chamber versus Gore-Tex sutured posterior chamber intraocular lens placement: long-term outcomes. Retina. 2019;39:860e866. 11. Mahmud I, Kelley T, Stowell C, et al. A proposed minimum standard set of outcome measures for cataract surgery. JAMA Ophthalmol. 2015;133:1247e1252. 12. Kalevar A, Dollin M, Gupta RR. Opacification of scleral-sutured Akreos A060 intraocular lens after vitrectomy with gas tamponade: case series. Retin Cases Brief Rep. 2017. In Press. 13. Hoffer KJ. Clinical results using the Holladay 2 intraocular lens power formula. J Cataract Refract Surg. 2000;26: 1233e1237. 14. Hayashi K, Hayashi H, Nakao F, Hayashi F. Intraocular lens tilt and decentration, anterior chamber depth, and refractive
15.
16. 17. 18.
19.
error after trans-scleral suture fixation surgery. Ophthalmology. 1999;106:878e882. Abbey AM, Hussain RM, Shah AR, et al. Sutureless scleral fixation of intraocular lenses: outcomes of two approaches. The 2014 Yasuo Tano Memorial Lecture. Graefes Arch Clin Exp Ophthalmol. 2015;253:1e5. Dubey R, Birchall W, Grigg J. Improved refractive outcome for ciliary sulcus-implanted intraocular lenses. Ophthalmology. 2012;119:261e265. Can I, Takmaz T, Yildiz Y, et al. Coaxial, microcoaxial, and biaxial microincision cataract surgery: prospective comparative study. J Cataract Refract Surg. 2010;36:740e746. Theodoulidou S, Asproudis I, Athanasiadis A, et al. Comparison of surgically induced astigmatism among different surgeons performing the same incision. Int J Ophthalmol. 2017;10:1004e1007. Stem MS, Todorich B, Woodward MA, et al. Scleral-fixated intraocular lenses: past and present. J Vitreoretin Dis. 2017;1: 144e152.
Footnotes and Financial Disclosures Originally received: September 27, 2018. Final revision: February 8, 2019. Accepted: February 19, 2019. Available online: March 2, 2019. Manuscript no. ORET_2018_407. 1
Retina Service, Wills Eye Hospital, Philadelphia, Pennsylvania.
2
Accountability (HIPAA) Act of 1996 and adhered to the tenets of the Declaration of Helsinki. No animal subjects were included in this study. Author Contributions: Conception and design: Su, Obeid, Khan, Hsu, Garg, Gupta.
Retina Division, Doheny and Stein Eye Institutes, David Geffen School of Medicine at UCLA, Los Angeles, California.
Analysis and interpretation: Su, Stephens, Obeid, Hsu, Garg, Gupta.
Presented at: Retina Society Annual Meeting, September 2018, San Francisco, California.
Obtained funding: N/A
Financial Disclosure(s): The author(s) have made the following disclosure(s): M.A.K.: Financial support e Allergan. J.H.: Consultant e UCB (Brussels, Belgium); Financial support e Roche/ Genentech, Santen, Ophthotech. S.J.G.: Consultant e Deciphera, Santen, Bausch and Lomb, Topivert; Financial support e Aerpio, Allergan, Eyegate, Apellis. HUMAN SUBJECTS: Human subjects were included in this study. The institutional review board at Wills Eye Hospital approved the study. Informed consent was waived by the IRB due to the retrospective nature of the study. All research complied with the Health Insurance Portability and
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Data collection: Su, Stephens, Obeid, Borkar, Storey, Khan. Overall responsibility: Su, Stephens, Obeid, Borkar, Storey, Khan, Hsu, Garg, Gupta. Abbreviations and Acronyms: D ¼ diopter; IOL ¼ intraocular lens; PPV ¼ pars plana vitrectomy; SEQ ¼ spherical equivalent; SIA ¼ surgically induced astigmatism; DSEQ ¼ difference in spherical equivalent. Correspondence: Omesh Gupta, MD, Retina Service, Wills Eye Hospital, Mid Atlantic Retina, 840 Walnut Street, Suite 1020, Philadelphia, PA 19107. E-mail: [email protected].
In the management of aphakia without adequate capsular support, multiple innovative surgical techniques have been developed.1e8 Recently, Khan et al9 described favorable 1-year outcomes with combined pars plana vitrectomy (PPV) and scleral fixation of a posterior chamber intraocular lens (IOL) using Gore-Tex suture. A subsequent investigation comparing outcomes of this technique with combined PPV and anterior chamber IOL placement revealed similar visual outcomes with reduced rates of postoperative complications, including early corneal edema.10 These studies validated this relatively new technique in routine clinical practice. The most common surgical indications for secondary IOL are dislocated IOL, malpositioned anterior chamber IOL, retained lens material, aphakia, and subluxed crystalline lens.9,10 In the absence of concurrent retinal disease, this cohort of patients generally has excellent visual potential. As a result, achieving the targeted refraction is an
548
2019 by the American Academy of Ophthalmology Published by Elsevier Inc.
important outcome measure, just as it is in routine cataract surgery.11 Despite this, refractive outcomes after scleral fixation with Gore-Tex suture have not been described over a large cohort. The purpose of this study was to evaluate refractive outcomes after PPV and scleral-fixated IOLs using Gore-Tex suture.
Methods This retrospective, interventional case series adhered to the tenets of the Declaration of Helsinki and was approved by the institutional review board for Wills Eye Hospital. Informed consent was waived by the IRB due to the retrospective nature of the study. The research was conducted in accordance with regulations set forth by the Health Insurance Portability and Accountability Act. Patients who underwent combined PPV and scleral fixation of an Akreos A060 or enVista MX60 IOL (Bausch and Lomb, Bridgewater, NJ) https://doi.org/10.1016/j.oret.2019.02.012 ISSN 2468-6530/19
Su et al
Refractive Outcomes with Scleral Sutured IOL
using Gore-Tex suture (W.L. Gore & Associates, Elkton, MD) between June 2013 and December 2017 were eligible for inclusion in the study. Patient records were reviewed and the following data were collected: age, gender, preoperative and postoperative best available Snellen visual acuity with pinhole, and surgical indications. All patients were identified from surgical operative reports for current procedural terminology codes 66985 (insertion of IOL prosthesis, not associated with concurrent cataract removal), 66986 (exchange of IOL), and 66825 (repositioning of an IOL prosthesis). Surgical indications included IOL dislocation, retained lens material without IOL implantation at time of cataract surgery, subluxed crystalline lens, and aphakia. Patients with severe glaucoma or retinal pathologic features resulting in an inability to be refracted were excluded from the study. The surgical technique has been described previously.6 In brief, a toric lens marker was used to mark the corneal limbus at 2 points 180 apart. Limited nasal and temporal conjunctival peritomies were fashioned, and 4 separate sclerotomy sites (2 nasal and 2 temporal) then were marked with calipers. Each pair of sclerotomies was made either 2 mm or 3 mm posterior to the limbus and 3 to 5 mm apart. After 2015, sclerotomy sites were made exclusively 3 mm posterior to the limbus to minimize iris chafing and vitreous hemorrhage resulting from trauma to the pars plicata. Self-retaining valved cannulas were placed in the superonasal and superotemporal sclerotomy sites and a standard 3-port PPV was performed. A clear corneal incision was then made using a 2.75-mm keratome and enlarged to 3.5 to 4 mm. The CV-8 Gore-Tex suture was cut into equal halves and laced through each pair of adjacent eyelets of the Akreos A060, or through each eyelet of a MX60 IOL with both ends of the suture going over the haptic. In a hand-to-hand technique, each end of the Gore-Tex suture was passed into the anterior chamber and externalized from each corresponding sclerotomy using intraocular forceps. The IOL then was folded in half and introduced into the anterior chamber. The sutures were tied using a 3-1-1 or slip-knot technique to center the IOL. The suture knots were trimmed and rotated into a sclerotomy. The corneal incision and conjunctival peritomies then were sutured. Before 2017, an Akreos A060 lens was used exclusively with this surgical technique. However, after reports of lens opacification with gas or air tamponade in 2017,12 the MX60 lens became the implant used predominantly with this surgical technique. Preoperative lens calculations were performed using either optical biometry (IOLMaster; Carl Zeiss Meditec, Dublin, CA) or immersion ultrasonography (Eye Cubed; Ellex, Inc, Minneapolis, MN). In cases of retained lens fragment without IOL implantation, the referring provider performed the preoperative biometry before cataract surgery. When placing sclerotomies 2 mm posterior to the limbus, a sulcus-based calculation is performed. This typically involves reducing the IOL power by 0.5 to 1.0 diopter (D). For sclerotomies 3 mm posterior to the limbus, a routine in-the-bag calculation was performed. The preoperative biometry calculations were reviewed and the axial length, keratometry, and corneal astigmatism were recorded. Operative reports were reviewed for the model and power of the implanted IOL. Based on the IOL implanted, the targeted preoperative refraction in spherical equivalent (SEQ) using in-the-bag calculations was recorded. The formula used in each IOL calculation was based on axial length. For axial lengths of less than 22 mm, the HofferQ formula was used. The Holladay formula was used for axial lengths between 22 and 26 mm, and the SandersRetzlaff-Kraff trial formula was used for axial lengths of more than 26 mm.13
Table 1. Baseline Characteristics of Patients and Eyes Undergoing Pars Plana Vitrectomy and Scleral Fixation of an Intraocular Lens Using Gore-Tex Suture Characteristic
Data
Age (yrs), mean SD Gender, no. (%) Male Female Surgical indication, no. of eyes (%) Dislocated IOL Retained lens material Subluxation of crystalline lens Aphakia Visual acuity (logMAR), mean SD Preoperative Postoperative
70.016.5 31 (58.5) 22 (41.5) 34 9 7 5
(61.8) (16.4) (12.7) (9.1)
1.450.86 0.490.52
IOL ¼ intraocular lens; logMAR ¼ logarithm of the minimum angle of resolution; SD ¼ standard deviation.
Postoperative manifest refractions performed at least 3 months after surgery were obtained from the referring eye provider. The postoperative SEQ then was calculated and compared with the preoperative target to yield the difference in SEQ (DSEQ). The DSEQ was correlated with the axial length, corneal power, and IOL power. Subgroup analyses for IOL model and sclerotomy placements also were performed. The amount of surgically induced astigmatism (SIA) was calculated and compared between IOL models.
Statistical Analysis All statistical tests were performed using SPSS software version 24 (SPSS, Inc, Armonk, NY). Snellen visual acuity measurements were converted into the logarithm of the minimum angle of resolution for analysis. Univariate linear regression was used to determine the correlation between continuous data, and differences between independent groups was evaluated using the independent t test. Statistical significance was considered as a P value of less than 0.05.
Results Fifty-five eyes of 53 patients were included in the study. Patient characteristics are summarized in Table 1. Indications for surgery included dislocated IOL (34 eyes), retained lens material without IOL implantation (9 eyes), subluxed crystalline lens (7 eyes), and aphakia (5 eyes). A Bausch and Lomb Akreos A060 IOL was implanted in 47 eyes and a Bausch and Lomb enVista MX60 IOL was implanted in 8 eyes. There was a significant improvement in meanstandard deviation VA at the 3-month follow-up visit (0.490.52 logarithm of the minimum angle of resolution; Snellen equivalent, 20/62) compared with the baseline visit (1.450.86 logarithm of the minimum angle of resolution; Snellen equivalent, 20/564; P < 0.001). The mean follow-up period was 9.7 months. The mean postoperative SEQ was e0.991.00 D. The mean DSEQ from preoperative predicted SEQ was e0.641.00 D. There was no correlation between DSEQ and axial length (r ¼ 0.05; P ¼ 0.73), corneal power (r ¼ 0.16; P ¼ 0.25), or IOL power (r ¼ e0.07; P ¼ 0.61).
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Figure 1. Box-and-whisker plot showing the mean postoperative spherical equivalent (SEQ) refraction was e0.991.00 diopter (D) for all eyes. For subgroup analysis based on sclerotomy placement, the mean postoperative SEQ refraction was e1.531.35 D for fixation 2 mm posterior to the limbus and e0.820.83 D for fixation 3 mm posterior to the limbus (P ¼ 0.09). Refractive outcomes were more myopic when the intraocular lens was placed 2 mm from the limbus compared with 3 mm from the limbus with a trend toward significance.
The IOL was fixated 2 mm posterior to the limbus in 13 eyes and 3 mm from the limbus in 42 eyes. Within these 2 subgroups, the mean preoperative predicted SEQ was e0.180.40 D for fixation 2 mm posterior to the limbus and e0.410.38 D for fixation 3 mm posterior to the limbus (P ¼ 0.03). The mean postoperative SEQ was e1.531.35 D for fixation 2 mm posterior to the limbus and e0.820.83 D for fixation 3 mm posterior to the limbus (P ¼ 0.09; Fig 1). The mean DSEQ was e1.351.32 D and e0.430.71 D for fixation 2 mm and 3 mm posterior to the limbus, respectively (P ¼ 0.03). All 13 eyes in the 2-mm group received an Akreos A060 IOL. Of the 42 eyes in the 3-mm group, 34 (81%) received an Akreos A060 IOL and 8 (19%) received an enVista MX60 IOL. Among the 42 eyes that underwent fixation 3 mm posterior to the limbus, the mean DSEQ was not significantly different between the Akreos A060 and the enVista MX60 (e0.430.71 D and e0.361.02 D, respectively; P ¼ 0.82; Fig 2). The mean amount of SIA was 0.770.65 D and was similar between the Akreos A060 and the enVista MX60 IOLs (0.730.59 D and 0.580.71 D, respectively; P ¼ 0.54; Fig 3).
Figure 2. Box-and-whisker plot showing that among eyes that underwent intraocular lens (IOL) fixation 3 mm posterior to the limbus, the mean difference in spherical equivalent (DSEQ) refraction from the preoperative target was similar between the 2 IOL models. The mean DSEQ refraction was e0.430.71 diopter (D) for the Akreos A060 IOL and e0.361.02 D for the enVista MX60 IOL (P ¼ 0.82).
underwent sutureless scleral fixation of an IOL via scleral tunnels created using either trocar cannulas3 or an microvitreoretinal blade.4 In those reports, haptics of a 3piece IOL were fixated either 1.5 or 2 mm posterior to the limbus. The mean overall difference between postoperative SEQ and preoperative target was þ0.41 D. Interestingly, IOL placement 1.5 mm posterior to the limbus resulted in a more hyperopic outcome than IOL placement 2 mm posterior to the limbus. These studies highlight the fact that refractive outcomes after secondary IOL placement are dependent on the surgical technique used and also distance of fixation from the limbus, warranting investigation with each new technique. When our institution first reported this technique in 2014,6 sclerotomies were placed 2 mm posterior to the limbus. However since 2015, sclerotomy sites have been made 3 mm posterior to the limbus to minimize iris chafing and vitreous hemorrhage from the pars plicata. Comparing refractive outcomes between these 2 subgroups, the mean preoperative predicted target was
Discussion Favorable outcomes have been demonstrated using GoreTex suture to fixate an IOL to the sclera in cases of aphakia without adequate capsular support.9,10 To refine this surgical technique further, we report postoperative refractive outcomes in this retrospective analysis. Without other significant ocular pathologic features, patients requiring secondary IOL placement typically have excellent visual potential and good postoperative refraction is expected. Refractive outcomes using different scleral fixation techniques have been reported previously. Hayashi et al14 reported refractive outcomes with scleral-sutured IOL using 10-0 polypropylene sutures with a long curved needle 1 mm posterior to the surgical limbus and found the mean SEQ error to be e0.65 D from the predicted target. Abbey et al15 reported refractive outcomes on a series of 22 eyes that
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Figure 3. Box-and-whisker plot showing that the mean surgically induced astigmatism was 0.770.65 diopter (D) for all eyes and was similar between the 2 different intraocular lens models. The mean surgically induced astigmatism was 0.730.59 D for the Akreos A060 lens and 0.580.71 D for the enVista MX60 lens (P ¼ 0.54).
Su et al
Refractive Outcomes with Scleral Sutured IOL
closer to plano for the 2-mm group than the 3-mm group. This is because of sulcus-based calculations when placing sclerotomies 2 mm posterior to the limbus, which typically involves reducing the in-the-bag IOL power by 0.5 to 1.0 D.16 Despite this adjustment, eyes with IOL fixation 2 mm posterior to the limbus ended up more myopic than those with fixation 3 mm posterior to the limbus, with a trend toward significance. This is likely because without data on refractive outcomes, surgeons were not as aggressive in reducing the IOL power for sulcus-based calculations to avoid hyperopic outcomes. Refractive outcomes for eyes with IOL fixation 3 mm posterior to the limbus were less than 0.5 D more myopic than the preoperative target based on in-the-bag calculations. Correlation analysis between the mean change in postoperative refraction compared with the preoperative target (DSEQ) and the axial length, corneal power, and IOL power did not reveal a significant relationship. It is possible that a relationship may be found with a larger sample size. For example, at the extreme ends of the spectrum (very short or very long eyes), fixation of the IOL at 3 mm posterior to the limbus may result in different refractive outcomes. However, this may be compensated for partially by using IOL formulas that more accurately predict the postoperative result. Surgically induced astigmatism at the corneal plane is determined by the size and location of the corneal incision. Clear corneal incisions in cataract surgery with phacoemulsification range from 2.2 to 4 mm.17,18 The amount of SIA may range from 0.24 to 1.65 D, depending on the size and location of the incision.18 In the current study, the mean SIA of 0.77 D was comparable with those found after cataract surgery with incisions of similar sizes.18 In addition to SIA at the corneal plane, scleral-fixated IOL may be more susceptible to lens tilt, which can induce astigmatism and higher-order aberrations.19 The Akreos A060 IOL theoretically decreases the risk of lens tilt and amount of induced astigmatism because of its 4-point fixation; however, the mean SIA was similar between the 2 IOL models in the current study. Further investigation with anterior segment OCT to quantify the amount of lens tilt between IOL models may be warranted. Our institution previously commented on the surgical learning curve encountered with new techniques and offered several suggestions to improve surgical performance.9,10 This article highlights the importance of consistency in sclerotomy site placement. To reduce chances of so-called refractive surprise, each sclerotomy site should be measured and marked to ensure an accurate and uniform distance from the limbus and each other. Small errors in sclerotomy placement can result in large variations in postoperative refractive outcome. Placing the sclerotomies more posterior than intended may result in a hyperopic outcome, whereas anterior placement may result in a myopic outcome and may increase the potential of iris chafing and ciliary body trauma. Appropriate suture tension also is critical. Too much suture laxity may result in lens movement and unpredictable refractive outcomes, whereas overly tight sutures may result in bending of the lens, resulting in irregular astigmatism. Because of these surgeon-dependent
factors, tracking of postoperative refractive outcomes is essential to refine individual surgical technique to produce more accurate results. This study has several limitations. Because of its retrospective nature, there may be a selection bias toward patients with more significant refractive errors because only patients with postoperative refractions were included. In addition, because the primary outcome in this study was refractive outcomes and not best-corrected visual acuity, we did not specifically exclude patients with a history of retinal pathologic features limiting visual acuity. However, patients who were unable to be refracted because of severe glaucomatous or retinal pathologic features were excluded from the study. In addition, the distance between sclerotomies (3e5 mm apart) was not included as a study variable. This is less likely to be a determining factor in postoperative refraction as long as appropriate suture tension is applied, but it is possible that variations in the distance between sclerotomies may affect the refractive outcome. Finally, we had a relatively small sample size of eyes in which MX60 IOLs were placed, which may have limited the power of analysis to detect significant differences in the amount of SIA between IOL models. In summary, we report postoperative refractive outcomes after combined PPV and scleral-fixated IOL with Gore-Tex suture. Mean postoperative SEQ was closer to the desired target when the IOL was placed 3 mm from the limbus compared with 2 mm from the limbus. These data may be useful for other surgeons performing this technique to understand how lens power calculations may be adjusted to refine the refractive outcome. References 1. Wagoner MD, Cox TA, Ariyasu RG, et al. Intraocular lens implantation in the absence of capsular support: a report by the American Academy of Ophthalmology. Ophthalmology. 2003;110:840e859. 2. Maggi R, Maggi C. Sutureless scleral fixation of intraocular lenses. J Cataract Refract Surg. 1997;23:1289e1294. 3. Prasad S. Transconjunctival sutureless haptic fixation of posterior chamber IOL: a minimally traumatic approach for IOL rescue or secondary implantation. Retina. 2013;33:657e660. 4. Prenner JL, Feiner L, Wheatley HM, Connors D. A novel approach for posterior chamber intraocular lens placement or rescue via a sutureless scleral fixation technique. Retina. 2012;32:853e855. 5. Todorich B, Thanos A, Woodward MA, Wolfe JD. Sutureless intrascleral fixation of secondary intraocular lens using 27gauge vitrectomy system. Ophthalmic Surg Lasers Imaging Retina. 2016;47:376e379. 6. Khan MA, Gerstenblith AT, Dollin ML, et al. Scleral fixation of posterior chamber intraocular lenses using Gore-Tex suture with concurrent 23-gauge pars plana vitrectomy. Retina. 2014;34:1477e1480. 7. Yamane S, Inoue M, Arakawa A, Kadonosono K. Sutureless 27-gauge needle-guided intrascleral intraocular lens implantation with lamellar scleral dissection. Ophthalmology. 2014;121:61e66. 8. Jacob S, Agarwal A, Agarwal A, et al. Glued capsular hook: technique for fibrin glue-assisted sutureless transscleral fixation of the capsular bag in subluxated cataracts and intraocular lenses. J Cataract Refract Surg. 2014;40:1958e1965.
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Ophthalmology Retina Volume 3, Number 7, July 2019 9. Khan MA, Samara WA, Gerstenblith AT, et al. Combined pars plana vitrectomy and scleral fixation of an intraocular lens using Gore-Tex suture: one-year outcomes. Retina. 2017;38: 1377e1384. 10. Khan MA, Gupta OP, Pendi K, et al. Pars plana vitrectomy with anterior chamber versus Gore-Tex sutured posterior chamber intraocular lens placement: long-term outcomes. Retina. 2019;39:860e866. 11. Mahmud I, Kelley T, Stowell C, et al. A proposed minimum standard set of outcome measures for cataract surgery. JAMA Ophthalmol. 2015;133:1247e1252. 12. Kalevar A, Dollin M, Gupta RR. Opacification of scleral-sutured Akreos A060 intraocular lens after vitrectomy with gas tamponade: case series. Retin Cases Brief Rep. 2017. In Press. 13. Hoffer KJ. Clinical results using the Holladay 2 intraocular lens power formula. J Cataract Refract Surg. 2000;26: 1233e1237. 14. Hayashi K, Hayashi H, Nakao F, Hayashi F. Intraocular lens tilt and decentration, anterior chamber depth, and refractive
15.
16. 17. 18.
19.
error after trans-scleral suture fixation surgery. Ophthalmology. 1999;106:878e882. Abbey AM, Hussain RM, Shah AR, et al. Sutureless scleral fixation of intraocular lenses: outcomes of two approaches. The 2014 Yasuo Tano Memorial Lecture. Graefes Arch Clin Exp Ophthalmol. 2015;253:1e5. Dubey R, Birchall W, Grigg J. Improved refractive outcome for ciliary sulcus-implanted intraocular lenses. Ophthalmology. 2012;119:261e265. Can I, Takmaz T, Yildiz Y, et al. Coaxial, microcoaxial, and biaxial microincision cataract surgery: prospective comparative study. J Cataract Refract Surg. 2010;36:740e746. Theodoulidou S, Asproudis I, Athanasiadis A, et al. Comparison of surgically induced astigmatism among different surgeons performing the same incision. Int J Ophthalmol. 2017;10:1004e1007. Stem MS, Todorich B, Woodward MA, et al. Scleral-fixated intraocular lenses: past and present. J Vitreoretin Dis. 2017;1: 144e152.
Footnotes and Financial Disclosures Originally received: September 27, 2018. Final revision: February 8, 2019. Accepted: February 19, 2019. Available online: March 2, 2019. Manuscript no. ORET_2018_407. 1
Retina Service, Wills Eye Hospital, Philadelphia, Pennsylvania.
2
Accountability (HIPAA) Act of 1996 and adhered to the tenets of the Declaration of Helsinki. No animal subjects were included in this study. Author Contributions: Conception and design: Su, Obeid, Khan, Hsu, Garg, Gupta.
Retina Division, Doheny and Stein Eye Institutes, David Geffen School of Medicine at UCLA, Los Angeles, California.
Analysis and interpretation: Su, Stephens, Obeid, Hsu, Garg, Gupta.
Presented at: Retina Society Annual Meeting, September 2018, San Francisco, California.
Obtained funding: N/A
Financial Disclosure(s): The author(s) have made the following disclosure(s): M.A.K.: Financial support e Allergan. J.H.: Consultant e UCB (Brussels, Belgium); Financial support e Roche/ Genentech, Santen, Ophthotech. S.J.G.: Consultant e Deciphera, Santen, Bausch and Lomb, Topivert; Financial support e Aerpio, Allergan, Eyegate, Apellis. HUMAN SUBJECTS: Human subjects were included in this study. The institutional review board at Wills Eye Hospital approved the study. Informed consent was waived by the IRB due to the retrospective nature of the study. All research complied with the Health Insurance Portability and
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Data collection: Su, Stephens, Obeid, Borkar, Storey, Khan. Overall responsibility: Su, Stephens, Obeid, Borkar, Storey, Khan, Hsu, Garg, Gupta. Abbreviations and Acronyms: D ¼ diopter; IOL ¼ intraocular lens; PPV ¼ pars plana vitrectomy; SEQ ¼ spherical equivalent; SIA ¼ surgically induced astigmatism; DSEQ ¼ difference in spherical equivalent. Correspondence: Omesh Gupta, MD, Retina Service, Wills Eye Hospital, Mid Atlantic Retina, 840 Walnut Street, Suite 1020, Philadelphia, PA 19107. E-mail: [email protected].