Nuclear sclerosis after vitrectomy for idiopathic epiretinal membranes

Comparison of Surgical Times Between Manual and Robot-Assisted Epiretinal Membrane Peeling

Purpose

Epiretinal membranes (ERM) pose a common challenge in vitreoretinal pathology, often causing vision impairment in older adults. The Preceyes Surgical System (PSS) supports the surgical removal of ERM through robot-assisted membrane peeling (RA-MP). This study compares surgical times and iatrogenic hemorrhages between manual membrane peeling (MMP) and RA-MP using PSS.

Methods

Nine patients underwent RA-MP with PSS, whereas 16 patients (18 eyes) underwent MMP for comparative analysis. Surgical durations were categorized into RA-MP, manual forceps utilization in PSS surgeries (mRA-MP), and traditional MMP. Cumulative manual manipulation duration (cMMP), instrument grasps, and intraoperative hemorrhages were statistically analyzed using the Mann-Whitney U test.

Results

RA-MP showed significantly longer peeling times compared to MMP (P < 0.001). Flap initiation grasps were similar between methods (P = 0.86), RA-MP demonstrated a significant reduction in peeling grasps (P = 0.01) and mean grasps per minute (P < 0.001). Although RA-MP resulted in fewer hemorrhages, the difference did not reach statistical significance relative to MMP (P = 0.08).

Discussion

Although RA-MP tended to extend surgical time, it offered advantages in reducing tissue trauma and intraoperative hemorrhages. Further research is needed to explore the learning curve for novice surgeons and evaluate the safety profile of RA-MP.

Translational Relevance

RA-MP may offer potential advantages over manual surgery, particularly in terms of reduced tissue trauma and intraoperative hemorrhages. Despite its longer duration compared with manual techniques, RA-MP may lead to fewer grasping maneuvers and lower rates of hemorrhages, thereby enhancing the safety and precision of vitreoretinal surgeries.

[Epiretinal membrane: diagnostics, indications and surgical treatment]

An epiretinal membrane (ERM) is a frequently occurring disease affecting the macula, which can be associated with visual impairment and metamorphopsia, depending on the severity and location. A distinction is made between an idiopathic form caused by age-related changes of the vitreous body and a secondary form associated with diseases of the posterior segment. The development of fibrocellular epiretinal membranes formed by dedifferentiation of intraretinal and extraretinal cells at the level of the vitreomacular interface plays a major role in the pathogenesis. The diagnostics and indications for surgical treatment of ERM are based on the visual acuity, evidence of metamorphopsia, ophthalmoscopic findings and optical coherence tomography (OCT) of the macula. In addition to the possibility of observation of the course where benign spontaneous courses are not uncommon, pars plana vitrectomy (PPV) with peeling of the ERM and internal limiting membrane (ILM) to prevent recurrences is the treatment of choice in symptomatic patients. The prognosis after surgical treatment is very good. In approximately two thirds of the cases, an improvement in visual acuity and/or a reduction of metamorphopsia can be achieved, with a number of predictive, primarily OCT-based factors enabling a prediction of the functional prognosis. Comprehensive patient education regarding the generally long duration of postoperative rehabilitation and the possibility of persistent symptoms or visual deterioration despite successful membrane removal is essential.

Cataract Formation Following Pars Plana Vitrectomy in the Pediatric Population

PURPOSE

To analyze post-vitrectomy cataract formation in the pediatric population to elucidate the number of phakic children requiring cataract surgery following vitreous surgery and the perioperative factors affecting cataract development in these patients.

METHODS

Eyes of pediatric patients that underwent phakic pars plana vitrectomy (PPV) with no prior cataract in a 10-year period were included. Analyses evaluated relationships between patient age and time to cataract surgery, as well as contributing factors for cataract formation. Final visual outcomes were also examined. Outcomes were collected for patient age at first vitrectomy, indication for vitrectomy, use of tamponade agents, history of ocular trauma, cataract status, and time to cataract surgery from first vitrectomy.

RESULTS

Of 44 eyes analyzed, 27 (61%) were noted to have some degree of cataract formation. Of these, 15 (56%; 34% of total eyes) underwent cataract surgery. Use of octafluoropropane (P = .04) or silicone oil (P = .03) positively correlated with the need for cataract surgery in the total study group. Patients requiring cataract surgery had worse endpoint visual acuities than those who did not undergo surgery (P = .02), although this difference becomes less significant in follow-up over 2 years (P = .30). Patients who had cataracts but did not need cataract surgery showed an improvement in visual acuity (P = .04), but this was not demonstrated in patients who did need cataract surgery (P = .90).

CONCLUSIONS

Pediatric eye care providers should be aware of the significant risk of cataract formation following a phakic PPV. [J Pediatr Ophthalmol Strabismus. 2023;60(6):421-426.].

Pars Plana Vitrectomy Alone or Combined with Phacoemulsification to Treat Rhegmatogenous Retinal Detachment: A Systematic Review of the Recent Literature

Pars plana vitrectomy is today a common first-line procedure for treatment of rhegmatogenous retinal detachment (RRD). Removal or preservation of the natural lens at the time of vitrectomy is associated with both advantages and disadvantages. The combination of cataract extraction (i.e., phacoemulsification) with pars plana vitrectomy (PPVc) enhances visualization of the peripheral retina and the surgical management of the vitreous base. However, PPVc prolongs the surgical time and is associated with iatrogenic loss of the accommodation function in younger patients, possible postoperative anisometropia, and unexpected refractive results. Performance of pars plana vitrectomy alone (PPVa) requires good technical skills to minimize the risk of lens damage, and quickens cataract development. We retrieved all recent papers that directly compared PPVc and PPVa using parameters that we consider essential when choosing between the two procedures (the success rate of anatomical RRD repair, postoperative refractive error, intra- and postoperative complications, and costs). PPVa and PPVc were generally comparable in terms of RRD anatomical repair. PPVc was associated with fewer intraoperative, but more postoperative, complications. Macula-off RRD PPVc treatment was often associated with undesirable myopic refractive error. PPVa followed by phacoemulsification was the most expensive procedure.

Comparison of simultaneous vs sequential pars plana vitrectomy and cataract surgery

BACKGROUND

To compare the clinical outcomes of patients undergoing sequential pars plana vitrectomy (PPV) followed by cataract extraction surgery (CE) [PPV/CE], simultaneous PPV and CE (PPV + CE), and sequential CE followed by PPV [CE/PPV].

METHODS

A retrospective observational cohort study of 427 eyes of 404 patients who underwent either sequential or simultaneous PPV and CE surgery between March 2016 and May 2021. Pre-operative and post-operative assessments (up to 2 years of follow-up visits) of uncorrected visual acuity (UCVA), corrected distance visual acuity (CDVA), spherical equivalent (SEQ), and refractive prediction error (RPE) was done. Main outcome measures were both visual (UCVA, CDVA) and refractive (RPE, SEQ).

RESULTS

There was a statistically significant difference in CDVA of the PPV/CE, PPV + CE, CE/PPV groups (logMAR 0.34 ± 0.40, 0.65 ± 0.61, and 0.55 ± 0.60, respectively) at one month postoperatively (POM1) (P < 0.001), and at the POM12 visits (logMAR 0.25 ± 0.34, 0.53 ± 0.68, and 0.44 ± 0.48; P = 0.04). In the subgroup analysis of patients with a diagnosis of either epiretinal membrane or vitreous opacities, there was no statistically significant difference in SEQ (P = 0.09) and RPE (P = 0.13) at the combined 1 month and 3 month visits.

CONCLUSION

Simultaneous PPV and cataract surgery demonstrated similar improvements in visual acuity and refractive outcomes, as well as comparable intraoperative and postoperative complication profiles to sequential surgery.

Outcomes of Retinectomy without Lensectomy in Rhegmatogenous Retinal Detachments with Proliferative Vitreoretinopathy

PURPOSE

To report the anatomic and functional outcomes of retinectomy without lensectomy in eyes with rhegmatogenous retinal detachment (RRD) and proliferative vitreoretinopathy (PVR).

DESIGN

Retrospective, noncomparative, and interventional case series.

SUBJECTS

One hundred twelve eyes of 112 patients with RRD complicated by PVR who underwent retinectomy without lensectomy.

METHODS

Retrospective review of patients treated with vitrectomy and retinectomy without lensectomy from January 1, 2015, to January 1, 2020.

MAIN OUTCOME MEASURES

The primary outcome was the final attachment rate and single surgery anatomic success (SSAS) at 3 and 6 months after retinectomy. Secondary outcomes included predictors of final visual acuity (VA), the mean number of subsequent operations required for complete retinal reattachment, cataract surgery, and the number of eyes that ultimately had successful silicone oil removal.

RESULTS

Complete final retinal reattachment was achieved in 111 of 112 (99.1%) patients, with a mean (standard deviation [SD]) follow-up of 29 (14) months (range, 8-62 months) after retinectomy. The SSAS was achieved in 84 of 112 (75%) patients at 3 months and 73 of 112 (65.2%) patients at 6 months. The final VA improved or stabilized in 76 of 112 (67.9%) eyes. Silicone oil removal was performed in 72 of 112 patients (64.3%) at a mean (SD) of 6.6 (3.3) months, and cataract surgery was performed on 101 (90.2%) eyes before the last follow-up visit.

CONCLUSIONS

Retinectomy without lensectomy to repair RRDs complicated by PVR showed acceptable anatomic and functional results. This study suggests that removing the lens when there is no significant cataract may not be necessary in these cases to obtain reasonable outcomes.

Cataract progression following lens-sparing pars plana vitrectomy for rhegmatogenous retinal detachment

Lens-sparing pars plana vitrectomy (PPV) is often followed by cataract development. However, there have been few prospective studies evaluating the timing of cataract progression and potential associated factors. This was an observational study conducted at the Ophthalmology Unit of the University Hospital of Parma (Parma, Italy). Patients presenting with rhegmatogenous retinal detachment (RRD), who underwent PPV with preservation of the lens, were examined according to a scheduled follow-up (3, 6 and 12 months after PPV) and then preoperatively when cataract extraction surgery (CES) was indicated, or at the end of the study follow-up period (May 2021). The primary outcome was the interval between PPV and CES indication (based on predefined refractive criteria). A total of 36 eyes of 36 patients (mean age: 52 ± 10 years) were included in the study. Nineteen eyes (53%) were indicated for CES a median of 14.5 months (IQR: 12.0-24.8) after PPV. The nuclear and posterior subcapsular forms of cataract progressed significantly starting at 6 months after PPV. Older age at the time of PPV, silicone oil tamponade and RRD without macular involvement were significantly and independently associated with an earlier indication for CES. Patient age and the use of silicone oil tamponade must be taken into consideration when evaluating the risk of cataract development after PPV.

The Postvitrectomy Cataract

To review the recent literature regarding risk factors for cataract formation after vitrectomy, the challenges and management strategies for anterior segment surgeons when facing post-vitrectomy cataract surgery, and the visual outcomes of patients undergoing post-vitrectomy cataract surgery. Cataract surgery after vitrectomy can be safely performed to significantly improve the visual outcome in most post-vitrectomy patients, although final visual acuity is primarily limited by the patient’s underlying vitreoretinal pathology.

Evaluation of the effects of vitrectomy with primary epiretinal membrane peel on optical quality using double-pass aberrometry

INTRODUCTION

We performed a prospective, single-center, cohort study in order to evaluate the effects of vitrectomy with epiretinal membrane (ERM) peel on optical quality in patients with primary ERM.

METHODS

Thirty patients treated for primary ERM by vitrectomy with ERM peel were included from our tertiary university hospital ophthalmology department. The main study outcome was variation in optical quality parameters measured using the HD Analyzer™ between pre-operative and two-month post-operative evaluations in operated eyes. Optical quality parameters comprised point spread function (PSF) width at 10% and 50%, objective scatter index (OSI), and modulation transfer function (MTF) cutoff. Contralateral non-operated eyes were used as an internal control for measurement reproducibility.

RESULTS

Mean PSF width at 10% (42.22 vs 27.37 arc/min; p = 0.0002) and mean OSI (3.32 vs 2.32; p = 0.0003) were significantly improved between pre- versus post-operative evaluations. Mean PSF width at 50% and mean MTF cutoff showed no changes. Subgroup analysis according to crystalline lens status gave similar results demonstrating that improvements in mean PSF width at 10% and OSI were not lens-related. Non-operated eyes showed no changes in any of the parameters analyzed.

CONCLUSION

Reduced light scattering measured by OSI indicates improved optical quality following vitrectomy with ERM peel among patients with primary ERM. OSI measurement could thus be a new parameter of interest in the pre-operative assessment of primary ERM and other pre-vitrectomy assessments.

Two-year Changes in Postoperative Central Macular Thickness and Subfoveal Choroidal Thickness in Epiretinal Membrane Patients

Purpose: To evaluate changes in central macular thickness (CMT) and subfoveal choroidal thickness (SFCT) after phacovitrectomy over a 2-year period in idiopathic epiretinal membrane (ERM) patients.Methods: The records of 52 idiopathic ERM patients (52 eyes) who underwent phacovitrectomy, without recurrence of the condition over a 2-year follow-up period, were reviewed retrospectively. Changes in CMT and SFCT, as measured by optical coherence tomography, were analyzed and compared with those of a normal control group over a 2-year period.Results: The mean preoperative CMT and SFCT were 425.67 ± 84.67 and 257.56 ± 90.13 μm, respectively. Postoperative CMT was reduced significantly to 372.17 ± 45.26 μm at 1 year and 363.15 ± 47.35 μm at 2 years (p < 0.001). SFCT at 1 and 2 years postoperatively was significantly reduced to 238.85 ± 84.85 and 230.31 ± 87.95 μm, respectively (p < 0.001). In the control group, there was no significant change in CMT; however, the SFCT decreased by 11.09 ± 22.36 μm during the 2-year follow-up (p = 0.007). In contrast, in the patient group, CMT and SFCT decreased by 62.52 ± 71.45 and 27.25 ± 41.97 μm, respectively, showing a significant difference from the control group (p < 0.001 and p = 0.043, respectively). Both before surgery and at 1 year postoperatively, the thinner the CMT, the better the best-corrected visual acuity (BCVA) (p = 0.010 and p = 0.018, respectively). A better postoperative BCVA at 2 years was associated with a thinner CMT and better BCVA before surgery (p < 0.001 and p < 0.001, respectively).Conclusions: Following a phacovitrectomy procedure, ERM patients showed significant reductions in both the CMT and SFCT at the 2-year follow-up.

Inner Retinal Morphology and Visual Outcomes in Idiopathic Epiretinal Membrane Surgery: A Retrospective Optical Coherence Tomography Study

Purpose:

Epiretinal membrane (ERM) is a common retinal finding for patients older than 50 years. Disorganization of the retinal inner layers (DRIL) has emerged as a novel predictor of poor visual acuity (VA) in eyes with inner retinal pathology. The aim of our study is to correlate preoperative DRIL with visual outcomes after ERM surgery.

Methods:

Medical records and optical coherence tomography (OCT) images of 81 pseudophakic patients who underwent treatment of idiopathic ERM were reviewed. Preoperative DRIL on OCT was correlated with VA at baseline and at 3 and 6 months after ERM surgery. DRIL was defined as the loss of distinction between the ganglion cell–inner plexiform layer complex, inner nuclear layer, and outer plexiform layer. DRIL severity was based on its extent within the central 2-mm region of a transfoveal B-scan (absent/mild: <one-third, severe: >one-third horizontal width).

Results:

Review of preoperative OCT showed severe DRIL in 41% and absent/mild DRIL in 59%. Severe DRIL was associated with worse baseline VA ( P < .001). Preoperative VA and DRIL status at baseline were both predictors of postoperative VA at follow-up time points ( P < .001). Severe DRIL was associated with significantly less improvement in VA at 6 months (–0.23 logMAR for absent/mild vs –0.14 for severe DRIL).

Conclusions:

Presence of severe preoperative DRIL correlates with worse baseline VA in patients with ERM and reduced VA improvement at 6 months. DRIL can be a strong predictor of long-term poor visual outcomes in ERM surgery.

Hyperbaric oxygen as a model of lens aging in the bovine lens: The effects on lens biochemistry, physiology and optics

Age related nuclear (ARN) cataracts in humans take years to form and so experimental models have been developed to mimic the process in animals as a means of better understanding the etiology of nuclear cataracts in humans. A major limitation with these animal models is that many of the biochemical and physiological changes are not typical of that seen in human ARN cataract. In this review, we highlight the work of Frank Giblin and colleagues who established an in vivo animal model that replicates many of the changes observed in human ARN cataract. This model involves exposing aged guinea pigs to hyperbaric oxygen (HBO), which by causing the depletion of the antioxidant glutathione (GSH) specifically in the lens nucleus, produces oxidative changes to nuclear proteins, nuclear light scattering and a myopic shift in lens power that mimics the change that often precedes cataract development in humans. However, this model involves multiple HBO treatments per week, with sometimes up to a total of 100 treatments, spanning up to eight months, which is both costly and time consuming. To address these issues, Giblin developed an in vitro model that used rabbit lenses exposed to HBO for several hours which was subsequently shown to replicate many of the changes observed in human ARN cataract. These experiments suggest that HBO treatment of in vitro animal lenses may serve as a more economical and efficient model to study the development of cataract. Inspired by these experiments, we investigated whether exposure of young bovine lenses to HBO for 15 h could also serve as a suitable acute model of ARN cataract. We found that while this model is able to exhibit some of the biochemical and physiological changes associated with ARN cataract, the decrease in lens power we observed was more characteristic of the hyperopic shift in refraction associated with ageing. Future work will investigate whether HBO treatment to age the bovine lens in combination with an oxidative stressor such as UV light will induce refractive changes more closely associated with human ARN cataract. This will be important as developing an animal model that replicates the changes to lens biochemistry, physiology and optics observed in human ARN cataracts is urgently required to facilitate the identification and testing of anti-cataract therapies that are effective in humans.

Drain fluid cryo-explant technique for treatment of superior bullous rhegmatogenous retinal detachment in young adults

Purpose:

To evaluate the efficacy of the drain fluid cryo-explant (DFCE) technique for the management of uncomplicated superior bullous rhegmatogenous retinal detachment (RRD) in young adults.

Patients and methods:

A retrospective study that included eyes with uncomplicated superior bullous RRD in patients ⩽40 years old. DFCE technique consists of sequential drainage of subretinal fluid, intravitreal fluid injection, cryotherapy, and placement of a scleral explant(s). The primary outcome measure was anatomical reposition of the retina after a single surgery. Secondary outcome measures included improvement in best corrected visual acuity (BCVA) and any reported complication related to the procedure.

Results:

The study included 51 eyes which met the study eligibility criteria. The mean duration of detachment was 19.7 ± 6.4 days. A single retinal break was found in 31 eyes (60.8%), and more than one break were found in 20 eyes (39.2%). The mean number of breaks per eye was 1.72 ± 1.04. The mean detached area per eye was 7.21 ± 3.19 clock hours, and the macula was detached in 22 eyes (43.1%). Flattening of the retina and closure of all retinal breaks was achieved in all eyes after a single surgery. Late recurrence of retinal detachment occurred in two eyes (3.9%) due to proliferative vitreoretinopathy (PVR). No complicated cataract or iatrogenic retinal breaks were detected in all eyes.

Conclusion:

DFCE technique could be effectively used for treatment of uncomplicated superior bullous RRD in adults ⩽40 years. It is safe and provides good visualization during surgery with no iatrogenic retinal breaks or complicated cataract.

Vitreoretinal surgeons' experience and time interval from pars-plana vitrectomy to cataract extraction

AIM

To identify the association of the vitreoretinal surgeons' experience with the time interval between pars-plana vitrectomy (PPV) and cataract extraction (CE).

METHODS

Eyes with prior PPV and following CE were included in this retrospective cohort study. The years of practice and the annual case volume were used to describe the surgeons' experience. Multivariable linear regression analysis was used to investigate the relationship between surgeons' experience and the time interval adjusted for the patients age, gender, intraocular tamponade, and case complexity.

RESULTS

Of 132 430 eyes, 1445 eyes were included in this study. In multivariable linear regression analysis, cases performed by surgeons with >20 practice years had longer time intervals compared with surgeons with <10 practice years after adjusted for other variables (β=0.329, 95%CI: 0.113 to 0.549, P=0.003). No difference in time interval was detected for comparing the lowest with the highest volume groups (β=0.089, 95%CI: -0.164 to 0.343, P=0.343). The surgeons' practice years were not directly with the volume. For complicated surgery, the higher-practice-year surgeons had longer time interval than lower-practice-year surgeons.

CONCLUSION

The time intervals from PPV to CE is longer in higher-practice-year surgeons. The surgeons' practice years may have a greater effect on the time interval than annual case volume in high-complexity cases. Matching the complexity of vitreoretinal diseases with the surgeons' practice year should be considered.

Accuracy of New Generation Intraocular Lens Calculation Formulas in Vitrectomized Eyes

PURPOSE

To compare the prediction accuracy of new intraocular lens (IOL) calculation formulas (Barrett Universal II [BUII], Emmetropia Verifying Optical [EVO], Kane and Ladas Super formula) and traditional formulas (Haigis, Hoffer Q, Holladay 1, and SRK/T) with Wang-Koch (WK) axial length (AL) adjustment in vitrectomized eyes.

DESIGN

Retrospective consecutive case-series study.

METHODS

One hundred eleven eyes of 111 patients underwent uneventful phacoemulsification and enVista MX60 implantation after vitrectomy were enrolled and divided into 4 groups according to whether the vitreous cavity was filled with silicone oil. The performance of each formula was evaluated with or without lens constant optimization.

RESULTS

Before lens constants optimization, the mean prediction errors (MEs) of all formulas were statistically different from zero (0.14-0.46 diopters [D]) in vitrectomized eyes, except for the Kane formula. The BUII, EVO, Kane, and Haigis had relatively lower mean absolute error (MAE) and median absolute error (MedAE) with optimized constants. No significant systemic bias was found in new formulas for vitrectomized eyes with AL >26 mm (P > .05). The Hoffer Q and Holladay 1 displayed significantly hyperopic shift (0.39 and 0.51 D) for long eyes, which was corrected by the WK adjustment. There were no significant differences in the prediction accuracy of all formulas among 4 subgroups (P > .05).

CONCLUSIONS

The BUII, EVO, Kane, and Haigis displayed comparable performance in vitrectomized eyes with optimized constants. In vitrectomized highly myopic eyes, the new formulas and traditional formulas with WK adjustment exhibited satisfactory prediction accuracy. Silicone oil tamponade did not affect the prediction accuracy of formulas using IOLMaster 700.

Glutathione Improves the Antioxidant Activity of Vitamin C in Human Lens and Retinal Epithelial Cells: Implications for Vitreous Substitutes

PURPOSE

Tissues in the eye are particularly susceptible to oxidative damage due to light exposure. While vitamin C (ascorbic acid) has been noted as a vital antioxidant in the vitreous humor, its physiological concentration (1-2 mM) has been shown to be toxic to retinal and lens epithelial cells in in vitro cell culture. We have explored adding vitamin C to hydrogel vitreous substitutes as a potential therapeutic to prevent oxidative damage to intraocular tissues after vitrectomy. However, vitamin C degrades rapidly even when loaded at high concentrations, limiting its long-term effectiveness. Glutathione, another antioxidant found abundantly in the lens at concentrations of 2-10 mM, was proposed to be used in conjunction with vitamin C.

METHODS

Cell viability and reactive oxygen species activity of human retinal and lens epithelial cells treated with various combinations of vitamin C, glutathione, hydrogen peroxide, and a hydrogel vitreous substitute were determined using CellTiter-Glo luminescent cell viability assay and dichlorofluorescein assay, respectively. The vitamin C remaining in hydrogel vitreous substitute or glutathione-vitamin C solutions was determined using a microplate reader at 265 nm wavelength, compared against standard solutions with known concentrations.

RESULTS

Glutathione protected the lens and retinal cells from the negative effect of vitamin C on cell viability and prolonged the antioxidant effect of vitamin C in vitro. While the detected reading of pure vitamin C solution decreased rapidly from 100% to 10% by 3 days, glutathione provided a significant extension to vitamin C stability, with 70% remaining after 14 days when the glutathione was used at physiological concentrations found in the lens (2-10 mM).

CONCLUSIONS

These results indicate glutathione might be an effective addition to vitamin C in intraocular implants, including potential vitreous substitutes, and warrants additional studies on the effectiveness of the vitamin C - glutathione combination in preventing oxidative stress post-vitrectomy.

Combined Femtosecond Laser-Assisted Cataract Surgery and 27-Gauge Transconjunctival Sutureless Vitrectomy

Purpose

To report the outcomes of combined surgery using femtosecond laser-assisted cataract surgery (FLACS) and sutureless 27-gauge pars plana vitrectomy with intravitreal tamponade.

Methods

This retrospective clinical study involved 23 eyes of 23 patients on whom combined vitreoretinal surgery was performed. Patients were initially given the femtosecond laser treatment that was performed after selection of capsulotomy and lens fragmentation patterns. The capsulotomy diameter was chosen as 4.9 mm in all patients. After the femtosecond laser, the sutureless phacovitrectomy procedure was performed. At the end of surgery, perfluoropropane or sterile air tamponade was applied.

Results

The mean age of patients was 66.43 ± 7.61 (range, 54–83) years. Fifteen patients were females (65.2%). The mean follow-up was 16.09 ± 4.71 (range, 9–25) months. The most common surgical indication was epiretinal membrane (65.3%). The mean preoperative best-corrected visual acuity (BCVA) was 0.71 ± 0.44 (range, 1.7–0.3) logMAR, and the mean postoperative BCVA at 6 months was 0.16 ± 0.14 (range, 0.4–0) logMAR (p < 0.001). The mean target sphere refractive error was −0.24 ± 0.16 (range, −0.50–0.11) D, and the mean postoperative spherical equivalent refractive error was −0.14 ± 0.39 (range, −1.00–0.50) D at 6 months (p=0.196). All intraocular lenses (IOLs) remained well centered in the capsular bag during surgery and follow-up. There was no iris capture, posterior synechiae, capsular opacification, or pseudophakic cystoid macular edema. The only complication related to femtosecond laser was two cases of subconjunctival haemorrhage related with suction.

Conclusions

FLACS is a safe and effective technique providing the advantage of repeatable, precise capsulorhexis shape and size to achieve a well-centered and stable IOL postoperatively. These advantages can certainly improve the results of vitrectomy, especially in gas-filled eyes. FLACS and 27-gauge sutureless combined surgery may be a future trend in appropriate cases.

Intraocular Oxygen and Antioxidant Status: New Insights on the Effect of Vitrectomy and Glaucoma Pathogenesis

PURPOSE

The purpose of this study was to investigate correlations of partial pressure of oxygen (pO₂) in the ocular anterior segment of human eyes and aqueous humor antioxidant levels of ascorbate (AsA) and total reactive antioxidant potential (TRAP) with glaucoma and vitreous status.

METHODS

This prospective, cross-sectional study stratified patients (n = 288 eyes) by lens and vitreous status and the presence of primary open-angle glaucoma for statistical analyses. Intraocular pO₂ concentrations were measured using a fiberoptic probe in patients at the beginning of planned glaucoma and/or cataract surgery. Aqueous humor specimens were obtained for antioxidant analysis of AsA and TRAP.

RESULTS

Following prior pars plana vitrectomy, pO₂ levels were significantly higher than in the reference group of cataract surgery in the anterior chamber angle (16.2 ± 5.0 vs. 13.0 ± 3.9 mm Hg; P = .0171) and in the posterior chamber (7.6 ± 3.1 vs. 3.9 ± 2.7 mm Hg; P < .0001). AsA and TRAP levels were significantly lower (1.1 ± 0.4 vs. 1.4 ± 0.5 mM, respectively; 403.3 ±116.5 vs. 479.0 ± 146.7 Trolox units, respectively; P = .004 and P = .024, respectively) in patients after vitrectomy. In patients with an intact vitreous, neither pO₂ nor antioxidant status correlated with lens status or glaucoma.

CONCLUSIONS

Increased pO₂ and antioxidant depletion following vitrectomy suggests an alteration of the intraocular oxidant-antioxidant balance. Our study links physiologic factors such as increased pO₂ in the anterior chamber angle and the posterior chamber to decreased antioxidant levels in aqueous humor following vitrectomy. Oxidative stress/damage to the trabecular meshwork in such post-vitrectomy cases may contribute to intraocular pressure elevation and increased risk of glaucoma. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Short-term outcomes of combined pars plana vitrectomy for epiretinal membrane and phacoemulsification surgery with multifocal intraocular lens implantation

Purpose

The purpose of this study was to evaluate the functional and anatomical outcomes of combined phacovitrectomy with multifocal intraocular lens (mfIOL) implantation.

Methods

Retrospective, interventional, non-comparative case series of six eyes that received a combined phacoemulsification surgery with apodized, diffractive mfIOL implantation for cataract and pars plana vitrectomy (PPV) with membrane peeling for epiretinal membrane (ERM). Outcome measures included distance and near visual acuities (DVA and NVA), central macular thickness (CMT), intraocular pressure (IOP), and disruption of external limiting membrane (ELM) or inner-segment outer-segment (IS/OS) junction.

Results

Mean logMAR glare DVA improved from 0.40 (Snellen 20/50) preoperatively to a mean uncorrected DVA of 0.038 (Snellen 20/22) (P=0.004) at 6 months after surgery. All eyes achieved NVA of J2 or better by 12 months postoperatively. Median CMT improved by 10 µm and mean IOP increased by 1 mmHg at 12 months postoperatively. Percentage of patients with ELM or IS/OS disruptions decreased from 66.7% to 33.3%. Two eyes demonstrated residual metamorphopsia on Amsler grid testing postoperatively. Postoperatively, four eyes required laser capsulotomy and one required LASEK for refractive correction.

Conclusion

Combined phacovitrectomy, membrane peeling, and mfIOL implantation improved VA in patients with idiopathic ERM. Multifocality was achieved, but final visual outcome was delayed due to posterior capsular opacification and macular healing.

DNA hypermethylation-mediated downregulation of antioxidant genes contributes to the early onset of cataracts in highly myopic eyes

High myopia is recognized as a risk factor for earlier onset of nuclear cataracts. One possible explanation for this is that lenses in highly myopic eyes are exposed to higher levels of oxygen than normal eyes owing to earlier vitreous liquefaction and, hence, are subjected to oxidative insults. Here, we first compared the methylation levels of six essential antioxidant genes (GSTP1, NRF2, OGG1, TXN, TXNRD1 and TXNRD2) between highly myopic cataract (HMC) and age-related cataract (ARC) lens epithelial samples via Sequenom MassARRAY. We found that specific CpG units in the promoters of GSTP1 and TXNRD2 were hypermethylated and that the expression levels of these two genes were lower in the HMC group than in the ARC group. A luciferase reporter assay confirmed the significance of differentially methylated fragments in the activation of transcription. The importance of GSTP1 and TXNRD2 in antioxidant capacity was confirmed by overexpression or knockdown experiments on cultured lens epithelial cells (LECs). In addition, the expression of DNA methyl transferase 1 (DNMT1) was higher in the lens epithelium of HMC patients than that of ARC patients, and the expression of GSTP1 and TXNRD2 was upregulated by use of a DNMT inhibitor in cultured LECs. Finally, we mimicked the intraocular environment of highly myopic eyes by treating LECs with hydrogen peroxide (H₂O₂) and observed both alterations in the methylation status of the GSTP1 and TXNRD2 promoters and time-dependent altered expression levels. Therefore, we propose that in an environment with high oxygen, in which lenses in highly myopic eyes are immersed, there exists a vicious cycle composed of increased oxidative stress and decreased enzymatic antioxidants via the hypermethylation of antioxidant genes.

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Vitreous liquefaction generates a high-O2 environment surrounding the lens.

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In highly myopic eyes, vitreous liquefaction occurs earlier and results in severer nuclear cataract.

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Methylation levels of GSTP1 and TXNRD2 were elevated in lens epithelium of highly myopic eyes.

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Increased oxidation and decreased enzymatic antioxidant via hypermethylation form a vicious circle in highly myopic eyes.

Optical Biometry-Based Intraocular Lens Calculation and Refractive Outcomes after Phacovitrectomy for Rhegmatogenous Retinal Detachment and Epiretinal Membrane

We investigate the refractive error after phacovitrectomy for rhegmatogenous retinal detachment (RRD; 100 eyes) and epiretinal membrane (ERM; 102 eyes). Axial lengths were measured by optical biometry in most patients. The main outcome measures were the refractive and absolute prediction errors. The overall mean refractive prediction error (ME) and mean absolute prediction error (MAE) were −0.40 ± 0.72 D and 0.62 ± 0.55 D, respectively, at 3 months postoperatively. The ME and MAE were significantly higher in the RRD group than in the ERM group (−0.63 ± 0.74 D vs −0.16 ± 0.63 D, P < 0.001 and 0.75 ± 0.62 D vs 0.49 ± 0.43 D, P = 0.002, respectively), indicating greater myopic shift in the RRD group. In the RRD group, adding +0.5 D to the preoperative predicted refractive power decreased the postoperative ME and MAE to −0.13 ± 0.74 D and 0.58 ± 0.47 D, respectively. Based on our results, we conclude that postoperative myopic shift was significantly higher in the RRD group than in the ERM group, possibly because of forward displacement of the intraocular lens by gas tamponade. The myopic shift can be minimized by adding +0.5 D to the predicted refractive power in patients undergoing phacovitrectomy for RRD.

Perfluorocarbon Liquid Vs. Subretinal Fluid Drainage during Vitrectomy for the Primary Repair of Rhegmatogenous Retinal Detachment: A Comparative Study

PURPOSE

To compare the anatomical and functional results achieved with subretinal fluid drainage (SRFD) and perfluorocarbon liquid (PFCL) use in patients with rhegmatogenous retinal detachment (RRD) treated by primary pars plana vitrectomy (PPV).

METHODS

The study included 162 eyes of 162 patients who underwent PPV for RRD, either with PFCL (n = 108) or SRFD (n = 54). The two groups were matched in 2:1 ratio for age, gender, and lens status. Groups were compared for rates of retinal reattachment, visual improvement, and the occurrence of recurrent RRD and any other postoperative complications.

RESULTS

Both groups had a single surgery success rate of 90.7%, and 100% of retinas were reattached by the end of follow-up. Both groups had similar final VA (0.30 ± 0.39 logMAR in the SRFD group and 0.35 ± 0.44 in the PFCL group; p = 0.48) and degrees of visual improvement (0.64 ± 0.75 logMAR in the SRFD group and 0.59 ± 0.89 in the PFC group; p = 0.71). Complication rates were also similar between groups. The rate of additional interventions was higher (although not statistically significant) in the PFCL group than the SRFD group, due to cases of PFCL retention (4.6% vs. 1.8%, respectively).

CONCLUSIONS

Both PFCL and SRFD achieved excellent results in terms of retinal reattachment and visual improvement, and have comparable safety profiles. A slightly higher rate of additional surgeries was found in the PFCL group. These findings indicate that PFCL are not necessary in routine PPV for RRD, as they do not improve the results achieved with SRFD and may be less cost-effective due to their higher price and potential for a higher rate of additional surgeries.

Visual outcome and complications of cataract extraction after pars plana vitrectomy

Purpose

To evaluate the visual outcomes and complications of phacoemulsification in previously vitrectomized eyes.

Patients and methods

A retrospective analysis of 87 consecutive vitrectomized eyes (87 patients) which had undergone phacoemulsification with intraocular lens implantation between 2013 and 2016.

Results

The mean interval from pars plana vitrectomy (PPV) to cataract surgery (CS) was 18.8 months. Mean age at CS was 61.5 years. Intraoperative complications included anterior rhexis tear (1 eye) and hyphema (1 eye). Postoperative complications included macular edema (17.2%, mean 42 days), posterior capsule opacification (13.8%, mean 14 months), ocular hypertension (11.5%), and anterior uveitis (1.1%). Preoperative mean best-corrected visual acuity improved from 20/50 to 20/25. Ninety-one percent of the eyes gained 2 or more lines, and 95% achieved visual acuity ≥20/40 after CS. Preoperative mean spherical equivalent improved from -4.35 to -0.17. Eyes with clear lens prior to the PPV had later CS (clear lens 27.1 vs no clear lens 9.7 months; p=0.016). Patients >55 years with clear lens at PPV (n=21) had earlier CS than younger ones with clear lens (n=24) (11.8 vs 40.5 months; p=0.033). Mean follow-up was 14.5 months.

Conclusion

Phacoemulsification is a safe procedure in vitrectomized eyes, with substantial gains in vision in most cases. Patients of advanced age and eyes without clear lens prior to the PPV had earlier CS.

Surgical Management of Idiopathic Macular Holes

Idiopathic macular holes have long been considered to be a stable, untreatable condition with little or no chance of spontaneous visual improvement. Within the last few years, surgical intervention has been developed for the management of idiopathic Stage 3 and Stage 4 holes. With pars plana vitrectomy surgery, at least 50% of patients will experience a 2 or more line improvement in visual acuity, and 25% of patients will improve to 20/40 or better. Since the natural history of idiopathic macular holes is extremely poor, all patients with Stage 3 or 4 lesions should be seriously considered for vitreous surgery.

Identification of H2O2 induced oxidative stress associated microRNAs in HLE-B3 cells and their clinical relevance to the progression of age-related nuclear cataract

BACKGROUND

This study is aimed to screen out the microRNAs (miRNAs) associated with H₂O₂ induced oxidative stress in human lens epithelial B3 (HLE-B3) cell lines and investigate their relations with the progression of age-related nuclear cataract.

METHODS

H₂O₂ was used to induce oxidative stress in HLE-B3 cells. A genome-wide expression profiling of miRNAs in HLE-B3 cells was performed to select the differentially expressed miRNAs before and after H₂O₂ treatment. The selected miRNAs were validated by RT-PCR and fluorescence in situ hybridization (FISH). Clinical specimens were divided into three groups according to the Lens Opacities Classification System III (LOCSIII) and the expression levels of the selected miRNAs were tested by RT-PCR in the three groups. Bioinformatics analyses were applied to predict the target genes of the miRNA hits and construct the miRNA regulatory network. The expression level of MAPK14 was analyzed by Western blot.

RESULTS

The H₂O₂ induced oxidative stress model of HLE-B3 cells was established. Nineteen upregulated and 30 downregulated miRNAs were identified as differentially expressed miRNAs. Seven of the total 49 were validated in the cell model. RT-PCR of the clinical samples showed that the expression levels of miR-34a-5p, miR-630 and miR-335-3p were closely related with the severity of nuclear opacity. The images taken from FISH confirmed the results of RT-PCR. There were 172 target genes of the three miRNAs clustered in the category of response to stress. The regulatory network demonstrated that 23 target genes were co-regulated by multiple miRNAs. MAPK14 was the target gene of three miRNAs and the result were verified by Western blot.

CONCLUSION

Up-regulation of miR-34a-5p and miR-630 and down-regulation of miR-335-3p are related with the progression of age-related nuclear cataract and the underlying mechanism awaits further functional research to reveal.

Surgery for postvitrectomy cataract

BACKGROUND

Cataract formation or acceleration can occur after intraocular surgery, especially following vitrectomy, a surgical technique for removing the vitreous that is used in the treatment of many disorders that affect the posterior segment of the eye. The underlying problem that led to vitrectomy may limit the benefit from removal of the cataractous lens.

OBJECTIVES

To evaluate the effectiveness and safety of surgery versus no surgery for postvitrectomy cataract with respect to visual acuity, quality of life, and other outcomes.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 5), MEDLINE Ovid (1946 to 17 May 2017), Embase.com (1947 to 17 May 2017), PubMed (1946 to 17 May 2017), Latin American and Caribbean Health Sciences Literature database (LILACS) (January 1982 to 17 May 2017), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com); last searched May 2013, ClinicalTrials.gov (www.clinicaltrials.gov); searched 17 May 2017, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en); searched 17 May 2017. We did not use any date or language restrictions in the electronic searches for trials.

SELECTION CRITERIA

We planned to include randomized controlled trials (RCTs) and quasi-RCTs that had compared surgery versus no surgery to remove the lens from eyes of adults in which cataracts had developed following vitrectomy.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the search results according to the standard methodological procedures expected by Cochrane.

MAIN RESULTS

We found no RCTs or quasi-RCTs that had compared surgery versus no surgery to remove the lens from eyes of adults in which cataracts had developed following vitrectomy.

AUTHORS' CONCLUSIONS

There is no evidence from RCTs or quasi-RCTs on which to base clinical recommendations for surgery for postvitrectomy cataract. There is a clear need for RCTs to address this evidence gap. Such trials should stratify participants by their age, the retinal disorder leading to vitrectomy, and the status of the underlying disease process in the contralateral eye. Outcomes assessed in such trials may include changes (both gains and losses) of visual acuity, quality of life, and adverse events such as posterior capsular rupture and retinal detachment. Both short-term (six-month) and long-term (one- or two-year) outcomes should be examined.

The quantitative assessment of alterations in lens transparency after transconjunctival 27-gauge microincision vitrectomy surgery

PurposeTo evaluate the baseline and post-vitrectomy lens densitometry values by a Scheimpflug camera in eyes with epiretinal membrane that were treated with 27-G microincision vitrectomy surgery (MIVS) without tamponade and to compare the results with those in fellow healthy eyes.Patients and methodsProspective case series. The lens densitometry measurements of 24 patients, who underwent 27-G MIVS without any tamponade for the treatment of epiretinal membrane, were taken preoperatively and on the first week, first month, and third month postoperatively with Pentacam HR-Scheimpflug imaging system.ResultsThe mean lens densitometry values at Zone 1 and average lens densitometry values significantly increased in the study eyes on the first month when compared with the preoperative values (P=0.011, P=0.033, respectively). Additionally, there were statistically significant differences regarding the mean lens densitometry values of Zone 1 and Zone 2, and also average lens densitometry values between the preoperative and third month postoperative values (P=0.003, P=0.021, P=0.009, respectively). However, the densitometry values of fellow eyes were similar at preoperatively and all the postoperative follow-up periods (P>0.05 for all).ConclusionsThis study suggests that 27-G MIVS might cause post-surgical lens density changes even in early postoperative months and vitreous may play an important role in protecting the transparency of the lens.

Effects of Vitrectomy and Lensectomy on Older Rhesus Macaques: Oxygen Distribution, Antioxidant Status, and Aqueous Humor Dynamics

Purpose

The purpose of this study is to evaluate effects of vitrectomy (PPV) and lens extraction with intraocular lens implantation (PE/IOL) on molecular oxygen (pO₂) distribution, aqueous humor antioxidant–oxidant balance, aqueous humor dynamics, and histopathologic changes in the trabecular meshwork (TM) in the older macaque monkey.

Methods

Six rhesus monkeys underwent PPV followed by PE/IOL. pO₂, outflow facility, and intraocular pressure (IOP) were measured. Aqueous and vitreous humor specimens were analyzed for antioxidant status and 8-hydroxy-2′-deoxyguanosine (8-OHdG), a marker of oxidative damage. TM specimens were obtained for immunohistochemical and quantitative PCR analysis.

Results

pO₂ at baseline revealed steep gradients in the anterior chamber and low levels in the posterior chamber (PC) and around the lens. Following PPV and PE/IOL, pO₂ significantly increased in the PC, around the IOL, and angle. IOP increased following both surgical interventions, with no change in outflow facility. Histopathologic analysis did not show changes in TM cell quantification, but there was an increase in 8-OHdG. Quantitative PCR did not reveal significant differences in glaucoma-related gene expression. Aqueous and vitreous humor analysis revealed decreased ascorbate and total reactive antioxidant potential and increased 8-OHdG in the aqueous humor only in the surgical eyes.

Conclusions

Oxygen distribution in the older rhesus monkey is similar to humans at baseline and following surgical interventions. Our findings of histopathologic changes of TM oxidative damage and alterations in the oxidant-antioxidant balance suggest a potential correlation of increased oxygen exposure with oxidative stress/damage and the development of open angle glaucoma.

Cataract Formation and Progression in Patients Less Than 50 Years of Age after Vitrectomy

PURPOSE

To measure the rate of cataract development and progression of nuclear sclerotic cataracts (NSC), posterior subcapsular cataracts (PSC), and cortical spoking cataracts in nondiabetic patients <50 years of age after a pars plana vitrectomy.

DESIGN

Retrospective cohort study.

SUBJECTS

Twenty-six eyes of 26 patients <50 years of age that had undergone a pars plana vitrectomy were included.

METHODS

Clinical records were reviewed retrospectively.

MAIN OUTCOME MEASURES

The NSC, PSC, and cortical spoking scores were recorded preoperatively and 1, 3, 6, 9, and 12 months after surgery until discharged from care, lost to follow-up, or last visit before cataract surgery. Eyes were graded on a scale of 0 to 4.0 using the lens opacities classification system LOCS II before and after pars plana vitrectomy for macular hole, epiretinal membranes, and vitreous hemorrhage. Linear regression analysis was performed to evaluate the rate of change in cataract score with elapsed time since surgery.

RESULTS

The mean age at surgery was 30.6±14.3 years in 26 eyes with a median follow-up of 12 months. Eleven of 26 surgical eyes (42.3%) that had a baseline NSC and PSC score of zero in their surgical eye developed NSC, PSC, or both after vitrectomy. The mean progression for NSC, PSC, and cortical spoking were 0.327±0.14 (P = 0.032), 0.414±0.14 (P = 0.008), and 0.00±0.00 over a mean follow-up of 1.43 years, respectively. Linear regression analysis shows minimal increase in NSC (+0.09/year; P < 0.001; R² = +0.331), a slight increase in PSC (+0.16/year; P < 0.001; R² = +0.835), and a minimal decrease in cortical spoking (-0.02/year; P < 0.05; R² = -0.09).

CONCLUSIONS

Our findings suggest there is a minimal but significant increase in NSC and PSC scores for patients <50 years after pars plana vitrectomy. Cataract progression is not a significant factor in the first few years after vitrectomy in patients <50 years of age.

Acute and late toxicity of bilateral orbital irradiation in the management of primary intraocular lymphoma

Primary intraocular lymphoma (PIOL) is a rare malignancy with poor outcomes. Concerns regarding toxicity lead some clinicians to exclude orbital radiation therapy (RT). We aimed to quantify the ocular toxicity of RT in 11 PIOL patients treated with chemoimmunotherapy and bilateral orbital RT (median 36 Gy). A multidisciplinary team, including an ocular oncologist, followed patients for a median of 42 months after RT. Common adverse events included dermatitis (100%), conjunctivitis (82%), xerophthalmia (64%), and keratopathy (45%). All phakic eyes developed cataracts (100%); correction resulted in good vision recovery. New, visually significant retinopathy was observed in only one eye (<5%) and affected a patient with preexisting diabetes. This report suggests that severe, vision-threatening complications following orbital RT are uncommon. In the absence of comorbidities, orbital RT should not be withheld due to fear of vision-threatening toxicity. The risk of toxicity may be augmented by comorbidities, so an individualized approach is recommended.

Comparative evaluation of outcomes of phacoemulsification in vitrectomized eyes: silicone oil versus air/gas group

The purpose of this study is to comparatively evaluate the morphology of cataract, intraoperative and postoperative complications (IPC), and surgical outcomes of phacoemulsification in post 23G vitrectomized eyes in silicone oil versus air/gas group. This prospective interventional clinical study took place in the Dr. RP Centre for Ophthalmic Sciences, AIIMS, New Delhi, India. Eighty-nine eyes of 89 consecutive vitrectomized patients with cataract were included. All underwent phacoemulsification and evaluated for cataract morphology, surgical difficulties, IPC, visual acuity, and specular count. Mean age of patients was 50.24 ± 15.19 years. There were 65 males and 24 females and 48 eyes in silicone oil group and 41 in air/gas group. Combination type was the commonest morphology seen in both silicone oil (52.08 %) and air/gas group (70.33 %) followed by posterior subcapsular cataract (PSC) in 31.25 % silicone group and 12.2 % air/gas group. Posterior capsular plaque (PCP) was seen in 41.67 % of silicone oil versus 7.32 % air/gas group; p < 0.005. Pupillary abnormalities were significantly more in oil (31.25 %) than in air/gas group (9.76 %); p = 0.014. Mean duration between vitrectomy and phacoemulsification in oil group versus air/gas group was 8.39 ± 4.7 months and 10.9 ± 5.22 months, respectively; p < 0.005. Mean postoperative logMAR visual acuity was better in air/gas (0.43 ± 0.25) than in oil (0.66 ± 0.29) group, p < 0.005. There was no significant difference in mean endothelial cell loss postoperatively in either groups (p = 0.25). Morphology of cataract differs in the two groups with PSC being more common in oil group. The mean time of cataract onset was significantly less in patients with oil group, and poor visual outcome in oil group may be attributable to the increased PCP noted.

Change in refraction after lens-sparing vitrectomy for rhegmatogenous retinal detachment and epiretinal membrane

The aim of this study was to compare changes in refraction following lens-sparing vitrectomy between patients with rhegmatogenous retinal detachment (RRD) and epiretinal membrane (ERM) and to investigate factors associated with the change in refraction.We reviewed medical records of 49 eyes of 49 patients with RRD (53.6 ± 7.8 years, mean ± standard deviation) and 24 eyes of 24 patients with ERM (50.9 ± 15.7 years) who underwent lens-sparing vitrectomy. Spherical equivalent refractive power was evaluated before and up to 18 months after surgery. The relationship between the change in refraction and several parameters was evaluated.A significant progressive myopic shift in refractive power was observed after vitrectomy in operated RRD and ERM eyes (P < 0.001, P = 0.016, respectively), with no significant difference in fellow eyes. The refraction values observed at ≥3 and ≥12 months following vitrectomy were significantly different as compared with those observed at baseline in the RRD group (P < 0.001) and the ERM group (P < 0.05), respectively. The change in refraction between the RRD and ERM groups was significant (P = 0.030). The multiple linear regression analysis showed that only age was significantly correlated with the change in refraction in RRD (P = 0.018) and ERM (P < 0.001) groups. The change in refraction was significantly and positively correlated with age in RRD (r = -0.461, P = 0.001) and ERM (r = -0.687, P < 0.001) groups. Following lens-sparing vitrectomy, cataract surgery was performed on 30 eyes after 0.89 ± 0.26 years in the RRD group and on 10 eyes after 1.11 ± 0.14 years in the ERM group; there was a significant difference in time to cataract surgery between the groups (P = 0.007). Kaplan-Meier survival analysis demonstrated that there was a significant difference in the rate of cataract surgeries between the RRD and ERM groups (P = 0.022).Following lens-sparing vitrectomy for RRD and ERM, a progressive myopic shift in refraction owing to nuclear sclerosis was observed. Core vitrectomy itself would cause a myopic shift of refraction. The only risk factor associated with cataract progression following lens-sparing vitrectomy is age for both types of patients.

25-Gauge Vitrectomy with Epiretinal Membrane and Internal Limiting Membrane Peeling in Eyes with Very Good Visual Acuity

PURPOSE

To evaluate the efficacy and safety of pars plana vitrectomy (PPV) in patients with epiretinal membrane (ERM) and preoperative visual acuity (VA) of 20/40 or better.

METHODS

44 eyes that underwent PPV and ERM peeling were included in this retrospective study. Data retrieved included demographic information, VA and intraocular pressure (IOP) preoperatively, after 1 month, 6 months and at final visit, presence of metamorphopsia, surgical reports, and occurrence of any complications.

RESULTS

Mean preoperative VA was 20/36 (0.24 ± 0.08 logMAR) and had improved to 20/27 (0.13 ± 0.11 logMAR) at the final follow-up (p < 0.001). Thirty (68.1%) eyes had improved by 1 line of vision or more, and 10 (22.7%) achieved final 20/20 vision. Significant improvement in vision was achieved earlier in eyes that underwent vitrectomy combined with cataract extraction. Preoperative OCT scans demonstrated preserved outer retinal layer structure.

CONCLUSIONS

PPV and ERM peeling is a safe and effective procedure in eyes with very good preoperative VA. PPV combined with cataract extraction offers a faster improvement in VA than PPV alone with deferred cataract surgery. PPV should be considered in symptomatic eyes with ERM and VA of 20/40 or better, in order to preserve and even improve the VA.

Longitudinal Study of Age-Related Cataract Using Dynamic Light Scattering: Loss of α-Crystallin Leads to Nuclear Cataract Development

PURPOSE

To conduct a longitudinal study on age-related nuclear cataracts using dynamic light scattering (DLS) to determine if cataract progression is associated with loss of the unbound form of the lens molecular chaperone protein, α-crystallin.

DESIGN

Natural history and cohort study.

PARTICIPANTS

Patients 30 years of age or older of either gender seeking treatment at the Wilmer Eye Institute Cornea-Cataract Department.

METHODS

All patients underwent a comprehensive dilated eye examination every 6 months, including slit-lamp grading of their lenses using the Age-Related Eye Disease Study (AREDS) clinical lens grading system and obtaining an estimate of unbound α-crystallin level in the nucleus, the α-crystallin index (ACI), using the National Aeronautics and Space Administration-National Eye Institute DLS device. We used a random effects statistical model to examine the relationship of lens opacity changes over time with ACI changes.

MAIN OUTCOME MEASURES

α-Crystallin Index (ACI) and AREDS nuclear cataract grade.

RESULTS

Forty-five patients (66 eyes) 34 to 79 years of age with AREDS nuclear lens grades of 0 to 3.0 were followed up every 6 months for a mean of 19 months (range, 6-36 months). We found that lenses with the lowest baseline levels of ACI had the most rapid progression of cataracts, whereas lenses with higher ACI at baseline had no or slower cataract progression. Lenses that lost α-crystallin at the highest rates during the study also had faster progression of nuclear cataracts than lenses with a slower rate of ACI loss. Kaplan-Meier survival curves showed that lenses with the lowest initial ACI had the highest risk of undergoing cataract surgery.

CONCLUSIONS

This longitudinal study corroborates our previous cross-sectional study finding that higher levels of unbound α-crystallin as assessed by ACI are associated with lower risk of cataract formation and that loss of ACI over time is associated with cataract formation and progression. This study suggested that assessment of ACI with the DLS device could be used as a surrogate for lens opacity risk in clinical studies, and for assessing nuclear cataract events in studies where cataract development may be a side effect of a drug or device.

Combined cataract extraction and vitrectomy for macula-sparing retinal detachment: visual outcomes and complications

Purpose

To evaluate the visual outcome of combined phacoemulsification, intraocular lens implantation, and vitrectomy for macula-sparing rhegmatogenous retinal detachment.

Methods

The results of combined vitrectomy with cataract extraction were retrospectively analyzed in patients with preexisting cataracts and new-onset rhegmatogenous retinal detachment. To qualify, patients must also have had macular sparing in a region 6,000 µm in diameter on optical coherence tomography. The anatomical success rate, visual outcomes, and postoperative complications relating to visual acuity were evaluated.

Results

In 56 patients followed postoperatively for more than 12 months, the initial and final surgical success rate was 96.4% and 100%, respectively. The mean preoperative logarithm of the minimum angle of resolution visual acuity was 0.05 and decreased to 0.11 postoperatively (p < 0.001). Of the 56 patients, 20 (35.7%) had worse visual acuity postoperatively, compared with preoperatively (0.06 vs. 0.27, p < 0.001); these cases were comprised of six patients with epiretinal membranes, 12 patients with a posterior capsule opacity, and two patients with cystoid macular edema. In the remaining 36 patients, there were no significant differences in visual acuity preoperatively and postoperatively (0.04 vs. 0.03, p = 0.324).

Conclusions

In patients with cataracts who develop macula-sparing rhegmatogenous retinal detachment and whose visual prognosis is excellent assuming the retina can be reattached successfully, combined phacoemulsification, intraocular lens implantation, and vitrectomy might be an effective treatment. However, the visual prognosis is significantly affected by postoperative complications such as an epiretinal membranes, posterior capsule opacity, and cystoid macular edema. Therefore, further studies should examine methods to prevent these postoperative complications.