Accepted Manuscript Refractive Changes after Lens-Sparing Vitrectomy for Rhegmatogenous Retinal Detachment Yoshifumi Okamoto , Fumiki Okamoto , Takahiro Hiraoka , Tetsuro Oshika PII:
S0002-9394(14)00289-X
DOI:
10.1016/j.ajo.2014.05.018
Reference:
AJOPHT 8924
To appear in:
American Journal of Ophthalmology
Received Date: 3 February 2014 Revised Date:
15 May 2014
Accepted Date: 16 May 2014
Please cite this article as: Okamoto Y, Okamoto F, Hiraoka T, Oshika T, Refractive Changes after LensSparing Vitrectomy for Rhegmatogenous Retinal Detachment, American Journal of Ophthalmology (2014), doi: 10.1016/j.ajo.2014.05.018. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Refractive Changes after Lens-Sparing Vitrectomy for Rhegmatogenous Retinal Detachment
Yoshifumi Okamoto, Fumiki Okamoto, Takahiro Hiraoka, and Tetsuro Oshika
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Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan Short title: Refractive Changes after Vitrectomy for Retinal Detachment
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Corresponding Author: Yoshifumi Okamoto, Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8575, Japan. Tel: +81-29-853-3148, Fax: +81-29-853-3148, E-mail: [email protected]
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ABSTRACT Purpose: To evaluate refractive changes after lens-sparing vitrectomy for rhegmatogenous retinal detachment (RD). Design: Retrospective case series. Methods: A retrospective chart review was conducted in 66 eyes of 66 patients (50.0 ± 9.9 years old) who had undergone lens-sparing vitrectomy for rhegmatogenous RD. Spherical equivalent refractive power was evaluated before and 1, 2, 3, 6, 9, 12, and 15 months after vitrectomy. The relation between refractive changes and several parameters was investigated, such as axial length, presence of preoperative hemorrhage, preoperative spherical equivalent, retinal tear size, logMAR best corrected visual acuity, number of laser photocoagulation, occurrence of postoperative vitreous hemorrhage, and degree of postoperative inflammatory reaction. Surgical parameters examined included operative time, wide-angle viewing system use, intraoperative adjuvant and gas tamponade use, vitrectomy system gauge, and surgeon. Results: Significant and continuous myopic shift was observed after vitrectomy throughout the study period. Spherical equivalent was not significantly different between the operated eyes and the fellow control eyes until 3 months after vitrectomy, but the operated eyes were significantly more myopic at 3 months and later postoperatively (P < 0.05). Of the 58 eyes finally included (8 patients lost to follow-up), 27 (47%) underwent cataract surgery after vitrectomy. Patients who underwent cataract surgery were significantly older than those who did not (P < 0.05); no other examined parameter was significantly different between groups. Conclusions: A significant myopic progression occurred in eyes after lens-sparing vitrectomy for rhegmatogenous RD. A considerable amount of anisometropia occurred, even in the early postoperative period. Patient age was the only risk factor with the potential to progress the nuclear sclerotic cataract progression after vitrectomy.
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INTRODUCTION Since the development of pars plana vitrectomy using a 17-gauge vitreous cutter in 1970,1 the surgical techniques employed in vitrectomy have dramatically improved, especially with the recent introduction of transconjunctival, small-gauge, sutureless vitrectomy.2-5 Smaller incisions and shorter operation times have reduced the degree of operative invasion, and led to faster postoperative recovery.4,6 In 1975, Michels and Ryan7 provided the first report on the occurrence of progressive nuclear sclerosis after vitrectomy in patients with proliferative diabetic retinopathy. Since then, acceleration of nuclear sclerotic cataract and subsequent vision loss have been well recognized as potential adverse surgical outcomes of lens-sparing vitrectomy.8-14 Nuclear sclerotic cataracts also frequently affect refraction of the eye, shifting it towards myopic in the majority of cases.15 To date, most quantitative evaluations of nuclear sclerotic cataracts have been done by evaluating lens opacity with Scheimpflug photography and fluorophotometry.16,17 Wong and associates16 reported the progression of lens opacity and scattering in patients with macular hole using Scheimpflug photography. Ogura and associates17 used fluorophotometry and found that lens autofluorescence in vitrectomized eyes was significantly higher than in the contralateral control eyes. To the best of our knowledge, there is only one report of myopic shift after pars plana vitrectomy.18 However, that study did not involve longitudinal evaluation. The purpose of this study was to evaluate the time-course of refractive changes after lens-sparing vitrectomy for rhegmatogenous retinal detachment (RD).
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METHODS This retrospective study included 64 vitrectomized eyes of 64 patients (50 male and 14 female) averaging 50.0 ± 9.9 years (mean ± standard deviation) of age (range: 13–65 years). All subjects had undergone lens-sparing vitrectomy for rhegmatogenous RD at Tsukuba University Hospital between July 1, 2008 and April 30, 2013. To be included in the study, patients had to have a primary rhegmatogenous RD and be phakic. None of the patients had a visually significant cataract at the time of surgery. Patients were excluded from analyses if they had a history of ocular surgery, or if ocular disease was present that could affect refraction and/or visual function. This study was approved retrospectively by the Institutional Review Board at the Tsukuba University Hospital, and study conduct adhered to the tenets of the Declaration of Helsinki. All surgeries were performed under local trans-Tenon’s retrobulbar anesthesia by one of two surgeons (FO, YO). One surgeon (FO) operated on 47 eyes using a 23-gauge vitrectomy system, and the other (YO) operated on 19 eyes using a 25-gauge vitrectomy system. All surgical procedures were performed using the Accurus microincision vitrectomy system (Alcon Laboratories, Fort Worth, TX, USA). Contact lenses (Truncated contact lens, HOYA Corp, Tokyo, Japan) and a wide-angle viewing system (Resight, Carl Zeiss Meditec AG, Jena, Germany) were used to facilitate posterior visualization during surgery.19 The total gas-fluid exchange were used air or 20% sulfur hexafluoride (SF6). In order to secure vitreous traction release around the
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breaks and prevent vitreous incarceration of the sclerotomy wound, triamcinolone acetonide was used as needed. All patients were kept in the prone position for a few days after surgery. Preoperative and postoperative refractive errors were measured in all eyes using an automatic refractometer (RK-2, Canon Inc., Tokyo, Japan). Axial length was evaluated using noncontact optical biometry (IOLMaster, Carl Zeiss Meditec AG, Jena, Germany) before primary vitrectomy. Each clinical parameter was evaluated at baseline (before surgery) and 1, 2, 3, 6, 9, 12, and 15 months after lens-sparing vitrectomy. Data were analyzed using repeated-measures analysis of variance (ANOVA) to assess the time-course of changes. If significant differences were observed, a Dunnett’s test was performed. Data obtained from the operative and contralateral eyes were also compared, and differences were tested for statistical significance using Student’s t test. A single linear regression was used to calculate regression coefficients of refractive power, which was chosen as an outcome variable. Risk factors for cataract progression were assessed by comparing patient demographic characteristics and intra- and postoperative parameters in patients who underwent cataract surgery in the follow-up period and those who did not. Statistical significance was tested using Student’s t test or the chi-squared test, as appropriate. Correlations between refractive power progression rates after lens-sparing vitrectomy and patient age, axial length, preoperative refractive power, circumferential retinal tear dimension, operation time, and the photocoagulation number were analyzed by Spearman’s rank correlation. Refractive progression rate was defined as the mean refractive change per month between the baseline and final visits. When refractive power could not be measured before lens-sparing vitrectomy because of macular detachment or vitreous hemorrhage, the refraction obtained at the first post-vitrectomy visit was defined as the baseline refraction. Statistical significance was defined as P < 0.05. All statistical analyses were performed with StatView statistical software (version 5.0, SAS Institute, Cary, NC).
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RESULTS Patient clinical characteristics, intraoperative parameters, and postoperative complications are summarized in Table 1. No patient had a rhegmatogenous RD secondary to a globe contusion, or had proliferative vitreoretinopathy. The retina was successfully reattached with the initial operation in all eyes, and no serious intraoperative or postoperative complications (e.g., subretinal hemorrhage, elevated intraocular pressure for >7 days, choroidal detachment) were observed. A gas-fluid exchange was performed in 64 of 66 patients and the gas (air or 20% SF6) was selected according to ocular status. Two patients did not receive gas-fluid exchange due to the limited area of their retinal detachment. After lens-sparing vitrectomy, patients were followed up for an average of 11.6 ± 11.8 months. Following vitrectomy, 6 of 64 patients did not return to our clinic and were lost to follow-up. Of the remaining 58 eyes, 27 (46.6%) underwent cataract surgery during the study period. Cataract type was nuclear sclerosis in every case, and there was no case of cortical or posterior
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subcapsular cataract. All cataract surgeries were successful and uneventful. Neither intraoperative (e.g., lens capsule rupture) nor postoperative (e.g., zonule formation, persistent ocular hypertension) complications were observed during the follow-up period. Table 2 demonstrates the time-course of refractive changes after lens-sparing vitrectomy for rhegmatogenous RD. The operative eyes showed a progressive myopic shift (Figure 1), and the refractions 6 months and later after vitrectomy were significantly different from baseline (P < 0.05, Dunnett’s test). The refractions in the contralateral eyes were stable throughout the study period (Figure 1). There was no significant difference in postoperative spherical equivalent between the operative and contralateral eyes until 3 months after surgery, but the operative eyes were more myopic than the contralateral eyes 3 months or later after lens-sparing vitrectomy (all P < 0.05, Student’s t test). A significant negative correlation was found between time after vitrectomy and spherical equivalent in the operative eyes (R2 = 0.216, P < 0.001), but not in the contralateral eyes (R2 = 0.016, P = 0.78). When comparison of baseline clinical characteristics was performed between patients who underwent cataract surgery in the follow-up period (27 eyes, 46.6%) and patients who did not (31 eyes, 53.4%), patients who underwent cataract surgery were significantly older than patients who did not (50.9 ± 15.1 and 49.7 ± 18.9 respectively, P < 0.001). Differences between these groups relating to sex, ocular side, axial length, preoperative spherical equivalent, and circumferential dimension of retinal tears were not significant (P = 0.52, 0.44, 0.41, 0.45, and 0.26 respectively). Furthermore, when comparisons of intraoperative parameters including operative time, gauge of vitrectomy system, use of wide-angle viewing system, laser photocoagulation number, use of gas tamponade, and best corrected visual acuity were performed between these two groups, significant differences were not observed for any of them (P = 0.79, 0.08, 0.11, 0.16, 0.58, and 0.19 respectively). The progression rate of the refractive spherical equivalent following vitrectomy was significantly correlated with patient age (P < 0.01; Figure 2). However, no significant relationships were found between the spherical equivalent progression rate and axial length (P = 0.14), preoperative spherical equivalent (P = 0.69), retinal tear circumference (P = 0.53), operation time (P = 0.37), or the number of photocoagulation spots (P = 0.61). DISCUSSION Nuclear sclerosis of the crystalline lens is a common complication of lens-sparing vitrectomy, leading to increased lens opacity and myopic shift.15 Various articles have reported nuclear sclerotic changes in vitrectomized eyes with posterior segment diseases.8-14,16,17 The main outcome measure of almost all previous reports was the degree of lens opacity. Although there is one report of refractive change in patients undergoing vitrectomy that progressed to myopia at 3 or 4 months, temporal changes were not observed.18 To the best of our knowledge, the present study is the first to report detailed refractive changes over time, and anisometropia, after lens-sparing vitrectomy. Myopic shifts were first observed 1 month after surgery in the operative
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eyes, and tended to gradually increase each month during the study period. Significant refractive changes in the contralateral eyes were not observed, suggesting that lens-sparing vitrectomy substantially affects lens status from early in the postoperative period. Compared with a previous report, more major myopic shift was seen with -4.03 diopters (D) at 12 months after surgery (-4.97 D at 15 months) in the present study.18 All patients in the present study needed correction of the refractive error by glasses or contact lenses to obtain best corrected visual acuity after surgery. Due to the major refractive changes in this short period after surgery, patients require frequent exchange of their glasses or contact lenses, and it is hard to obtain a stable best corrected visual acuity. Consequently, the longitudinal refractive changes reduce the quality of vision in daily life, even in cases with good visual acuity after surgery. Additionally, similar results were observed with regard to the time-course of anisometropic refractive changes. The difference in refractive power between the operative eye and the contralateral eye was statistically significant at 3 months and later after vitrectomy, and >3 D of anisometropia was observed at 6 months after surgery, which was more pronounced at 15 months after surgery. Brooks and associates21 reported that binocular visual function also deteriorates proportionally with the degree of anisometropia, even when only a 1-D anisometropia exists. However, it remains unclear what level of anisometropia requires correction in healthy adults. The above-mentioned reports suggest that patients who have undergone lens-sparing vitrectomy may develop binocular and stereoscopic vision deficits from anisometropia, even if they have good visual acuity in both eyes.19-21 In order to achieve the optimal quality of vision after vitrectomy, both best-corrected visual acuity and interocular refractive differences (i.e., anisometropia) in the early postoperative period should be considered while assessing changes over time. In the present study, cataract surgery was performed in 27 of 58 eyes (46.6%) during the study follow-up period. In a previous study,11 cataract surgery was also performed in 47% of vitrectomized patients during the initial 15 months after surgery. Various analyses have been performed to determine which factors are correlated with cataract progression after lens-sparing vitrectomy, but the significant associated factors remain unclear to date. It has been reported that several factors are associated with cataract progression after lens-sparing vitrectomy, and some reports have suggested that patient age is the most important factor.14,22 Melberg and Thomas22 showed that the 2-year incidence of post-vitrectomy nuclear sclerosis for patients younger than 50 years of age was 7%, significantly lower than the 79% incidence in patients older than 50 years of age. Thompson14 reported that the nuclear sclerosis scores of vitrectomized eyes of patients younger than 50 years showed minimal increases, whereas eyes of patients older than 50 years showed similar increases related to nuclear sclerosis. The present study examined various factors potentially associated with cataract progression, including patients’ clinical characteristics, intraoperative parameters, and postoperative complications, and the only parameter significantly associated with cataract progression was patient age, as has been previously reported.14,22,23 Previous reports have investigated intraoperative parameters including the gauge of the vitrectomy system,
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operation time, and the use of gas tamponade.14,24,25 However, none of these intraoperative parameters were significantly associated with cataract progression. Age is one of the important factors of cataract progression.26 In the present study, myopia following lens-sparing vitrectomy significantly progressed with age. This suggests that age remains a significant risk factor for cataract progression, even after lens-sparing vitrectomy. In the present study, almost all patients aged older than 50 years exhibited a myopic shift (Figure 2). The result that an age of approximately 50 years represented a threshold for cataract progression in vitrectomized eyes was concordant with the results of previous studies.14,22 Whereas, in age-related nuclear cataract, the increase in prevalence of lens opacities is gradual, particularly until the age of 60 years, and resembles an exponential curve with a relatively sharp increase in prevalence at the age of approximately 60 years.26 The difference in threshold age of nuclear cataract progression between age-related cataract and vitrectomy induced cataract is significant; however, it is currently not known whether the mechanism of cataract progression after lens-sparing vitrectomy is the same as that of the progression of age-related nuclear cataract. If cataract progression after lens-sparing vitrectomy has pathogenic mechanisms similar to those of age-related nuclear cataract, in considering the pathogenic mechanism of cataract progression, three possible mechanisms have been proposed: intraoperative light toxicity, intraoperative lens protein oxidation, and surgically-induced alteration of the lens’ biochemical microenvironment. Holekamp and associates27 proposed the hypothesis that increased exposure to oxygen is responsible for nuclear cataract progression as well as age-related cataract progression, and the vitreous oxygen tension in patients with ischemic diabetic retinopathy was significantly lower in their study, which may be responsible for the lower prevalence of nuclear sclerotic cataract. They also reported that partial oxygen pressure was significantly higher after vitrectomy, which resulted in oxidative damage to the crystalline lens.28 In addition, they noted the role of vitreous ascorbate, which consumes oxygen and plays an important role in maintaining the low oxygen environment of the normal vitreous cavity.27 In fact, the ascorbate concentration in human vitreous is more than 30 times that in blood.29 Vitrectomy replaces the vitreous with saline, simultaneously decreasing levels of ascorbate and increasing levels of oxygen, which may accelerate nuclear sclerotic cataract progression. If the liquefaction and removal of the vitreous is related to nuclear sclerosis progression, nonvitrectomizing vitrectomy, which leaves as much vitreous as possible, might be effective for preventing cataract progression.30 Nonvitrectomizing vitrectomy is useful in patients with epiretinal membrane. It may also be that vitrectomy for rhegmatogenous RD, which requires the complete removal of the vitreous, might accelerate nuclear sclerotic cataract progression more than vitrectomy for epiretinal membrane. Further study is needed to determine the relationship between remaining vitreous humor and vitreous cavity oxygen levels, and how this relates to cataract formation. Treatment for rhegmatogenous RD commonly involves not only vitrectomy but also scleral buckling. There are no significant differences in
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anatomical success rate between the two surgical procedures, whereas in a multicenter clinical study, cataract progression rate was significantly lower in the scleral buckling group.31 This result suggests that refractive change due to nuclear sclerotic cataract may be limited in patients with rhegmatogenous RD who undergo scleral buckling. In patients aged older than 50 years who underwent lens-sparing vitrectomy, weaknesses including reduced accommodative power, increased crystalline lens aberrations, and rapid nuclear sclerotic myopia progression have been reported.21,22,32,33 These reports may lead to a conclusion that lens-sparing vitrectomy causes the loss of crystalline lens function early in the postoperative period. It is reasonable to surmise that scleral buckling is the preferable method in terms of preservation of crystalline lens function, except in cases such as media opacity, and multiple or undetermined breaks. However, there have been no reports of long-term refractive changes after scleral buckling for rhegmatogenous RD, and further studies are required to evaluate its effects on nuclear sclerotic progression of crystalline lens. A limitation of this study is that refractive power after vitrectomy is influenced by multiple factors. Vitrectomy causes changes in the crystalline lens, corneal topography, and axial length, all of which influence total ocular refractive values.34,35 Furthermore, all refractions in the current study were performed prior to mydriasis. Although the effects of accommodation should have been minimal in our mostly older study population, future studies with mydriatic refractions should be performed to obtain more precise data.21,32 Another potential study limitation is that cataract surgery was performed on the basis of a patient’s subjective decision, and not on predefined clinical criteria. Therefore, some patients with substantial visual loss or anisometropia, in whom cataract surgery was indicated, did not undergo the procedure. A prospective study with objective assessments of crystalline lens changes and objective criteria for cataract surgery would have been preferable. In conclusion, refractive changes after lens-sparing vitrectomy for rhegmatogenous RD consistently progressed during the study period. Because postoperative anisometropia occurred 3 months after surgery, it is likely that it degrades binocular visual function early in the postoperative period. The only risk factor associated with cataract progression after lens-sparing vitrectomy was patient age.
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ACCEPTED MANUSCRIPT Acknowledgements/Disclosures
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a. Funding/Support: No author has received public or private funding support for this research. b. Financial Disclosures: No author has any relevant financial disclosures to declare. c. Author Contributions: Design of the study (Y.O, F.O., T.H., T.O.); conduct of the study (Y.O., F.O., T.H.); data collection (Y.O.); management, analysis, and interpretation of the data (Y.O., F.O.); preparation of the manuscript (Y.O.); review of the manuscript (T.O.); approval of the manuscript (Y.O., F.O., T.H., T.O.). d. Other Acknowledgments: None.
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References 1. Machemer R, Parel JM, Buettner H. A new concept for vitreous surgery. 1. Instrumentation. Am J Ophthalmol 1972;73(1):1-7. 2. O'Malley C, Heintz RM Sr. Vitrectomy with an alternative instrument system. Ann Ophthalmol 1975;7(4):585-588,591-594. 3. de Juan E Jr, Hickingbotham D. Refinements in microinstrumentation for vitreous surgery. Am J Ophthalmol 1990;109(2):218-220. 4. Fujii GY, de Juan E Jr, Humayun MS, et al. A new 25-gauge instrument system for transconjunctival sutureless vitrectomy surgery. Ophthalmology 2002;109(10):1807-1812. 5. Eckardt C. Transconjunctival sutureless 23-gauge vitrectomy. Retina 2005;25(2):208-211. 6. Lakhanpal RR, Humayun MS, de Juan E Jr, et al. Outcomes of 140 consecutive cases of 25-gauge transconjunctival surgery for posterior segment disease. Ophthalmology 2005;112(5):817-824. 7. Michels RG, Ryan SJ Jr. Results and complications of 100 consecutive cases of pars plana vitrectomy. Am J Ophthalmol 1975;80(1):24-29. 8. Cherfan GM, Michels RG, de Bustros S, Enger C, Glaser BM. Nuclear sclerotic cataract after vitrectomy for idiopathic epiretinal membranes causing macular pucker. Am J Ophthalmol 1991;111(4):434-438. 9. Thompson JT, Glaser BM, Sjaarda RN, Murphy RP. Progression of nuclear sclerosis and long-term visual results of vitrectomy with transforming growth factor beta-2 for macular holes. Am J Ophthalmol 1995:119(1);48-54. 10. Schachat AP, Oyakawa RT, Michels RG, Rice TA. Complications of vitreous surgery for diabetic retinopathy. II. Postoperative complications. Ophthalmology 1983;90(5):522-530. 11. de Bustros S, Thompson JT, Michels RG, Enger C, Rice TA, Glaser BM. Nuclear sclerosis after vitrectomy for idiopathic epiretinal membranes. Am J Ophthalmol 1988;105(2):160-164. 12. Michels RG. Vitrectomy for macular pucker. Ophthalmology 1984;91(11):1384-1388. 13. Freeman WR, Azen SP, Kim JW, el-Haig W, Mishell DR 3rd, Bailey I. Vitrectomy for the treatment of full-thickness stage 3 or 4 macular holes. Results of a multicentered randomized clinical trial. Arch Ophthalmol 1997;115(1):11-21. 14. Thompson JT. The role of patient age and intraocular gas use in cataract progression after vitrectomy for macular holes and epiretinal membranes. Am J Ophthalmol 2004;137(2):250-257. 15. Kawakubo H, Sato Y, Shimada H, et al. Myopic change in refraction due to nuclear sclerotic changes after vitreous surgery (comparison of epimacular membrane and macular hole). Folia Ophthalmol Jpn 1996;47(4):396-400. 16. Wong SC, Clare G, Bunce C, Sullivan PM, Gregor ZJ, Ezra E. Cataract progression in macular hole cases: results with vitrectomy or with observation. J Cataract Refract Surg. 2012;38(7):1176-1180. 17. Ogura Y, Takanashi T, Ishigooka H, Ogino N. Quantitative analysis of lens changes after vitrectomy by fluorophotometry. Am J Ophthalmol 1991;111(2):179-183.
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18. Tseng PC, Woung LC, Tseng GL, et al. Refractive change after pars plana vitrectomy. Taiwan J Ophthalmol 2012;2(1):18-21. 19. Okamoto F, Nakano S, Oshika T. Truncated contact lenses for peripheral vitrectomy. Retina 2012;32(8):1682-1684. 20. Brooks SE, Johnson D, Fischer N. Anisometropia and binocularity. Ophthalmology 1996;103(7):1139-1143. 21. Richdale K, Sinnott LT, Bullimore MA, et al. Quantification of age-related and per diopter accommodative changes of the lens and ciliary muscle in the emmetropic human eye. Invest Ophthalmol Vis Sci 2013;54(2):1095-1105. 22. Melberg NS, Thomas MA. Nuclear sclerotic cataract after vitrectomy in patients younger than 50 years of age. Ophthalmology 1995;102(10):1466-1471. 23. Smiddy WE, Feuer W. Incidence of cataract extraction after diabetic vitrectomy. Retina 2004;24(4):574-581. 24. Cheng L, Azen SP, El-Bradey MH, et al. Duration of vitrectomy and postoperative cataract in the vitrectomy for macular hole study. Am J Ophthalmol 2001;132(6):881-887. 25. Almony A, Holekamp NM, Bai F, Shui YB, Beebe D. Small-gauge vitrectomy does not protect against nuclear sclerotic cataract. Retina 2012;32(3):499-505. 26. Richter GM, Torres M, Choudhury F, Azen SP, Varma, R. Risk factors for cortical, nuclear, posterior subcapsular, and mixed lens opacities: the Los Angeles Latino Eye Study. Ophthalmology 2012;119(3):547-554. 27. Holekamp NM, Bai F, Shui YB, Almony A, Beebe DC. Ischemic diabetic retinopathy may protect against nuclear sclerotic cataract. Am J Ophthalmol 2010;150(4):543-550. 28. Holekamp NM, Shui YB, Beebe DC. Vitrectomy surgery increases oxygen exposure to the lens: a possible mechanism for nuclear cataract formation. Am J Ophthalmol 2005;139(2):302-310. 29. Shui YB, Holekamp NM, Kramer BC, et al. The gel state of the vitreous and ascorbate-dependent oxygen consumption: relationship to the etiology of nuclear cataracts. Arch Ophthalmol 2009;127(4):475-482. 30. Sawa M, Ohji M, Kusaka S, et al. Nonvitrectomizing vitreous surgery for epiretinal membrane long-term follow-up. Ophthalmology 2005;112(8):1402-1408. 31. Heimann H, Bartz-Schmidt KU, Bornfeld N, Weiss C, Hilgers RD, Foerster MH. Scleral buckling versus primary vitrectomy in rhegmatogenous retinal detachment: a prospective randomized multicenter clinical study. Ophthalmology 2007;114(12):2142-2154.
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32. Anderson HA, Hentz G, Glasser A, Stuebing KK, Manny RE. Minus-lens-stimulated accommodative amplitude decreases sigmoidally with age: a study of objectively measured accommodative amplitudes from age 3. Invest Ophthalmol Vis Sci 2008;49(7):2919-2926. 33. Fujikado T, Kuroda T, Ninomiya S, et al. Age-related changes in ocular and corneal aberrations. Am J Ophthalmol 2004;138(1):143-146. 34. Okamoto F, Okamoto C, Sakata N, et al. Changes in corneal topography after 25-gauge transconjunctival sutureless vitrectomy versus after 20-gauge standard vitrectomy. Ophthalmology 2007;114(12):2138-2141. 35. Brazitikos PD, Androudi S, Christen WG, Stangos NT. Primary pars plana vitrectomy versus scleral buckle surgery for the treatment of pseudophakic retinal detachment: a randomized clinical trial. Retina 2005;25(8):957-964.
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Figure 1. Changes in spherical equivalent over time in eyes after lens-sparing vitrectomy for rhegmatogenous retinal detachment. A significant negative correlation was found between time after vitrectomy and spherical equivalent (R2 = 0.216, P < 0.001). However, there was no correlation between time after vitrectomy and refraction in contralateral eyes (R2 = 0.016, P = 0.78). Values are presented as mean ± SE.
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Figure 2 Relationship between age and myopic progression rate after lens-sparing vitrectomy for rhegmatogenous retinal detachment. There was a significant correlation between the progression rate and patient age (P < 0.01).
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50.0 ± 9.9 50/14
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Sex (male/female) Ocular side (left/right)
25/39
Preoperative vitreous hemorrhage (yes/no)
12/52
Axial length (mm) (24 eyes)
26.0 ± 1.9
-5.68 ± 3.71
Circumferential dimension of retinal tears (degrees)
62.3 ± 33.5
Operation time (minutes)
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Macular status (on/off)
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Preoperative spherical equivalent (diopter) (38 eyes)
27/37 51.3 ± 17.4 47/17
Use of wide-angle viewing system (yes/no)
9/55
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Gauge of vitrectomy system (23-gauge/25-gauge)
Laser photocoagulation number (shots) Use of gas tamponade (none/air/20% SF6)
783 ± 454 2/13/49 21/42
Occurrence of vitreous hemorrhage (yes/no)
2/62
Occurrence of fibrin reaction (yes/no)
2/62
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Use of triamcinolone acetonide for vitreous visualization (yes/no)
0.23 ± 0.33 (20/34) Values presented as mean ± standard deviation. BCVA = best corrected visual acuity, logMAR = logarithm of minimum angle of resolution BCVA following vitrectomy (logMAR) (Snellen equivalent)
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Table 2. Time-course of refractive changes after lens-sparing vitrectomy for rhegmatogenous retinal detachment Average deviation from baseline (diopter)
Contralateral eyes (diopter)
Degree of Anisometropia (diopter)
P value
0.36
0.49
1.02
0.18
1.15
0.44
-5.65 ± 3.26
2.02
0.05†
-5.42 ± 3.44
3.12
0.005†
-6.00 ± 2.82
3.43
0.04†
-6.25 ± 2.68
3.56
0.05†
-5.51 ± 2.79
5.24
0.03†
-5.78 ± 3.69
-6.14 ± 3.44
1 month
-6.89 ± 4.17
-1.11
-5.87 ± 3.42
2 months
-7.44 ± 2.92
-1.66
-6.29 ± 2.38
3 months
-7.67 ± 4.40
-1.89
6 months
-8.54 ± 4.21*
-2.76
9 months
-9.43 ± 4.17*
-3.65
12 months
-9.81 ± 4.58*
-4.03
15 months
-10.75 ± 4.65*
-4.97
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Baseline
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Operated eyes (diopter)
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Values are presented as mean ± standard deviation. *Statistical difference from baseline (Dunnett’s test). †Statistical difference between operative and contralateral eyes (Student’s t test).
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Yoshifumi Okamoto graduated from Tsukuba University School of Medicine, Ibaraki, Japan in 2000. He completed his ophthalmology residency at University of Tsukuba Hospital. Dr Okamoto is currently the assistant professor in University of Tsukuba, Department of Ophthalmology. He specializes in vitreoretinal surgery and age-related
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macular degeneration.
S0002-9394(14)00289-X
DOI:
10.1016/j.ajo.2014.05.018
Reference:
AJOPHT 8924
To appear in:
American Journal of Ophthalmology
Received Date: 3 February 2014 Revised Date:
15 May 2014
Accepted Date: 16 May 2014
Please cite this article as: Okamoto Y, Okamoto F, Hiraoka T, Oshika T, Refractive Changes after LensSparing Vitrectomy for Rhegmatogenous Retinal Detachment, American Journal of Ophthalmology (2014), doi: 10.1016/j.ajo.2014.05.018. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
ACCEPTED MANUSCRIPT Refractive Changes after Lens-Sparing Vitrectomy for Rhegmatogenous Retinal Detachment
Yoshifumi Okamoto, Fumiki Okamoto, Takahiro Hiraoka, and Tetsuro Oshika
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Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan Short title: Refractive Changes after Vitrectomy for Retinal Detachment
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Corresponding Author: Yoshifumi Okamoto, Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8575, Japan. Tel: +81-29-853-3148, Fax: +81-29-853-3148, E-mail: [email protected]
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ABSTRACT Purpose: To evaluate refractive changes after lens-sparing vitrectomy for rhegmatogenous retinal detachment (RD). Design: Retrospective case series. Methods: A retrospective chart review was conducted in 66 eyes of 66 patients (50.0 ± 9.9 years old) who had undergone lens-sparing vitrectomy for rhegmatogenous RD. Spherical equivalent refractive power was evaluated before and 1, 2, 3, 6, 9, 12, and 15 months after vitrectomy. The relation between refractive changes and several parameters was investigated, such as axial length, presence of preoperative hemorrhage, preoperative spherical equivalent, retinal tear size, logMAR best corrected visual acuity, number of laser photocoagulation, occurrence of postoperative vitreous hemorrhage, and degree of postoperative inflammatory reaction. Surgical parameters examined included operative time, wide-angle viewing system use, intraoperative adjuvant and gas tamponade use, vitrectomy system gauge, and surgeon. Results: Significant and continuous myopic shift was observed after vitrectomy throughout the study period. Spherical equivalent was not significantly different between the operated eyes and the fellow control eyes until 3 months after vitrectomy, but the operated eyes were significantly more myopic at 3 months and later postoperatively (P < 0.05). Of the 58 eyes finally included (8 patients lost to follow-up), 27 (47%) underwent cataract surgery after vitrectomy. Patients who underwent cataract surgery were significantly older than those who did not (P < 0.05); no other examined parameter was significantly different between groups. Conclusions: A significant myopic progression occurred in eyes after lens-sparing vitrectomy for rhegmatogenous RD. A considerable amount of anisometropia occurred, even in the early postoperative period. Patient age was the only risk factor with the potential to progress the nuclear sclerotic cataract progression after vitrectomy.
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INTRODUCTION Since the development of pars plana vitrectomy using a 17-gauge vitreous cutter in 1970,1 the surgical techniques employed in vitrectomy have dramatically improved, especially with the recent introduction of transconjunctival, small-gauge, sutureless vitrectomy.2-5 Smaller incisions and shorter operation times have reduced the degree of operative invasion, and led to faster postoperative recovery.4,6 In 1975, Michels and Ryan7 provided the first report on the occurrence of progressive nuclear sclerosis after vitrectomy in patients with proliferative diabetic retinopathy. Since then, acceleration of nuclear sclerotic cataract and subsequent vision loss have been well recognized as potential adverse surgical outcomes of lens-sparing vitrectomy.8-14 Nuclear sclerotic cataracts also frequently affect refraction of the eye, shifting it towards myopic in the majority of cases.15 To date, most quantitative evaluations of nuclear sclerotic cataracts have been done by evaluating lens opacity with Scheimpflug photography and fluorophotometry.16,17 Wong and associates16 reported the progression of lens opacity and scattering in patients with macular hole using Scheimpflug photography. Ogura and associates17 used fluorophotometry and found that lens autofluorescence in vitrectomized eyes was significantly higher than in the contralateral control eyes. To the best of our knowledge, there is only one report of myopic shift after pars plana vitrectomy.18 However, that study did not involve longitudinal evaluation. The purpose of this study was to evaluate the time-course of refractive changes after lens-sparing vitrectomy for rhegmatogenous retinal detachment (RD).
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METHODS This retrospective study included 64 vitrectomized eyes of 64 patients (50 male and 14 female) averaging 50.0 ± 9.9 years (mean ± standard deviation) of age (range: 13–65 years). All subjects had undergone lens-sparing vitrectomy for rhegmatogenous RD at Tsukuba University Hospital between July 1, 2008 and April 30, 2013. To be included in the study, patients had to have a primary rhegmatogenous RD and be phakic. None of the patients had a visually significant cataract at the time of surgery. Patients were excluded from analyses if they had a history of ocular surgery, or if ocular disease was present that could affect refraction and/or visual function. This study was approved retrospectively by the Institutional Review Board at the Tsukuba University Hospital, and study conduct adhered to the tenets of the Declaration of Helsinki. All surgeries were performed under local trans-Tenon’s retrobulbar anesthesia by one of two surgeons (FO, YO). One surgeon (FO) operated on 47 eyes using a 23-gauge vitrectomy system, and the other (YO) operated on 19 eyes using a 25-gauge vitrectomy system. All surgical procedures were performed using the Accurus microincision vitrectomy system (Alcon Laboratories, Fort Worth, TX, USA). Contact lenses (Truncated contact lens, HOYA Corp, Tokyo, Japan) and a wide-angle viewing system (Resight, Carl Zeiss Meditec AG, Jena, Germany) were used to facilitate posterior visualization during surgery.19 The total gas-fluid exchange were used air or 20% sulfur hexafluoride (SF6). In order to secure vitreous traction release around the
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breaks and prevent vitreous incarceration of the sclerotomy wound, triamcinolone acetonide was used as needed. All patients were kept in the prone position for a few days after surgery. Preoperative and postoperative refractive errors were measured in all eyes using an automatic refractometer (RK-2, Canon Inc., Tokyo, Japan). Axial length was evaluated using noncontact optical biometry (IOLMaster, Carl Zeiss Meditec AG, Jena, Germany) before primary vitrectomy. Each clinical parameter was evaluated at baseline (before surgery) and 1, 2, 3, 6, 9, 12, and 15 months after lens-sparing vitrectomy. Data were analyzed using repeated-measures analysis of variance (ANOVA) to assess the time-course of changes. If significant differences were observed, a Dunnett’s test was performed. Data obtained from the operative and contralateral eyes were also compared, and differences were tested for statistical significance using Student’s t test. A single linear regression was used to calculate regression coefficients of refractive power, which was chosen as an outcome variable. Risk factors for cataract progression were assessed by comparing patient demographic characteristics and intra- and postoperative parameters in patients who underwent cataract surgery in the follow-up period and those who did not. Statistical significance was tested using Student’s t test or the chi-squared test, as appropriate. Correlations between refractive power progression rates after lens-sparing vitrectomy and patient age, axial length, preoperative refractive power, circumferential retinal tear dimension, operation time, and the photocoagulation number were analyzed by Spearman’s rank correlation. Refractive progression rate was defined as the mean refractive change per month between the baseline and final visits. When refractive power could not be measured before lens-sparing vitrectomy because of macular detachment or vitreous hemorrhage, the refraction obtained at the first post-vitrectomy visit was defined as the baseline refraction. Statistical significance was defined as P < 0.05. All statistical analyses were performed with StatView statistical software (version 5.0, SAS Institute, Cary, NC).
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RESULTS Patient clinical characteristics, intraoperative parameters, and postoperative complications are summarized in Table 1. No patient had a rhegmatogenous RD secondary to a globe contusion, or had proliferative vitreoretinopathy. The retina was successfully reattached with the initial operation in all eyes, and no serious intraoperative or postoperative complications (e.g., subretinal hemorrhage, elevated intraocular pressure for >7 days, choroidal detachment) were observed. A gas-fluid exchange was performed in 64 of 66 patients and the gas (air or 20% SF6) was selected according to ocular status. Two patients did not receive gas-fluid exchange due to the limited area of their retinal detachment. After lens-sparing vitrectomy, patients were followed up for an average of 11.6 ± 11.8 months. Following vitrectomy, 6 of 64 patients did not return to our clinic and were lost to follow-up. Of the remaining 58 eyes, 27 (46.6%) underwent cataract surgery during the study period. Cataract type was nuclear sclerosis in every case, and there was no case of cortical or posterior
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subcapsular cataract. All cataract surgeries were successful and uneventful. Neither intraoperative (e.g., lens capsule rupture) nor postoperative (e.g., zonule formation, persistent ocular hypertension) complications were observed during the follow-up period. Table 2 demonstrates the time-course of refractive changes after lens-sparing vitrectomy for rhegmatogenous RD. The operative eyes showed a progressive myopic shift (Figure 1), and the refractions 6 months and later after vitrectomy were significantly different from baseline (P < 0.05, Dunnett’s test). The refractions in the contralateral eyes were stable throughout the study period (Figure 1). There was no significant difference in postoperative spherical equivalent between the operative and contralateral eyes until 3 months after surgery, but the operative eyes were more myopic than the contralateral eyes 3 months or later after lens-sparing vitrectomy (all P < 0.05, Student’s t test). A significant negative correlation was found between time after vitrectomy and spherical equivalent in the operative eyes (R2 = 0.216, P < 0.001), but not in the contralateral eyes (R2 = 0.016, P = 0.78). When comparison of baseline clinical characteristics was performed between patients who underwent cataract surgery in the follow-up period (27 eyes, 46.6%) and patients who did not (31 eyes, 53.4%), patients who underwent cataract surgery were significantly older than patients who did not (50.9 ± 15.1 and 49.7 ± 18.9 respectively, P < 0.001). Differences between these groups relating to sex, ocular side, axial length, preoperative spherical equivalent, and circumferential dimension of retinal tears were not significant (P = 0.52, 0.44, 0.41, 0.45, and 0.26 respectively). Furthermore, when comparisons of intraoperative parameters including operative time, gauge of vitrectomy system, use of wide-angle viewing system, laser photocoagulation number, use of gas tamponade, and best corrected visual acuity were performed between these two groups, significant differences were not observed for any of them (P = 0.79, 0.08, 0.11, 0.16, 0.58, and 0.19 respectively). The progression rate of the refractive spherical equivalent following vitrectomy was significantly correlated with patient age (P < 0.01; Figure 2). However, no significant relationships were found between the spherical equivalent progression rate and axial length (P = 0.14), preoperative spherical equivalent (P = 0.69), retinal tear circumference (P = 0.53), operation time (P = 0.37), or the number of photocoagulation spots (P = 0.61). DISCUSSION Nuclear sclerosis of the crystalline lens is a common complication of lens-sparing vitrectomy, leading to increased lens opacity and myopic shift.15 Various articles have reported nuclear sclerotic changes in vitrectomized eyes with posterior segment diseases.8-14,16,17 The main outcome measure of almost all previous reports was the degree of lens opacity. Although there is one report of refractive change in patients undergoing vitrectomy that progressed to myopia at 3 or 4 months, temporal changes were not observed.18 To the best of our knowledge, the present study is the first to report detailed refractive changes over time, and anisometropia, after lens-sparing vitrectomy. Myopic shifts were first observed 1 month after surgery in the operative
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eyes, and tended to gradually increase each month during the study period. Significant refractive changes in the contralateral eyes were not observed, suggesting that lens-sparing vitrectomy substantially affects lens status from early in the postoperative period. Compared with a previous report, more major myopic shift was seen with -4.03 diopters (D) at 12 months after surgery (-4.97 D at 15 months) in the present study.18 All patients in the present study needed correction of the refractive error by glasses or contact lenses to obtain best corrected visual acuity after surgery. Due to the major refractive changes in this short period after surgery, patients require frequent exchange of their glasses or contact lenses, and it is hard to obtain a stable best corrected visual acuity. Consequently, the longitudinal refractive changes reduce the quality of vision in daily life, even in cases with good visual acuity after surgery. Additionally, similar results were observed with regard to the time-course of anisometropic refractive changes. The difference in refractive power between the operative eye and the contralateral eye was statistically significant at 3 months and later after vitrectomy, and >3 D of anisometropia was observed at 6 months after surgery, which was more pronounced at 15 months after surgery. Brooks and associates21 reported that binocular visual function also deteriorates proportionally with the degree of anisometropia, even when only a 1-D anisometropia exists. However, it remains unclear what level of anisometropia requires correction in healthy adults. The above-mentioned reports suggest that patients who have undergone lens-sparing vitrectomy may develop binocular and stereoscopic vision deficits from anisometropia, even if they have good visual acuity in both eyes.19-21 In order to achieve the optimal quality of vision after vitrectomy, both best-corrected visual acuity and interocular refractive differences (i.e., anisometropia) in the early postoperative period should be considered while assessing changes over time. In the present study, cataract surgery was performed in 27 of 58 eyes (46.6%) during the study follow-up period. In a previous study,11 cataract surgery was also performed in 47% of vitrectomized patients during the initial 15 months after surgery. Various analyses have been performed to determine which factors are correlated with cataract progression after lens-sparing vitrectomy, but the significant associated factors remain unclear to date. It has been reported that several factors are associated with cataract progression after lens-sparing vitrectomy, and some reports have suggested that patient age is the most important factor.14,22 Melberg and Thomas22 showed that the 2-year incidence of post-vitrectomy nuclear sclerosis for patients younger than 50 years of age was 7%, significantly lower than the 79% incidence in patients older than 50 years of age. Thompson14 reported that the nuclear sclerosis scores of vitrectomized eyes of patients younger than 50 years showed minimal increases, whereas eyes of patients older than 50 years showed similar increases related to nuclear sclerosis. The present study examined various factors potentially associated with cataract progression, including patients’ clinical characteristics, intraoperative parameters, and postoperative complications, and the only parameter significantly associated with cataract progression was patient age, as has been previously reported.14,22,23 Previous reports have investigated intraoperative parameters including the gauge of the vitrectomy system,
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operation time, and the use of gas tamponade.14,24,25 However, none of these intraoperative parameters were significantly associated with cataract progression. Age is one of the important factors of cataract progression.26 In the present study, myopia following lens-sparing vitrectomy significantly progressed with age. This suggests that age remains a significant risk factor for cataract progression, even after lens-sparing vitrectomy. In the present study, almost all patients aged older than 50 years exhibited a myopic shift (Figure 2). The result that an age of approximately 50 years represented a threshold for cataract progression in vitrectomized eyes was concordant with the results of previous studies.14,22 Whereas, in age-related nuclear cataract, the increase in prevalence of lens opacities is gradual, particularly until the age of 60 years, and resembles an exponential curve with a relatively sharp increase in prevalence at the age of approximately 60 years.26 The difference in threshold age of nuclear cataract progression between age-related cataract and vitrectomy induced cataract is significant; however, it is currently not known whether the mechanism of cataract progression after lens-sparing vitrectomy is the same as that of the progression of age-related nuclear cataract. If cataract progression after lens-sparing vitrectomy has pathogenic mechanisms similar to those of age-related nuclear cataract, in considering the pathogenic mechanism of cataract progression, three possible mechanisms have been proposed: intraoperative light toxicity, intraoperative lens protein oxidation, and surgically-induced alteration of the lens’ biochemical microenvironment. Holekamp and associates27 proposed the hypothesis that increased exposure to oxygen is responsible for nuclear cataract progression as well as age-related cataract progression, and the vitreous oxygen tension in patients with ischemic diabetic retinopathy was significantly lower in their study, which may be responsible for the lower prevalence of nuclear sclerotic cataract. They also reported that partial oxygen pressure was significantly higher after vitrectomy, which resulted in oxidative damage to the crystalline lens.28 In addition, they noted the role of vitreous ascorbate, which consumes oxygen and plays an important role in maintaining the low oxygen environment of the normal vitreous cavity.27 In fact, the ascorbate concentration in human vitreous is more than 30 times that in blood.29 Vitrectomy replaces the vitreous with saline, simultaneously decreasing levels of ascorbate and increasing levels of oxygen, which may accelerate nuclear sclerotic cataract progression. If the liquefaction and removal of the vitreous is related to nuclear sclerosis progression, nonvitrectomizing vitrectomy, which leaves as much vitreous as possible, might be effective for preventing cataract progression.30 Nonvitrectomizing vitrectomy is useful in patients with epiretinal membrane. It may also be that vitrectomy for rhegmatogenous RD, which requires the complete removal of the vitreous, might accelerate nuclear sclerotic cataract progression more than vitrectomy for epiretinal membrane. Further study is needed to determine the relationship between remaining vitreous humor and vitreous cavity oxygen levels, and how this relates to cataract formation. Treatment for rhegmatogenous RD commonly involves not only vitrectomy but also scleral buckling. There are no significant differences in
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anatomical success rate between the two surgical procedures, whereas in a multicenter clinical study, cataract progression rate was significantly lower in the scleral buckling group.31 This result suggests that refractive change due to nuclear sclerotic cataract may be limited in patients with rhegmatogenous RD who undergo scleral buckling. In patients aged older than 50 years who underwent lens-sparing vitrectomy, weaknesses including reduced accommodative power, increased crystalline lens aberrations, and rapid nuclear sclerotic myopia progression have been reported.21,22,32,33 These reports may lead to a conclusion that lens-sparing vitrectomy causes the loss of crystalline lens function early in the postoperative period. It is reasonable to surmise that scleral buckling is the preferable method in terms of preservation of crystalline lens function, except in cases such as media opacity, and multiple or undetermined breaks. However, there have been no reports of long-term refractive changes after scleral buckling for rhegmatogenous RD, and further studies are required to evaluate its effects on nuclear sclerotic progression of crystalline lens. A limitation of this study is that refractive power after vitrectomy is influenced by multiple factors. Vitrectomy causes changes in the crystalline lens, corneal topography, and axial length, all of which influence total ocular refractive values.34,35 Furthermore, all refractions in the current study were performed prior to mydriasis. Although the effects of accommodation should have been minimal in our mostly older study population, future studies with mydriatic refractions should be performed to obtain more precise data.21,32 Another potential study limitation is that cataract surgery was performed on the basis of a patient’s subjective decision, and not on predefined clinical criteria. Therefore, some patients with substantial visual loss or anisometropia, in whom cataract surgery was indicated, did not undergo the procedure. A prospective study with objective assessments of crystalline lens changes and objective criteria for cataract surgery would have been preferable. In conclusion, refractive changes after lens-sparing vitrectomy for rhegmatogenous RD consistently progressed during the study period. Because postoperative anisometropia occurred 3 months after surgery, it is likely that it degrades binocular visual function early in the postoperative period. The only risk factor associated with cataract progression after lens-sparing vitrectomy was patient age.
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a. Funding/Support: No author has received public or private funding support for this research. b. Financial Disclosures: No author has any relevant financial disclosures to declare. c. Author Contributions: Design of the study (Y.O, F.O., T.H., T.O.); conduct of the study (Y.O., F.O., T.H.); data collection (Y.O.); management, analysis, and interpretation of the data (Y.O., F.O.); preparation of the manuscript (Y.O.); review of the manuscript (T.O.); approval of the manuscript (Y.O., F.O., T.H., T.O.). d. Other Acknowledgments: None.
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References 1. Machemer R, Parel JM, Buettner H. A new concept for vitreous surgery. 1. Instrumentation. Am J Ophthalmol 1972;73(1):1-7. 2. O'Malley C, Heintz RM Sr. Vitrectomy with an alternative instrument system. Ann Ophthalmol 1975;7(4):585-588,591-594. 3. de Juan E Jr, Hickingbotham D. Refinements in microinstrumentation for vitreous surgery. Am J Ophthalmol 1990;109(2):218-220. 4. Fujii GY, de Juan E Jr, Humayun MS, et al. A new 25-gauge instrument system for transconjunctival sutureless vitrectomy surgery. Ophthalmology 2002;109(10):1807-1812. 5. Eckardt C. Transconjunctival sutureless 23-gauge vitrectomy. Retina 2005;25(2):208-211. 6. Lakhanpal RR, Humayun MS, de Juan E Jr, et al. Outcomes of 140 consecutive cases of 25-gauge transconjunctival surgery for posterior segment disease. Ophthalmology 2005;112(5):817-824. 7. Michels RG, Ryan SJ Jr. Results and complications of 100 consecutive cases of pars plana vitrectomy. Am J Ophthalmol 1975;80(1):24-29. 8. Cherfan GM, Michels RG, de Bustros S, Enger C, Glaser BM. Nuclear sclerotic cataract after vitrectomy for idiopathic epiretinal membranes causing macular pucker. Am J Ophthalmol 1991;111(4):434-438. 9. Thompson JT, Glaser BM, Sjaarda RN, Murphy RP. Progression of nuclear sclerosis and long-term visual results of vitrectomy with transforming growth factor beta-2 for macular holes. Am J Ophthalmol 1995:119(1);48-54. 10. Schachat AP, Oyakawa RT, Michels RG, Rice TA. Complications of vitreous surgery for diabetic retinopathy. II. Postoperative complications. Ophthalmology 1983;90(5):522-530. 11. de Bustros S, Thompson JT, Michels RG, Enger C, Rice TA, Glaser BM. Nuclear sclerosis after vitrectomy for idiopathic epiretinal membranes. Am J Ophthalmol 1988;105(2):160-164. 12. Michels RG. Vitrectomy for macular pucker. Ophthalmology 1984;91(11):1384-1388. 13. Freeman WR, Azen SP, Kim JW, el-Haig W, Mishell DR 3rd, Bailey I. Vitrectomy for the treatment of full-thickness stage 3 or 4 macular holes. Results of a multicentered randomized clinical trial. Arch Ophthalmol 1997;115(1):11-21. 14. Thompson JT. The role of patient age and intraocular gas use in cataract progression after vitrectomy for macular holes and epiretinal membranes. Am J Ophthalmol 2004;137(2):250-257. 15. Kawakubo H, Sato Y, Shimada H, et al. Myopic change in refraction due to nuclear sclerotic changes after vitreous surgery (comparison of epimacular membrane and macular hole). Folia Ophthalmol Jpn 1996;47(4):396-400. 16. Wong SC, Clare G, Bunce C, Sullivan PM, Gregor ZJ, Ezra E. Cataract progression in macular hole cases: results with vitrectomy or with observation. J Cataract Refract Surg. 2012;38(7):1176-1180. 17. Ogura Y, Takanashi T, Ishigooka H, Ogino N. Quantitative analysis of lens changes after vitrectomy by fluorophotometry. Am J Ophthalmol 1991;111(2):179-183.
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18. Tseng PC, Woung LC, Tseng GL, et al. Refractive change after pars plana vitrectomy. Taiwan J Ophthalmol 2012;2(1):18-21. 19. Okamoto F, Nakano S, Oshika T. Truncated contact lenses for peripheral vitrectomy. Retina 2012;32(8):1682-1684. 20. Brooks SE, Johnson D, Fischer N. Anisometropia and binocularity. Ophthalmology 1996;103(7):1139-1143. 21. Richdale K, Sinnott LT, Bullimore MA, et al. Quantification of age-related and per diopter accommodative changes of the lens and ciliary muscle in the emmetropic human eye. Invest Ophthalmol Vis Sci 2013;54(2):1095-1105. 22. Melberg NS, Thomas MA. Nuclear sclerotic cataract after vitrectomy in patients younger than 50 years of age. Ophthalmology 1995;102(10):1466-1471. 23. Smiddy WE, Feuer W. Incidence of cataract extraction after diabetic vitrectomy. Retina 2004;24(4):574-581. 24. Cheng L, Azen SP, El-Bradey MH, et al. Duration of vitrectomy and postoperative cataract in the vitrectomy for macular hole study. Am J Ophthalmol 2001;132(6):881-887. 25. Almony A, Holekamp NM, Bai F, Shui YB, Beebe D. Small-gauge vitrectomy does not protect against nuclear sclerotic cataract. Retina 2012;32(3):499-505. 26. Richter GM, Torres M, Choudhury F, Azen SP, Varma, R. Risk factors for cortical, nuclear, posterior subcapsular, and mixed lens opacities: the Los Angeles Latino Eye Study. Ophthalmology 2012;119(3):547-554. 27. Holekamp NM, Bai F, Shui YB, Almony A, Beebe DC. Ischemic diabetic retinopathy may protect against nuclear sclerotic cataract. Am J Ophthalmol 2010;150(4):543-550. 28. Holekamp NM, Shui YB, Beebe DC. Vitrectomy surgery increases oxygen exposure to the lens: a possible mechanism for nuclear cataract formation. Am J Ophthalmol 2005;139(2):302-310. 29. Shui YB, Holekamp NM, Kramer BC, et al. The gel state of the vitreous and ascorbate-dependent oxygen consumption: relationship to the etiology of nuclear cataracts. Arch Ophthalmol 2009;127(4):475-482. 30. Sawa M, Ohji M, Kusaka S, et al. Nonvitrectomizing vitreous surgery for epiretinal membrane long-term follow-up. Ophthalmology 2005;112(8):1402-1408. 31. Heimann H, Bartz-Schmidt KU, Bornfeld N, Weiss C, Hilgers RD, Foerster MH. Scleral buckling versus primary vitrectomy in rhegmatogenous retinal detachment: a prospective randomized multicenter clinical study. Ophthalmology 2007;114(12):2142-2154.
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32. Anderson HA, Hentz G, Glasser A, Stuebing KK, Manny RE. Minus-lens-stimulated accommodative amplitude decreases sigmoidally with age: a study of objectively measured accommodative amplitudes from age 3. Invest Ophthalmol Vis Sci 2008;49(7):2919-2926. 33. Fujikado T, Kuroda T, Ninomiya S, et al. Age-related changes in ocular and corneal aberrations. Am J Ophthalmol 2004;138(1):143-146. 34. Okamoto F, Okamoto C, Sakata N, et al. Changes in corneal topography after 25-gauge transconjunctival sutureless vitrectomy versus after 20-gauge standard vitrectomy. Ophthalmology 2007;114(12):2138-2141. 35. Brazitikos PD, Androudi S, Christen WG, Stangos NT. Primary pars plana vitrectomy versus scleral buckle surgery for the treatment of pseudophakic retinal detachment: a randomized clinical trial. Retina 2005;25(8):957-964.
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Figure 1. Changes in spherical equivalent over time in eyes after lens-sparing vitrectomy for rhegmatogenous retinal detachment. A significant negative correlation was found between time after vitrectomy and spherical equivalent (R2 = 0.216, P < 0.001). However, there was no correlation between time after vitrectomy and refraction in contralateral eyes (R2 = 0.016, P = 0.78). Values are presented as mean ± SE.
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Figure 2 Relationship between age and myopic progression rate after lens-sparing vitrectomy for rhegmatogenous retinal detachment. There was a significant correlation between the progression rate and patient age (P < 0.01).
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50.0 ± 9.9 50/14
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Sex (male/female) Ocular side (left/right)
25/39
Preoperative vitreous hemorrhage (yes/no)
12/52
Axial length (mm) (24 eyes)
26.0 ± 1.9
-5.68 ± 3.71
Circumferential dimension of retinal tears (degrees)
62.3 ± 33.5
Operation time (minutes)
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Macular status (on/off)
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Preoperative spherical equivalent (diopter) (38 eyes)
27/37 51.3 ± 17.4 47/17
Use of wide-angle viewing system (yes/no)
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Gauge of vitrectomy system (23-gauge/25-gauge)
Laser photocoagulation number (shots) Use of gas tamponade (none/air/20% SF6)
783 ± 454 2/13/49 21/42
Occurrence of vitreous hemorrhage (yes/no)
2/62
Occurrence of fibrin reaction (yes/no)
2/62
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Use of triamcinolone acetonide for vitreous visualization (yes/no)
0.23 ± 0.33 (20/34) Values presented as mean ± standard deviation. BCVA = best corrected visual acuity, logMAR = logarithm of minimum angle of resolution BCVA following vitrectomy (logMAR) (Snellen equivalent)
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Table 2. Time-course of refractive changes after lens-sparing vitrectomy for rhegmatogenous retinal detachment Average deviation from baseline (diopter)
Contralateral eyes (diopter)
Degree of Anisometropia (diopter)
P value
0.36
0.49
1.02
0.18
1.15
0.44
-5.65 ± 3.26
2.02
0.05†
-5.42 ± 3.44
3.12
0.005†
-6.00 ± 2.82
3.43
0.04†
-6.25 ± 2.68
3.56
0.05†
-5.51 ± 2.79
5.24
0.03†
-5.78 ± 3.69
-6.14 ± 3.44
1 month
-6.89 ± 4.17
-1.11
-5.87 ± 3.42
2 months
-7.44 ± 2.92
-1.66
-6.29 ± 2.38
3 months
-7.67 ± 4.40
-1.89
6 months
-8.54 ± 4.21*
-2.76
9 months
-9.43 ± 4.17*
-3.65
12 months
-9.81 ± 4.58*
-4.03
15 months
-10.75 ± 4.65*
-4.97
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M AN U
SC
Baseline
RI PT
Operated eyes (diopter)
AC C
Values are presented as mean ± standard deviation. *Statistical difference from baseline (Dunnett’s test). †Statistical difference between operative and contralateral eyes (Student’s t test).
AC C
EP
TE D
M AN U
SC
RI PT
ACCEPTED MANUSCRIPT
AC C
EP
TE D
M AN U
SC
RI PT
ACCEPTED MANUSCRIPT
AC C
EP
TE D
M AN U
SC
RI PT
ACCEPTED MANUSCRIPT
ACCEPTED MANUSCRIPT
Yoshifumi Okamoto graduated from Tsukuba University School of Medicine, Ibaraki, Japan in 2000. He completed his ophthalmology residency at University of Tsukuba Hospital. Dr Okamoto is currently the assistant professor in University of Tsukuba, Department of Ophthalmology. He specializes in vitreoretinal surgery and age-related
AC C
EP
TE D
M AN U
SC
RI PT
macular degeneration.
