Andrea Govetto

A Systematic Review of Endophthalmitis after Microincisional versus 20-Gauge Vitrectomy

BACKGROUND Endophthalmitis is a rare but severe complication of vitrectomy. CLINICAL RELEVANCE Post-surgical endophthalmitis is suspected to be more frequent after microincisional (23- and 25-gauge) compared with standard (20-gauge) vitrectomy. METHODS We conducted a systematic review of studies that compared microincisional and standard vitrectomy by searching MEDLINE and EMBASE up to November 2012. We used the Bayesian meta-analysis method to compute the odds ratio (OR) of endophthalmitis. We conducted subgroup analyses to compare the effect of different incision types and use of perioperative antibiotics. RESULTS We identified 3 small randomized and 18 nonrandomized studies that reported 68 cases of endophthalmitis in 148 643 participants. The overall OR of endophthalmitis for microincisional versus standard vitrectomy was 2.3 (95% credible interval [CrI], 0.8-5.8). We found an increased risk of endophthalmitis using a microincisional straight approach compared with standard vitrectomy (OR, 15.1; 95% CrI, 2.01-179), but not for a beveled approach (OR, 0.82; 95% CrI, 0.23-2.28). The OR of studies that reported on mixed microincision was between these 2 values (OR, 4.4; 95% CrI, 1.32-14.3). We estimated that the overall rate of endophthalmitis with 20-gauge vitrectomy was 3 cases in 10 000 procedures, and the probability that a beveled microincision increases the rate of endophthalmitis to more than 6 or 9 events was small (no more than 5% or 1%, respectively). CONCLUSIONS We did not find an increased risk of endophthalmitis for microincisional vitrectomy compared with standard vitrectomy. The beveled approach seems to be safer than a straight approach, supporting the current recommendation of its adoption in microincisional vitrectomy. However, these findings must be interpreted cautiously because of the small number of endophthalmitis events reported from included studies.

Insights Into Epiretinal Membranes: Presence of Ectopic Inner Foveal Layers and a New Optical Coherence Tomography Staging Scheme

PURPOSE To describe the presence of continuous ectopic inner foveal layers associated with epiretinal membranes (ERMs) and to present a new optical coherence tomography (OCT) staging system of ERMs. DESIGN Retrospective multicenter observational case series. METHODS Clinical charts and spectral-domain OCT images of 194 eyes of 172 consecutive patients diagnosed with ERMs were reviewed and analyzed. RESULTS The presence of continuous ectopic inner foveal layers was identified in 63 out of 194 eyes (32.5%) and this morphology was significantly associated with lower visual acuity. ERMs were divided into 4 stages. Stage 1 (43 out of 194 eyes, 22.1%) ERMs were mild and thin and a foveal depression was present. Stage 2 (88 out of 194 eyes, 45.4%) ERMs were associated with widening of the outer nuclear layer and loss of the foveal depression. Stage 3 (51 out of 194 eyes, 26.3%) ERMs were associated with continuous ectopic inner foveal layers crossing the entire foveal area. In stages 1, 2, and 3 all retinal layers were clearly defined on OCT. Stage 4 ERMs (12 out of 194 eyes, 6.2%) were thick and associated with continuous ectopic inner foveal layers. In addition, retinal layers were disrupted. Visual acuity progressively declined from stage 1 through stage 4 (P < .001). CONCLUSIONS The presence of continuous ectopic inner foveal layers in ERMs is a newly described OCT finding associated with significant vision loss and is an essential element of a novel OCT-based grading scheme of ERMs that may influence visual prognosis.

Prevalence of open angle glaucoma in vitrectomized eyes: a cross-sectional study.

Purpose: Primarily to assess and compare the prevalence of open-angle glaucoma (OAG) in previously vitrectomized and nonvitrectomized eyes at our institution. Secondarily to assess and compare the prevalence of OAG in eyes those were phakic and pseudophakic/aphakic at the time of vitrectomy. Methods: A cross-sectional prevalence study was designed. Patients who underwent pars plana vitrectomy at our institution from January 2006 to December 2011 and had not been diagnosed with OAG before the surgical procedure were contacted by phone. Those patients who agreed to participate were invited to the University Hospital of Ourense (Spain) for a comprehensive ophthalmic assessment, including Perkins tonometry, gonioscopy, examination of the optic disk, and a spectral-domain optical coherence tomography scan of the optic nerve head. The definition of OAG was based on standardized criteria, modified versions of the Rotterdam Study, and those published by Foster et al. Results: Among 472 eligible patients, 182 responded and agreed to participate in our study. Of these, 26 were excluded. Finally, 312 eyes of 156 patients were included in the analysis. Fifteen vitrectomized (8.9%) and 3 nonvitrectomized (2%) eyes were diagnosed with OAG. This difference was statistically significant (P = 0.02, chi-square test). Differences in the prevalence of OAG between eyes those were phakic and pseudophakic/aphakic at the time of vitrectomy were not statistically significant (P = 0.48, chi-square test). Conclusion: Our study supports the hypothesis of an increased risk of OAG after vitrectomy. Prevalence of OAG in vitrectomized eyes was significantly higher compared with nonvitrectomized ones. However, we were not able to demonstrate significant difference in the prevalence of OAG between eyes those were phakic or aphakic/pseudophakic at the time of vitrectomy.

LONG-TERM OUTCOMES OF 23-GAUGE PARS PLANA VITRECTOMY WITH INTERNAL LIMITING MEMBRANE PEELING AND GAS TAMPONADE FOR MYOPIC TRACTION MACULOPATHY: A Prospective Study.

Purpose: To investigate the long-term safety and efficacy of microincisional 23-gauge pars plana vitrectomy with internal limiting membrane (ILM) peeling and gas tamponade in the treatment of myopic traction maculopathy. Methods: A prospective nonrandomized multicenter study was designed. Patients with myopic traction maculopathy without macular hole and retinal detachment were included in the study between January 2009 and May 2012. All patients underwent microincisional 23-gauge pars plana vitrectomy with ILM peeling and 12% C3F8 gas tamponade. In all cases, brilliant blue G staining of the ILM was performed. All patients were prospectively evaluated. The evolution of best-corrected visual acuity (BCVA) and macular thickness were recorded. Results: Myopic traction maculopathy resolved in 28 of the 30 patients (93%) included. Mean follow-up was 33.8 ± 13 months (range, 24–60 months). Mean time of myopic traction maculopathy resolution after surgery was 2.65 ± 1.4 months. At 1 month after surgery, one patient developed a macular hole and another one a rhegmatogenous retinal detachment. After 2 years, another patient developed a retinal detachment. Statistically significant improvements in macular thickness compared with baseline were found at all follow-up visits (P < 0.001, Students t-test). At final visit, BCVA improved significantly compared with baseline (P = 0.044, Wilcoxons test). However, a statistically significant improvement in visual acuity was achieved only in eyes with a preoperative Snellen visual acuity ≥20/63 (P = 0.027). In contrast, the final BCVA of eyes with worse preoperative visual acuity (<20/63) did not improve significantly (P = 0.41, Wilcoxons test). Conclusion: Microincisional 23-gauge pars plana vitrectomy with ILM peeling and gas tamponade is effective in the treatment of myopic traction maculopathy, with low postoperative complications. Globally, both BCVA and macular thickness improved significantly during the follow-up period. However, greater visual acuity improvements were only seen in eyes with preoperative BCVA equal to or better than 20/63 Snellen equivalent. Some concerns remain about the risk of macular hole formation after ILM peeling. Further studies are necessary to investigate this issue.

Frequency of pseudoexfoliation among patients scheduled for cataract surgery.

Purpose To assess the frequency of pseudoexfoliation syndrome (PXF) in patients scheduled for cataract surgery and to evaluate its association with pupil dilation, lens nucleus hardness, intraocular pressure (IOP), glaucoma, age, and sex. Setting Ourense University Hospital, Ourense, Spain. Design Cross‐sectional study. Methods This study evaluated eyes scheduled for cataract surgery between January 2013 and July 2013. Pseudoexfoliation was diagnosed in phakic eyes that showed central and/or peripheral white deposits on the lens surface, pupillary margin, or both. Dilated pupils were evaluated with a portable pupil chart. Nucleus hardness was assessed according to the Lens Opacities Classification System III. Diagnosis of glaucoma was based on International Society Geographical and Epidemiological Ophthalmology criteria. Results Of the 1763 eyes (1093 patients) evaluated, 381 (21.6%) were diagnosed with PXF. The frequency of PXF increased with age from 6.0% in people between 50 year and 60 years to 31.66% in those older than 80 years. In PXF eyes, nuclear cataracts were significantly harder than in non‐PXF eyes (P < .001). The mean IOP was significantly higher in PXF eyes than in non‐PXF eyes (P = .002). The frequency of glaucoma was higher in PXF eyes (17.4%) than in non‐PXF eyes (9.4%), with a statistically significant difference (P < .001). In PXF eyes, the pupil was significantly smaller than in non‐PXF eyes (P < .001). Conclusions The frequency of PXF was high in the study population and increased with age. Eyes with PXF were associated with significantly harder nuclear cataracts, smaller pupils, and glaucoma. Financial Disclosure No author has a financial or proprietary interest in any material or method mentioned.

Choroidal thickness in non-neovascular versus neovascular age-related macular degeneration: a fellow eye comparative study

Purpose To investigate the possible differences in choroidal thickness (CT) between non-neovascular (NNV) and neovascular (NV) age-related macular degeneration (AMD). Methods A retrospective, observational chart review of consecutive patients diagnosed with NNV AMD in one eye and with NV AMD in the fellow eye was carried out. NNV AMD was classified into four subgroups according to the Beckman Initiative for Macular Research AMD Classification Committee Meeting. CT was manually assessed using enhanced depth imaging optical coherence tomography from 1500 µm nasal to 1500 µm temporal to the fovea. Parametric and non-parametric tests were used to compare quantitative variables, a χ2 test was used to compare categorical variables and logistic regression was used to evaluate associations of CT with other variables of interest. Results In this study, 322 eyes from 161 patients were included and 102 (63.35%) were female and 59 (36.65%) were male, with a mean age of 80.80±8.45 years (range 58–99 years). Mean follow-up was 11.2±10.8 months (range 1–38 months). In NNV AMD eyes, the choroid was significantly thicker in the subfoveal and temporal regions of the macula, if compared with NV AMD fellow eyes. Differences in CT between NNV AMD and NV AMD fellow eyes were higher at earlier stages of NNV AMD. Conclusions Subfoveal and temporal choroid was significantly thicker in NNV AMD compared with NV AMD fellow eyes. There was a significant choroidal thinning at advanced stages of NNV AMD.

Short-term results of platelet-rich plasma as adjuvant to 23-G vitrectomy in the treatment of high myopic macular holes.

Purpose To investigate the short-term safety and efficacy of autologous platelet-rich plasma (a-PRP) as adjuvant to pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling in the treatment of highly myopic macular holes (MH). Methods This was a prospective, nonrandomized interventional case series. Patients with MH associated with high myopia, with or without previous PPV, were included. All patients underwent 23-G PPV with the use of a-PRP. Anatomical and functional results of surgery were recorded. Results We included 7 eyes of 6 patients with highly myopic MH. Primary anatomical success was achieved in 7 out of 7 eyes. Mean best-corrected visual acuity improved by more than 1 line from baseline (0.66 ± 0.36 LogMAR) to final visit (0.52 ± 0.25 logMAR), but with no statistically significant difference (p = 0.246, Wilcoxon test). No surgical-related complications were noticed. Conclusions The use of a-PRP as adjuvant to PPV with ILM peeling is effective in the treatment of highly myopic MH. This approach may represent a valid alternative to the inverted ILM flap technique, with comparable visual and anatomical results and the advantage of a simpler procedure. Further studies are necessary to confirm its usefulness in the management of high myopic MH.

Bilateral and Simultaneous Central Retinal Vein Occlusion in a Patient with Obstructive Sleep Apnea Syndrome

Purpose: To describe a case of bilateral and simultaneous central retinal vein occlusion (RVO) in a young patient diagnosed with obstructive sleep apnea syndrome (OSAS). Case Report: A 38-year-old man with morbid obesity and daytime sleepiness presented with a history of bilateral vision loss. His visual acuity (VA) was hand movements, and fundus examination (FE) revealed bilateral central RVO. General medical examination revealed untreated hypertension and type II respiratory failure. Laboratory tests for thrombophilia showed increased hematocrit (59%) and high levels of fibrinogen and C-reactive protein. Other causes of congenital and acquired hypercoagulability were ruled out. Pathologic polysomnography led to the diagnosis of OSAS. The patient was treated with antihypertensive drugs and continuous positive air pressure. In addition, he received intravitreal ranibizumab. At 10 months after presentation, his VA was no light perception in the right eye and hand movements in the left eye. FE revealed bilateral retinal and optic nerve atrophy, and the occurrence of a nonarteritic anterior ischemic neuropathy in the right eye was considered.

OCULAR HYPERTENSION AND GLAUCOMA FOLLOWING VITRECTOMY: A Systematic Review

Purpose: Pars plana vitrectomy has been reported to increase the risk of ocular hypertension and open-angle glaucoma. The authors conducted a systematic review of randomized and nonrandomized studies to compare the incidence of open-angle glaucoma and ocular hypertension in vitrectomized versus nonvitrectomized eyes. Methods: A literature search was performed using MEDLINE and EMBASE until August 2016. Data on ocular hypertension and open-angle glaucoma incidence and mean intraocular pressure after at least 1 year were pooled using random-effects metaanalysis models. Because only nonrandomized studies were retrieved, ROBINS-I tool was used to assess risk of bias in the review. Results: Seven included studies had a paired design to compare the outcomes of vitrectomized versus fellow eyes, with mean follow-up of least 12 months. Four studies (851 patients) provided data on open-angle glaucoma: incidence in vitrectomized versus non-vitrectomized eyes was 7.8% and 4.8%, respectively, yielding a metaanalytic odds ratio of 1.67 (95% CI: 1.08–2.57). Six studies (1,060 patients) reported on the occurrence of ocular hypertension, which was 5.8% in vitrectomized eyes versus 3.1% in fellow eyes (odds ratio: 2.03, 95% CI: 0.97–4.22), without significant differences in the mean postoperative intraocular pressure (mean difference 0.31 mmHg, 95% CI: −0.26 to 0.89). Conclusion: Although the review found increased risk of open-angle glaucoma with pars plana vitrectomy, the studies were heterogenous or inconsistent regarding ocular hypertension and intraocular pressure increase. Larger studies should be conducted in homogenous cohorts of patients undergoing macular surgery, excluding complex conditions such as retinal detachment or diabetic retinopathy.

Feasibility of a polyethylene glycol-derived polymer as retinal patch to seal retinal breaks during vitrectomy for rhegmatogenous retinal detachment: a prospective, in vivo pilot study in a porcine model

This is a pilot study to test a polyethylene glycol‐derived polymer used as a retinal patch to seal retinal breaks during pars plana vitrectomy in the treatment of rhegmatogenous retinal detachment in a porcine model.