- Email: [email protected]
Retinal detachment after clear lens extraction for high myopia
Retinal Detachment after Clear Lens Extraction for High Myopia Seven-year Follow-up Joseph Colin, MD, Anne Robinet, MD, Be´atrice Cochener, MD Objective: To prospectively evaluate the incidence of complications, particularly retinal detachment, 7 years after clear lens extraction (CLE) for myopia greater than ⫺12 diopters (D). Design: Extended follow-up of noncomparative case series. Participants: Fifty-two eyes of 30 patients with preoperative myopia greater than ⫺12 D, best-corrected visual acuity (BCVA) of 20/100 or better, and intolerance of contact lenses. Intervention: Patients with lattice degeneration, retinal tear, or hole underwent photocoagulation before CLE. The authors performed phacoemulsification through a 3.2-mm-wide incision using primary irrigation and aspiration, widened the incision to 6.5 mm, and implanted a one-piece polymethyl methacrylate intraocular lens (IOL). Main Outcome Measures: The BCVA, uncorrected visual acuity (UCVA), stability of spherical equivalent (SE), neodymium:YAG (Nd:YAG) capsulotomy rate, and complications (especially retinal detachment). Results: At 7 years, the SEs of 29 eyes (59.1%) were within ⫾1.0 D of emmetropia and 42 eyes (85.7%) were within ⫾2.0 D. Mean SE was ⫺1.01 D (⫾0.94). At 7 years, mean UCVA was 20/80 compared with 20/66 at 1 year. BCVA and UCVA were better in eyes with open capsules versus intact capsules. During the 7 years, 30 eyes (61.2%) required capsulotomy for opacification. Mean time for capsulotomy was 48.4 months after CLE. The authors performed ten argon laser retinal treatments after surgery, with all but one in the first postoperative year. The overall incidence of posterior vitreous detachment was 16.3%. The incidence of retinal detachment during the 7 years was 4 of 49 eyes, or 8.1% (vs. 2.0% at 4 years). One patient had bilateral retinal detachments. Conclusion: Despite advances in surgical technique, retinal detachment remains a major concern after CLE for high myopia. In the authors’ series, the incidence of retinal detachment after CLE was nearly double that estimated for persons with myopia greater than ⫺10 D who do not undergo surgery. Although CLE has advantages, including rapid and predictable visual rehabilitation, stable refraction, the ability to replace the IOL, and often superb optical quality with no irregular astigmatism, it is invasive and can result in severe vision loss. Long and continuous follow-up of the outcomes of CLE for high myopia is absolutely necessary before the authors can consider CLE as a routine option for patients with high myopia. Ophthalmology 1999;106:2281–2285 Removal of the clear crystalline lens may be considered for high myopia and hyperopia1 in bilateral cases or in anisometropia with relative amblyopia. For patients with high myopia, clear lens extraction (CLE) remains one of the most controversial refractive procedures. CLE is technically easy to perform and effective when followed by implantation of a low or negative power intraocular lens (IOL). CLE can provide rapid and predictable visual rehabilitation and stable refraction, and the implant can be removed and replaced, usually easily and safely, in the rare case of refractive surprise. Further, the quality of optical rehabilitation is superb; there is no irregular
Originally received: November 10, 1998. Revision accepted: August 3, 1999. Manuscript no. 98522. From the Department of Ophthalmology, Brest University Hospital, Brest, France. Presented in part at the American Academy of Ophthalmology annual meeting, New Orleans, Louisiana, November 1998. Reprint requests to Joseph Colin, MD, Brest University Hospital, Department of Ophthalmology, Hoˆpital Morvan, 5 Avenue Foch, 29200 Brest, France.
astigmatism and resolution is high. However, CLE is an invasive procedure that can result in severe vision loss. Albeit rare, the primary risk is an increased potential for retinal detachment. Other potential complications include cystoid macular edema and endophthalmitis. Despite these severe complications, advances in surgical technique have led us to reconsider this option and to weigh the risks against the benefits of the procedure. We previously reported the 1- and 4-year results of a prospective study of retinal detachment after prophylaxis, CLE, and posterior chamber IOL implantation.2,3 In this article, we present the 7-year results of this study.
Methods From January 1990 through June 1991, 52 eyes of 30 patients were entered into the study. The detailed study design, patient selection methods, surgical procedure, and 2- and 4-year results have been published.2,3 A brief review of the methods follows. We selected patients based on preoperative myopia of greater than ⫺12 diopters (D), best-corrected visual acuity (BCVA) of
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Ophthalmology Volume 106, Number 12, December 1999 Table 1. Visual Results of Eyes with Retinal Detachment (RD)
Age at time of surgery (yrs) Sex Preoperative myopia (D) Axial length (mm) Argon laser Nd:YAG/postoperative interval Time of RD RD location RD quadrants Macular status No. of RD surgical procedures Final visual outcome (BCVA)
Case 1
Case 2*
Case 3*
Case 4
30 Male ⫺20 31 Yes No 18 mos Temporal ⫹ inf-nasal 3 Detached 3 20/200
39 Male ⫺12 28.5 No Yes/4 yrs 6 yrs Temporal 2 Detached 1 20/50 (20/40 before RD) 20/100 (20/100 before RD)
39 Male ⫺12.50 29.5 No Yes/4 yrs 6 yrs Nasal 2 Intact 1 20/100 (20/100 before RD) 20/50 (20/40 before RD)
38 Male ⫺15 29.5 No Yes/4.5 yrs 5.5 yrs Temporal ⫹ inf-nasal 3 Detached 1 20/30 20/25 before RD 20/30
Status of fellow eye
20/40
BCVA ⫽ best corrected visual acuity. * Same patient (bilateral retinal detachments).
20/100 or better, and intolerance of contact lenses. We obtained informed consent from all patients before surgery. Patients with prior retinal detachment or glaucoma were excluded. In patients with lattice degeneration, retinal tear, or hole, we performed argon laser photocoagulation before CLE. We used focal treatment for small lesions and circumferential treatment for diffuse degeneration. Direct argon green-laser retinal photocoagulation was performed 2 months before CLE using 100 to 200 mW, 500 m, 0.1-second retinal spots. Three rows of nearly confluent burns were placed immediately around focal lesions. When a circumferential laser photocoagulation was required, four sessions were necessary to obtain the 360° retinal treatment. Radial extensions were performed anterior to the ora serrata in the horizontal and vertical meridians. For lens extraction, we performed phacoemulsification through a 3.2-mm-wide incision. Because of lens softness, we used primary irrigation and aspiration. We then widened the incision to 6.5 mm and implanted an AMO PC25NB one-piece polymethyl methacrylate IOL (Allergan, Irvine, CA). Patients were asked to return for retinal examination annually. We performed argon laser photocoagulation for new retinal lesions. We postponed the neodymium:YAG (Nd:YAG) capsulotomy until absolutely necessary. When needed, we performed a small, precise capsulotomy of 4 mm. The 7-year postoperative evaluation included slit-lamp examination, evaluation of complications including posterior vitreous detachment (using a ⫹90-D lens and a Goldmann three-mirror contact lens), recording of additional procedures including Nd:YAG capsulotomy, detailed evaluation of the retina by a retinal specialist (AR), intraocular pressure (IOP) measurement, and uncorrected visual acuity (UCVA), BCVA, and refractive evaluations.
At 7 years, the SEs of 29 eyes (59.1%) were within ⫾1.0 D of emmetropia and 42 eyes (85.7%) were within ⫾2.0 D. Mean SE was ⫺1.01 D (⫾0.94). At 7 years, five eyes had experienced a myopic shift between ⫺0.50 D and ⫺2.0 D. At 7 years, 83.3% of eyes with posterior capsulotomies had distance BCVA of 20/40 or better. Only 54.8% of eyes with intact posterior capsules had distance BCVA of 20/40 or better. Table 1 lists the visual acuity of eyes that underwent retinal detachment surgery. Overall, two eyes had a BCVA decrease greater than two lines, one after macular complications and one after retinal detachment. At 7 years, mean UCVA was 0.25 (20/80) compared with 0.30 (20/66) at 1 year. Mean UCVA was 0.34 in eyes with open posterior capsules and 0.20 in eyes with intact capsules. Just more than 65% of eyes achieved 20/100 or better UCVA at 7 years compared with 84.6% at 1 year; 83.3% of eyes with open capsules and 54.8% of eyes with intact capsules achieved UCVA of 20/100 or better at 7 years.
Nd:YAG Capsulotomies During the first 4 postoperative years, 18 eyes (36.7%) required Nd:YAG capsulotomy for posterior capsule opacification. Mean time for capsulotomy was 19.6 months after CLE (⫾6.9; range, 9 –33 months). There were no early complications resulting from capsulotomy. In three eyes, the capsulotomy was too small, and we performed secondary enlargements. During the 7-year follow-up period, 30 eyes (61.2%) required capsulotomy for posterior capsule opacification. Mean time for capsulotomy was 48.4 months after CLE (range, 9 –75 months).
Intraocular Pressure
Results Forty-nine eyes (28 patients) were available for the 7-year evaluation. Two patients were lost to follow-up.
Refractive and Visual Results The mean preoperative spherical equivalent (SE) was ⫺16.9 D (⫾3.26). Axial length was greater than 29 mm in 64% of eyes, and 15.3% of the IOLs were minus powered.
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Throughout the 7-year follow-up period, IOP was less than 20 mmHg in all eyes.
Retinal Treatments/Complications Argon Laser Retinal Treatment. Before surgery, 19 eyes underwent focal photocoagulation, 12 eyes had circumferential photocoagulation, and 21 eyes did not have any treatment. During the first postoperative year, we performed seven additional focal treatments and two additional circumferential treatments. At 4 years,
Colin et al 䡠 Clear Lens Extraction one eye that did not receive a preoperative argon laser treatment required focal treatment for lattice degeneration. Between postoperative years 4 and 7, we did not perform any further retinal treatments. Macular Complications. At 9 months, a subfoveal choroidal neovascularization developed in one eye. Distance BCVA, which was 20/50 before and after surgery before this complication, decreased to 20/200 and near-BCVA decreased from Parinaud 2 to Parinaud 4. There were no new macular complications during the remainder of the 7-year follow-up period. Posterior Vitreous Detachment. Before surgery, the incidence of posterior vitreous detachment (PVD) was 57.7%, and PVD was more prevalent in older eyes. We detected two new cases of PVD during the first postoperative year and two additional cases by the fourth year. No other complications occurred in these four eyes. By the seventh postoperative year, we observed four additional cases of PVD (overall postoperative incidence, 16.3%). Retinal Detachment. During the 7 years of follow-up, retinal detachment occurred in four eyes (8.1%). The characteristics of these eyes are listed in Table 1. We observed one case of retinal detachment 18 months after surgery in a 30-year-old woman with a preoperative myopia of ⫺20 D and an axial length of 31 mm. Her posterior capsule was intact; the peripheral retina had been treated before surgery at another hospital. The retinal tear occurred in an area outside the treated quadrant. Three surgical procedures were necessary to reattach the retina. Her final BCVA was 20/200 because of chronic macular edema. The fellow eye, which was also treated by CLE for myopia, did not show any signs of peripheral retinal degeneration. The three additional retinal detachments occurred between 4 and 7 years after surgery in two patients (one bilateral case). The second case occurred in a 39-year-old man 6 years after CLE. The retinal examination showed two large equatorial horseshoe tears with posterior extension. Treatment included 360° scleral buckling of the vitreous base, liquid perfluorocarbon endocular argon laser photocoagulation around the tears, and longacting gas for tamponade (perfluoropropane gas in nonexpansial concentration). The retina was reattached with a good visual outcome (Table 1). One month after this retinal detachment, a similar complication occurred in the fellow eye before a planned retinal prophylactic treatment. We observed the same pattern (two equatorial tears). The surgical retinal procedure was the same as in the fellow eye; the retina was reattached with no loss of BCVA. The fourth retinal detachment occurred in a 38-year-old man who presented with two horseshoe tears in the temporal superior quadrant. One external procedure including cryoapplication with scleral buckling was sufficient to reattach the retina. Although others believe it is imperative to remove the IOL when retinal detachment occurs because it hinders visualization of the peripheral retina,4 we performed surgery without removing the IOL in all three retinal detachments that were managed in our department with good anatomic and functional results. The problem of hindered vision may stem, in part, from condensation on silicone IOLs, which has been reported to interfere with the surgeon’s view of the retina during a posterior segment fluid–air exchange procedure.5,6 The use of silicone oil may also induce similar side effects.5,6
Discussion A century ago, Fukala7,8 began treating high myopia by removing the clear lens, and although the refractive results were acceptable, severe perioperative and postoperative complications were common. The beginning of the modern
era of lens implant surgery for myopia, by Barraquer,9 was also marked by frequent inflammatory and corneal complications. Today, thanks to phacoemulsification, small incision surgery, posterior chamber IOLs, and viscoelastics, CLE is being considered more and more for the treatment of both high myopia and hyperopia. Werblin10 has even asked whether CLE should be considered “routine refractive surgery.” Still, serious questions remain about the risk:benefit ratio of CLE. There is no question that intraocular surgery using current techniques increases the risk of visual loss. Perkins11 estimated the incidence of retinal detachment in the unoperated patient population with myopia greater than ⫺10 D to be 0.68% annually, or 4.76% over 7 years. In our study, the 7-year incidence of retinal detachment after CLE in eyes with preoperative myopia greater than ⫺12 D was nearly double (8.1%). In other current clinical studies with follow-up of 15 months to 7 years, the reported risk of retinal detachment after CLE in highly myopic eyes varied from 0% to 9.2%.12–16 Lee and Lee12 followed 24 eyes for 15 months after CLE for mean myopia of ⫺16.6 D (⫾1.6) and observed no retinal detachments. Similarly, Jimenez–Alfaro et al13 reported no retinal detachments 12 to 26 months after CLE in 26 eyes with mean preoperative myopia of ⫺20.8 D (⫾5.4). In their series of 31 eyes with mean myopia of ⫺12.0 D (⫾2.9) treated with CLE via phacoemulsification, Lyle and Jin14 reported no retinal detachments after a mean follow-up of 20 months. Centurion et al also reported a zero incidence of retinal detachment after 7 years in their series of 35 highly myopic eyes (mean myopia, ⫺16.5 D ⫾ 5.7) that underwent prophylactic treatment of the peripheral retina and CLE (unpublished data, 1999). In their series of 46 CLEs for high myopia (mean myopia, ⫺16.05 D ⫾ 5.01) with 15 months of follow-up, Gris et al15 reported 1 retinal detachment (2.2%) that occurred 4 weeks after surgery in an eye with a posterior capsular tear. In their retrospective evaluation of 165 eyes with axial length greater than 26 mm and/or aphakic refractive sphere of 8 D or less treated with manual extracapsular and intracapsular CLE (10 that also received argon laser prophylaxis), Barraquer et al16 found a 7.3% incidence of retinal detachment. Retinal detachment occurred an average of 30.7 months (⫾26.6 months) after surgery, with half occurring during the first 2 postoperative years. Only 15% of patients received an IOL, and the retina was reattached in 75% of cases. Barraquer et al found an association between retinal detachment and YAG capsulotomy in this series. In these studies, the risk of retinal detachment may have been related to surgical technique, degree of preoperative myopia, and duration of follow-up. Interestingly, studies with a follow-up of 4 years or less tended to have excellent results, suggesting that the risk of retinal detachment may increase with time. In our series, three of the four retinal detachments occurred between postoperative years 4 and 7. It is not clear whether argon laser prophylaxis helps reduce the incidence of retinal detachment after CLE, but it is evident that prophylactic treatment does not always prevent late retinal detachment after CLE. In our study, one eye developed retinal detachment after argon laser prophylaxis, and three eyes that
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Ophthalmology Volume 106, Number 12, December 1999 did not receive prophylactic treatment developed retinal detachment. In the review by Ripandelli et al17 of 41 retinal detachments that occurred 1 month to 4 years after CLE, 26 eyes (63.4%) underwent 360° prophylactic retinopexy on preequatorial areas. Further, some authors contend that the severity of retinal detachment may be greater when it occurs after argon laser treatment.17,18 From our study, there is no way to determine whether the prophylaxis treatment method influenced the risk of retinal detachment. However, the fact that the one eye in our study with both prophylaxis and retinal detachment had the poorest results raises the question of a possible correlation. In their review, Ripandelli et al17 reported that retinal breaks occurred along the edge of the photocoagulation in 4 of the 26 eyes that underwent retinopexy. In our study, the prophylactically treated eye that developed retinal detachment developed a tear outside the treated quadrant, although this does not preclude a correlation between the prophylaxis method and the clinical outcome. To determine whether an 8.1% risk of retinal detachment at 7 years is acceptable, we must also consider our ability to achieve other important goals of CLE in the patients with high myopia, such as good visual results and a low rate of other complications.
Visual Results Our series, using modern surgical techniques for CLE and prophylactic retinal treatment, confirms that the good refractive results obtained at 1 year remain relatively stable over the 7 years. Although UCVA did worsen most significantly in eyes with intact posterior capsules, it is important to remember that cataracts develop earlier in unoperated eyes with high myopia than in the nonmyopic unoperated population. Further, in our series, only one of the four eyes with retinal detachment developed a loss of BCVA greater than two lines. Although the risk of visual loss from intraocular surgery is greater than that from refractive corneal surgery, it is worth noting that the risk of visual loss after corneal surgery is not insignificant. Retinal detachment has been reported after laser in situ keratomileusis.19 Further, most of the visual side effects of corneal refractive surgery—variable visual acuity, starbursting effects— do not occur with CLE because the cornea remains intact.
Other Complications Both CLE and Nd:YAG capsulotomy in highly myopic eyes increase the incidence of PVD, and these vitreous changes may predispose the patient to retinal degeneration and retinal detachment. In addition, in our study, one eye developed subfoveal choroidal neovascularization, but it is unclear whether there is a potential increased risk of macular neovascular complications after CLE. The main limitation of our prospective series is size; the numbers are relatively small and the statistics are therefore fragile. Still, these data show that the primary concern about CLE in patients with high myopia remains the inevitable vitreoretinal degeneration that can ultimately lead to retinal detachment. As Goldberg20 has pointed out, CLE usually needs to be bilateral to avoid substantial aniseikonia, and this places both eyes at risk. Further follow-up of eyes
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undergoing late posterior capsulotomy is also important; opacification of the posterior capsule is not yet preventable. Long and continuous follow-up of the outcomes of CLE for high myopia is absolutely necessary before we can even consider this surgical procedure as a routine option.
References 1. Siganos DS, Pallikaris IG, Siganos CS. Clear lensectomy and intraocular lens implantation in normally sighted highly hyperopic eyes. Three-year follow-up. Eur J Implant Refract Surg 1995;7:128 –33. 2. Colin J, Robinet A. Clear lensectomy and implantation of low-power posterior chamber intraocular lens for the correction of high myopia. Ophthalmology 1994;101:107–12. 3. Colin J, Robinet A. Clear lensectomy and implantation of a low-power posterior chamber intraocular lens for correction of high myopia. A four-year follow-up. Ophthalmology 1997; 104:73– 8. 4. Batman C, Cekic O. Clear lensectomy and implantation of IOL for high myopia [letter]. Ophthalmology 1998;105:944 –5. 5. Hainsworth DP, Chen SN, Cox TA, Jaffe GJ. Condensation on polymethylmethacrylate, acrylic polymer, and silicone intraocular lenses after fluid-air exchange in rabbits. Ophthalmology 1996;103:1410 – 8. 6. Khawly JA, Lambert RJ, Jaffe GJ. Intraocular lens changes after short- and long-term exposure to intraocular silicone oil. An in vivo study. Ophthalmology 1998;105:1227–33. 7. Fukala V. Operative Behandlung der ho¨chstgradigen Myopie durch Aphakie. Albrecht von Graefes Arch Ophthalmol 1890; 36:230 – 44. 8. Fukala V. Bietrag sur hochgradigen myopie. Ber Dtsch Ophtal Ges 1896;25:265. 9. Barraquer J. La extraccion intracapsular del cristalino: Ponencia oficial del XL Congresso de la Sociedad Hispanoamericana de Grande Espana, 1962. Barcelona, Spain, Graficas Typus 1961;39. 10. Werblin TP. Should we consider clear lens extraction for routine refractive surgery? Refract Corneal Surg 1992;8:480 –1. 11. Perkins ES. Morbidity from myopia. Sight Saving Review 1979;49:11–9. 12. Lee KH, Lee JH. Long-term results of clear lens extraction for severe myopia. J Cataract Refract Surg 1996;22:1411–5. 13. Jimenez–Alfaro I, Miguelez S, Bueno JL, Puy P. Clear lens extraction and implantation of negative-power posterior chamber intraocular lenses to correct extreme myopia. J Cataract Refract Surg 1998;24:1310 – 6. 14. Lyle WA, Jin GJC. Clear lens extraction for the correction of high refractive error. J Cataract Refract Surg 1994;20:273– 6. 15. Gris O, Gu¨ell JL, Manero F, Mu¨ller A. Clear lens extraction to correct high myopia. J Cataract Refract Surg 1996;22:686 –9. 16. Barraquer C, Cavelier C, Mejia LF. Incidence of retinal detachment following clear-lens extraction in myopic patients. Arch Ophthalmol 1994;112:336 –9. 17. Ripandelli G, Billi B, Fedeli R, Stirpe M. Retinal detachment after clear lens extraction in 41 eyes with high axial myopia. Retina 1996;16:3– 6. 18. Bonnet M, Aracil P, Carneau F. Rhegmatogenous retinal detachment after prophylactic argon laser photocoagulation. Graefes Arch Clin Exp Ophthalmol 1987;225:5– 8. 19. Ozdamar A, Aras C, Sener B. Bilateral retinal detachment associated with giant retinal tear after laser-assisted in situ keratomileusis. Retina 1998;18:176 –7. 20. Goldberg MF. Clear lens extraction for axial myopia. An appraisal. Ophthalmology 1987;94:571– 82.
Colin et al 䡠 Clear Lens Extraction Discussion by Mario Stirpe, MD Clear lens extraction to correct axial myopia remains a very controversial technique because of the high risk of retinal detach1–3 ment (RD) and severe visual loss. The study by Colin and 4,5 Robinet was designed to prospectively evaluate the incidence of retinal detachment in eyes with myopia of 12 diopters or more, in which clear lens extraction (CLE) and posterior chamber intraocular lens implantation were performed to correct axial myopia. This is the third in a series of reports from these authors4,5 and shows that after several years of follow-up, a gradual increase in the incidence of vitreoretinal complications after CLE occurs over time. The clinical and historical details of the patients were not provided but are available in a previous report on this cohort.4 The value of the current study arises from the long-term follow-up after CLE. Criticisms that may arise from this study will involve the lack of discussion of (1) the possible effect of the prophylactic laser photocoagulation on the incidence of RD; (2) the effect of yttrium– aluminum– garnet (YAG)-laser capsulotomy on the incidence of RD; and (3) the importance of vitreous changes after CLE. In particular, references to points (1) and (2) are provided, but the authors do not comment on their own results. Regarding point (3), the authors reported in a previous article an incidence of preoperative posterior vitreous detachment (PVD) ranging from 40% to 71% depending on the age of the patients, but no mention is made of the preoperative condition of the vitreous in those eyes that developed RD. In a study by Ripandelli and colleagues6 on 49 eyes (of 47 patients) that underwent surgery for RD after CLE, the fellow eyes were examined. In six of these fellow eyes without RD, but which had also undergone CLE, important modifications of the vitreous were present. Conversely, no vitreous changes were detected in the 39 eyes that did not undergo CLE. Thus, Ripandelli and colleagues suggested that CLE in young subjects might play a major role in RD by precipitating vitreous changes that otherwise would have occurred more slowly over time.
From Fondazione G. B. Bietti per lo studio e la ricerca in oftalmologia, Piazza Sassari, 5, 00161 Roma, Italy. E-mail: [email protected].
We would also stress that vitreous gel in highly myopic eyes is often characterized by structural changes such as extensive vitreous liquefaction and posterior vitreous schisis.7 These changes are quite different from the more common PVD8 and should be evaluated carefully not only in relation to the lens extraction but also to prophylactic laser photocoagulation, which may induce unpredictable effects. In conclusion, although the current study was performed on a small sample, it presents important information on the long-term incidence of vitreoretinal complications after CLE. Certainly, in the future, more insight into the pathophysiology of vitreoretinal complications will be gained, as well as greater knowledge of vitreoretinal relationships and postoperative changes. References 1. Goldberg MF. Clear lens extraction for axial myopia. An appraisal. Ophthalmology 1987;94:571– 82. 2. Barraquer C, Cavalier C, Mejia LF. Incidence of retinal detachment following clear-lens extraction in myopic patients. Arch Ophthalmol 1994;112:336 –9. 3. Javitt JC. Clear-lens extraction for high myopia. Is this an idea whose time has come? Arch Ophthalmol 1994;112:321–3. 4. Colin J, Robinet A. Clear lensectomy and implantation of low-power posterior chamber intraocular lens for the correction of high myopia. Ophthalmology 1994;101:107–12. 5. Colin J, Robinet A. Clear lensectomy and implantation of a low-power posterior chamber intraocular lens for the correction of high myopia. A four-year follow-up. Ophthalmology 1997;104:73– 8. 6. Ripandelli G, Billi B, Fedeli R, Stirpe M. Retinal detachment after clear lens extraction in 41 eyes with high axial myopia. Retina 1996;16:3– 6. 7. Sebag J. The Vitreous: Structure, Function, and Pathobiology. New York: Springer–Verlag, 1989;86 –7. 8. Stirpe M, Heimann K. Vitreous changes and retinal detachment in highly myopic eyes. Eur J Ophthalmol 1996;6: 50 – 8.
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Originally received: November 10, 1998. Revision accepted: August 3, 1999. Manuscript no. 98522. From the Department of Ophthalmology, Brest University Hospital, Brest, France. Presented in part at the American Academy of Ophthalmology annual meeting, New Orleans, Louisiana, November 1998. Reprint requests to Joseph Colin, MD, Brest University Hospital, Department of Ophthalmology, Hoˆpital Morvan, 5 Avenue Foch, 29200 Brest, France.
astigmatism and resolution is high. However, CLE is an invasive procedure that can result in severe vision loss. Albeit rare, the primary risk is an increased potential for retinal detachment. Other potential complications include cystoid macular edema and endophthalmitis. Despite these severe complications, advances in surgical technique have led us to reconsider this option and to weigh the risks against the benefits of the procedure. We previously reported the 1- and 4-year results of a prospective study of retinal detachment after prophylaxis, CLE, and posterior chamber IOL implantation.2,3 In this article, we present the 7-year results of this study.
Methods From January 1990 through June 1991, 52 eyes of 30 patients were entered into the study. The detailed study design, patient selection methods, surgical procedure, and 2- and 4-year results have been published.2,3 A brief review of the methods follows. We selected patients based on preoperative myopia of greater than ⫺12 diopters (D), best-corrected visual acuity (BCVA) of
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Ophthalmology Volume 106, Number 12, December 1999 Table 1. Visual Results of Eyes with Retinal Detachment (RD)
Age at time of surgery (yrs) Sex Preoperative myopia (D) Axial length (mm) Argon laser Nd:YAG/postoperative interval Time of RD RD location RD quadrants Macular status No. of RD surgical procedures Final visual outcome (BCVA)
Case 1
Case 2*
Case 3*
Case 4
30 Male ⫺20 31 Yes No 18 mos Temporal ⫹ inf-nasal 3 Detached 3 20/200
39 Male ⫺12 28.5 No Yes/4 yrs 6 yrs Temporal 2 Detached 1 20/50 (20/40 before RD) 20/100 (20/100 before RD)
39 Male ⫺12.50 29.5 No Yes/4 yrs 6 yrs Nasal 2 Intact 1 20/100 (20/100 before RD) 20/50 (20/40 before RD)
38 Male ⫺15 29.5 No Yes/4.5 yrs 5.5 yrs Temporal ⫹ inf-nasal 3 Detached 1 20/30 20/25 before RD 20/30
Status of fellow eye
20/40
BCVA ⫽ best corrected visual acuity. * Same patient (bilateral retinal detachments).
20/100 or better, and intolerance of contact lenses. We obtained informed consent from all patients before surgery. Patients with prior retinal detachment or glaucoma were excluded. In patients with lattice degeneration, retinal tear, or hole, we performed argon laser photocoagulation before CLE. We used focal treatment for small lesions and circumferential treatment for diffuse degeneration. Direct argon green-laser retinal photocoagulation was performed 2 months before CLE using 100 to 200 mW, 500 m, 0.1-second retinal spots. Three rows of nearly confluent burns were placed immediately around focal lesions. When a circumferential laser photocoagulation was required, four sessions were necessary to obtain the 360° retinal treatment. Radial extensions were performed anterior to the ora serrata in the horizontal and vertical meridians. For lens extraction, we performed phacoemulsification through a 3.2-mm-wide incision. Because of lens softness, we used primary irrigation and aspiration. We then widened the incision to 6.5 mm and implanted an AMO PC25NB one-piece polymethyl methacrylate IOL (Allergan, Irvine, CA). Patients were asked to return for retinal examination annually. We performed argon laser photocoagulation for new retinal lesions. We postponed the neodymium:YAG (Nd:YAG) capsulotomy until absolutely necessary. When needed, we performed a small, precise capsulotomy of 4 mm. The 7-year postoperative evaluation included slit-lamp examination, evaluation of complications including posterior vitreous detachment (using a ⫹90-D lens and a Goldmann three-mirror contact lens), recording of additional procedures including Nd:YAG capsulotomy, detailed evaluation of the retina by a retinal specialist (AR), intraocular pressure (IOP) measurement, and uncorrected visual acuity (UCVA), BCVA, and refractive evaluations.
At 7 years, the SEs of 29 eyes (59.1%) were within ⫾1.0 D of emmetropia and 42 eyes (85.7%) were within ⫾2.0 D. Mean SE was ⫺1.01 D (⫾0.94). At 7 years, five eyes had experienced a myopic shift between ⫺0.50 D and ⫺2.0 D. At 7 years, 83.3% of eyes with posterior capsulotomies had distance BCVA of 20/40 or better. Only 54.8% of eyes with intact posterior capsules had distance BCVA of 20/40 or better. Table 1 lists the visual acuity of eyes that underwent retinal detachment surgery. Overall, two eyes had a BCVA decrease greater than two lines, one after macular complications and one after retinal detachment. At 7 years, mean UCVA was 0.25 (20/80) compared with 0.30 (20/66) at 1 year. Mean UCVA was 0.34 in eyes with open posterior capsules and 0.20 in eyes with intact capsules. Just more than 65% of eyes achieved 20/100 or better UCVA at 7 years compared with 84.6% at 1 year; 83.3% of eyes with open capsules and 54.8% of eyes with intact capsules achieved UCVA of 20/100 or better at 7 years.
Nd:YAG Capsulotomies During the first 4 postoperative years, 18 eyes (36.7%) required Nd:YAG capsulotomy for posterior capsule opacification. Mean time for capsulotomy was 19.6 months after CLE (⫾6.9; range, 9 –33 months). There were no early complications resulting from capsulotomy. In three eyes, the capsulotomy was too small, and we performed secondary enlargements. During the 7-year follow-up period, 30 eyes (61.2%) required capsulotomy for posterior capsule opacification. Mean time for capsulotomy was 48.4 months after CLE (range, 9 –75 months).
Intraocular Pressure
Results Forty-nine eyes (28 patients) were available for the 7-year evaluation. Two patients were lost to follow-up.
Refractive and Visual Results The mean preoperative spherical equivalent (SE) was ⫺16.9 D (⫾3.26). Axial length was greater than 29 mm in 64% of eyes, and 15.3% of the IOLs were minus powered.
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Throughout the 7-year follow-up period, IOP was less than 20 mmHg in all eyes.
Retinal Treatments/Complications Argon Laser Retinal Treatment. Before surgery, 19 eyes underwent focal photocoagulation, 12 eyes had circumferential photocoagulation, and 21 eyes did not have any treatment. During the first postoperative year, we performed seven additional focal treatments and two additional circumferential treatments. At 4 years,
Colin et al 䡠 Clear Lens Extraction one eye that did not receive a preoperative argon laser treatment required focal treatment for lattice degeneration. Between postoperative years 4 and 7, we did not perform any further retinal treatments. Macular Complications. At 9 months, a subfoveal choroidal neovascularization developed in one eye. Distance BCVA, which was 20/50 before and after surgery before this complication, decreased to 20/200 and near-BCVA decreased from Parinaud 2 to Parinaud 4. There were no new macular complications during the remainder of the 7-year follow-up period. Posterior Vitreous Detachment. Before surgery, the incidence of posterior vitreous detachment (PVD) was 57.7%, and PVD was more prevalent in older eyes. We detected two new cases of PVD during the first postoperative year and two additional cases by the fourth year. No other complications occurred in these four eyes. By the seventh postoperative year, we observed four additional cases of PVD (overall postoperative incidence, 16.3%). Retinal Detachment. During the 7 years of follow-up, retinal detachment occurred in four eyes (8.1%). The characteristics of these eyes are listed in Table 1. We observed one case of retinal detachment 18 months after surgery in a 30-year-old woman with a preoperative myopia of ⫺20 D and an axial length of 31 mm. Her posterior capsule was intact; the peripheral retina had been treated before surgery at another hospital. The retinal tear occurred in an area outside the treated quadrant. Three surgical procedures were necessary to reattach the retina. Her final BCVA was 20/200 because of chronic macular edema. The fellow eye, which was also treated by CLE for myopia, did not show any signs of peripheral retinal degeneration. The three additional retinal detachments occurred between 4 and 7 years after surgery in two patients (one bilateral case). The second case occurred in a 39-year-old man 6 years after CLE. The retinal examination showed two large equatorial horseshoe tears with posterior extension. Treatment included 360° scleral buckling of the vitreous base, liquid perfluorocarbon endocular argon laser photocoagulation around the tears, and longacting gas for tamponade (perfluoropropane gas in nonexpansial concentration). The retina was reattached with a good visual outcome (Table 1). One month after this retinal detachment, a similar complication occurred in the fellow eye before a planned retinal prophylactic treatment. We observed the same pattern (two equatorial tears). The surgical retinal procedure was the same as in the fellow eye; the retina was reattached with no loss of BCVA. The fourth retinal detachment occurred in a 38-year-old man who presented with two horseshoe tears in the temporal superior quadrant. One external procedure including cryoapplication with scleral buckling was sufficient to reattach the retina. Although others believe it is imperative to remove the IOL when retinal detachment occurs because it hinders visualization of the peripheral retina,4 we performed surgery without removing the IOL in all three retinal detachments that were managed in our department with good anatomic and functional results. The problem of hindered vision may stem, in part, from condensation on silicone IOLs, which has been reported to interfere with the surgeon’s view of the retina during a posterior segment fluid–air exchange procedure.5,6 The use of silicone oil may also induce similar side effects.5,6
Discussion A century ago, Fukala7,8 began treating high myopia by removing the clear lens, and although the refractive results were acceptable, severe perioperative and postoperative complications were common. The beginning of the modern
era of lens implant surgery for myopia, by Barraquer,9 was also marked by frequent inflammatory and corneal complications. Today, thanks to phacoemulsification, small incision surgery, posterior chamber IOLs, and viscoelastics, CLE is being considered more and more for the treatment of both high myopia and hyperopia. Werblin10 has even asked whether CLE should be considered “routine refractive surgery.” Still, serious questions remain about the risk:benefit ratio of CLE. There is no question that intraocular surgery using current techniques increases the risk of visual loss. Perkins11 estimated the incidence of retinal detachment in the unoperated patient population with myopia greater than ⫺10 D to be 0.68% annually, or 4.76% over 7 years. In our study, the 7-year incidence of retinal detachment after CLE in eyes with preoperative myopia greater than ⫺12 D was nearly double (8.1%). In other current clinical studies with follow-up of 15 months to 7 years, the reported risk of retinal detachment after CLE in highly myopic eyes varied from 0% to 9.2%.12–16 Lee and Lee12 followed 24 eyes for 15 months after CLE for mean myopia of ⫺16.6 D (⫾1.6) and observed no retinal detachments. Similarly, Jimenez–Alfaro et al13 reported no retinal detachments 12 to 26 months after CLE in 26 eyes with mean preoperative myopia of ⫺20.8 D (⫾5.4). In their series of 31 eyes with mean myopia of ⫺12.0 D (⫾2.9) treated with CLE via phacoemulsification, Lyle and Jin14 reported no retinal detachments after a mean follow-up of 20 months. Centurion et al also reported a zero incidence of retinal detachment after 7 years in their series of 35 highly myopic eyes (mean myopia, ⫺16.5 D ⫾ 5.7) that underwent prophylactic treatment of the peripheral retina and CLE (unpublished data, 1999). In their series of 46 CLEs for high myopia (mean myopia, ⫺16.05 D ⫾ 5.01) with 15 months of follow-up, Gris et al15 reported 1 retinal detachment (2.2%) that occurred 4 weeks after surgery in an eye with a posterior capsular tear. In their retrospective evaluation of 165 eyes with axial length greater than 26 mm and/or aphakic refractive sphere of 8 D or less treated with manual extracapsular and intracapsular CLE (10 that also received argon laser prophylaxis), Barraquer et al16 found a 7.3% incidence of retinal detachment. Retinal detachment occurred an average of 30.7 months (⫾26.6 months) after surgery, with half occurring during the first 2 postoperative years. Only 15% of patients received an IOL, and the retina was reattached in 75% of cases. Barraquer et al found an association between retinal detachment and YAG capsulotomy in this series. In these studies, the risk of retinal detachment may have been related to surgical technique, degree of preoperative myopia, and duration of follow-up. Interestingly, studies with a follow-up of 4 years or less tended to have excellent results, suggesting that the risk of retinal detachment may increase with time. In our series, three of the four retinal detachments occurred between postoperative years 4 and 7. It is not clear whether argon laser prophylaxis helps reduce the incidence of retinal detachment after CLE, but it is evident that prophylactic treatment does not always prevent late retinal detachment after CLE. In our study, one eye developed retinal detachment after argon laser prophylaxis, and three eyes that
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Ophthalmology Volume 106, Number 12, December 1999 did not receive prophylactic treatment developed retinal detachment. In the review by Ripandelli et al17 of 41 retinal detachments that occurred 1 month to 4 years after CLE, 26 eyes (63.4%) underwent 360° prophylactic retinopexy on preequatorial areas. Further, some authors contend that the severity of retinal detachment may be greater when it occurs after argon laser treatment.17,18 From our study, there is no way to determine whether the prophylaxis treatment method influenced the risk of retinal detachment. However, the fact that the one eye in our study with both prophylaxis and retinal detachment had the poorest results raises the question of a possible correlation. In their review, Ripandelli et al17 reported that retinal breaks occurred along the edge of the photocoagulation in 4 of the 26 eyes that underwent retinopexy. In our study, the prophylactically treated eye that developed retinal detachment developed a tear outside the treated quadrant, although this does not preclude a correlation between the prophylaxis method and the clinical outcome. To determine whether an 8.1% risk of retinal detachment at 7 years is acceptable, we must also consider our ability to achieve other important goals of CLE in the patients with high myopia, such as good visual results and a low rate of other complications.
Visual Results Our series, using modern surgical techniques for CLE and prophylactic retinal treatment, confirms that the good refractive results obtained at 1 year remain relatively stable over the 7 years. Although UCVA did worsen most significantly in eyes with intact posterior capsules, it is important to remember that cataracts develop earlier in unoperated eyes with high myopia than in the nonmyopic unoperated population. Further, in our series, only one of the four eyes with retinal detachment developed a loss of BCVA greater than two lines. Although the risk of visual loss from intraocular surgery is greater than that from refractive corneal surgery, it is worth noting that the risk of visual loss after corneal surgery is not insignificant. Retinal detachment has been reported after laser in situ keratomileusis.19 Further, most of the visual side effects of corneal refractive surgery—variable visual acuity, starbursting effects— do not occur with CLE because the cornea remains intact.
Other Complications Both CLE and Nd:YAG capsulotomy in highly myopic eyes increase the incidence of PVD, and these vitreous changes may predispose the patient to retinal degeneration and retinal detachment. In addition, in our study, one eye developed subfoveal choroidal neovascularization, but it is unclear whether there is a potential increased risk of macular neovascular complications after CLE. The main limitation of our prospective series is size; the numbers are relatively small and the statistics are therefore fragile. Still, these data show that the primary concern about CLE in patients with high myopia remains the inevitable vitreoretinal degeneration that can ultimately lead to retinal detachment. As Goldberg20 has pointed out, CLE usually needs to be bilateral to avoid substantial aniseikonia, and this places both eyes at risk. Further follow-up of eyes
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undergoing late posterior capsulotomy is also important; opacification of the posterior capsule is not yet preventable. Long and continuous follow-up of the outcomes of CLE for high myopia is absolutely necessary before we can even consider this surgical procedure as a routine option.
References 1. Siganos DS, Pallikaris IG, Siganos CS. Clear lensectomy and intraocular lens implantation in normally sighted highly hyperopic eyes. Three-year follow-up. Eur J Implant Refract Surg 1995;7:128 –33. 2. Colin J, Robinet A. Clear lensectomy and implantation of low-power posterior chamber intraocular lens for the correction of high myopia. Ophthalmology 1994;101:107–12. 3. Colin J, Robinet A. Clear lensectomy and implantation of a low-power posterior chamber intraocular lens for correction of high myopia. A four-year follow-up. Ophthalmology 1997; 104:73– 8. 4. Batman C, Cekic O. Clear lensectomy and implantation of IOL for high myopia [letter]. Ophthalmology 1998;105:944 –5. 5. Hainsworth DP, Chen SN, Cox TA, Jaffe GJ. Condensation on polymethylmethacrylate, acrylic polymer, and silicone intraocular lenses after fluid-air exchange in rabbits. Ophthalmology 1996;103:1410 – 8. 6. Khawly JA, Lambert RJ, Jaffe GJ. Intraocular lens changes after short- and long-term exposure to intraocular silicone oil. An in vivo study. Ophthalmology 1998;105:1227–33. 7. Fukala V. Operative Behandlung der ho¨chstgradigen Myopie durch Aphakie. Albrecht von Graefes Arch Ophthalmol 1890; 36:230 – 44. 8. Fukala V. Bietrag sur hochgradigen myopie. Ber Dtsch Ophtal Ges 1896;25:265. 9. Barraquer J. La extraccion intracapsular del cristalino: Ponencia oficial del XL Congresso de la Sociedad Hispanoamericana de Grande Espana, 1962. Barcelona, Spain, Graficas Typus 1961;39. 10. Werblin TP. Should we consider clear lens extraction for routine refractive surgery? Refract Corneal Surg 1992;8:480 –1. 11. Perkins ES. Morbidity from myopia. Sight Saving Review 1979;49:11–9. 12. Lee KH, Lee JH. Long-term results of clear lens extraction for severe myopia. J Cataract Refract Surg 1996;22:1411–5. 13. Jimenez–Alfaro I, Miguelez S, Bueno JL, Puy P. Clear lens extraction and implantation of negative-power posterior chamber intraocular lenses to correct extreme myopia. J Cataract Refract Surg 1998;24:1310 – 6. 14. Lyle WA, Jin GJC. Clear lens extraction for the correction of high refractive error. J Cataract Refract Surg 1994;20:273– 6. 15. Gris O, Gu¨ell JL, Manero F, Mu¨ller A. Clear lens extraction to correct high myopia. J Cataract Refract Surg 1996;22:686 –9. 16. Barraquer C, Cavelier C, Mejia LF. Incidence of retinal detachment following clear-lens extraction in myopic patients. Arch Ophthalmol 1994;112:336 –9. 17. Ripandelli G, Billi B, Fedeli R, Stirpe M. Retinal detachment after clear lens extraction in 41 eyes with high axial myopia. Retina 1996;16:3– 6. 18. Bonnet M, Aracil P, Carneau F. Rhegmatogenous retinal detachment after prophylactic argon laser photocoagulation. Graefes Arch Clin Exp Ophthalmol 1987;225:5– 8. 19. Ozdamar A, Aras C, Sener B. Bilateral retinal detachment associated with giant retinal tear after laser-assisted in situ keratomileusis. Retina 1998;18:176 –7. 20. Goldberg MF. Clear lens extraction for axial myopia. An appraisal. Ophthalmology 1987;94:571– 82.
Colin et al 䡠 Clear Lens Extraction Discussion by Mario Stirpe, MD Clear lens extraction to correct axial myopia remains a very controversial technique because of the high risk of retinal detach1–3 ment (RD) and severe visual loss. The study by Colin and 4,5 Robinet was designed to prospectively evaluate the incidence of retinal detachment in eyes with myopia of 12 diopters or more, in which clear lens extraction (CLE) and posterior chamber intraocular lens implantation were performed to correct axial myopia. This is the third in a series of reports from these authors4,5 and shows that after several years of follow-up, a gradual increase in the incidence of vitreoretinal complications after CLE occurs over time. The clinical and historical details of the patients were not provided but are available in a previous report on this cohort.4 The value of the current study arises from the long-term follow-up after CLE. Criticisms that may arise from this study will involve the lack of discussion of (1) the possible effect of the prophylactic laser photocoagulation on the incidence of RD; (2) the effect of yttrium– aluminum– garnet (YAG)-laser capsulotomy on the incidence of RD; and (3) the importance of vitreous changes after CLE. In particular, references to points (1) and (2) are provided, but the authors do not comment on their own results. Regarding point (3), the authors reported in a previous article an incidence of preoperative posterior vitreous detachment (PVD) ranging from 40% to 71% depending on the age of the patients, but no mention is made of the preoperative condition of the vitreous in those eyes that developed RD. In a study by Ripandelli and colleagues6 on 49 eyes (of 47 patients) that underwent surgery for RD after CLE, the fellow eyes were examined. In six of these fellow eyes without RD, but which had also undergone CLE, important modifications of the vitreous were present. Conversely, no vitreous changes were detected in the 39 eyes that did not undergo CLE. Thus, Ripandelli and colleagues suggested that CLE in young subjects might play a major role in RD by precipitating vitreous changes that otherwise would have occurred more slowly over time.
From Fondazione G. B. Bietti per lo studio e la ricerca in oftalmologia, Piazza Sassari, 5, 00161 Roma, Italy. E-mail: [email protected].
We would also stress that vitreous gel in highly myopic eyes is often characterized by structural changes such as extensive vitreous liquefaction and posterior vitreous schisis.7 These changes are quite different from the more common PVD8 and should be evaluated carefully not only in relation to the lens extraction but also to prophylactic laser photocoagulation, which may induce unpredictable effects. In conclusion, although the current study was performed on a small sample, it presents important information on the long-term incidence of vitreoretinal complications after CLE. Certainly, in the future, more insight into the pathophysiology of vitreoretinal complications will be gained, as well as greater knowledge of vitreoretinal relationships and postoperative changes. References 1. Goldberg MF. Clear lens extraction for axial myopia. An appraisal. Ophthalmology 1987;94:571– 82. 2. Barraquer C, Cavalier C, Mejia LF. Incidence of retinal detachment following clear-lens extraction in myopic patients. Arch Ophthalmol 1994;112:336 –9. 3. Javitt JC. Clear-lens extraction for high myopia. Is this an idea whose time has come? Arch Ophthalmol 1994;112:321–3. 4. Colin J, Robinet A. Clear lensectomy and implantation of low-power posterior chamber intraocular lens for the correction of high myopia. Ophthalmology 1994;101:107–12. 5. Colin J, Robinet A. Clear lensectomy and implantation of a low-power posterior chamber intraocular lens for the correction of high myopia. A four-year follow-up. Ophthalmology 1997;104:73– 8. 6. Ripandelli G, Billi B, Fedeli R, Stirpe M. Retinal detachment after clear lens extraction in 41 eyes with high axial myopia. Retina 1996;16:3– 6. 7. Sebag J. The Vitreous: Structure, Function, and Pathobiology. New York: Springer–Verlag, 1989;86 –7. 8. Stirpe M, Heimann K. Vitreous changes and retinal detachment in highly myopic eyes. Eur J Ophthalmol 1996;6: 50 – 8.
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