Clinical and histological features of epiretinal membrane after diabetic vitrectomy

Impact of Aflibercept vs Dexamethasone Treatment on Epiretinal Membrane Formation in Eyes with Diabetic Macular Edema

INTRODUCTION

This study aimed to investigate the impact of aflibercept and dexamethasone (DEX) on the formation of epiretinal membrane (ERM) and their treatment outcomes in eyes with diabetic macular edema (DME).

METHODS

In this retrospective cohort study, medical records of 124 eyes from 429 patients diagnosed with DME were reviewed between June 2017 and June 2019. Patients were categorized into two groups: the aflibercept group (67 eyes) and the DEX group (57 eyes). The primary endpoint was the secondary ERM incidence following intravitreal treatments and its correlation across different medications. Secondary endpoints included longitudinal changes in best-corrected visual acuity (BCVA) and central macular thickness (CMT).

RESULTS

Over a 24-month follow-up, eyes treated with DEX had approximately a fourfold higher incidence of ERM development compared to aflibercept [hazard ratio (HR) = 3.97, p = 0.02]. These eyes also showed worse BCVA (p = 0.059) and increased CMT (p = 0.004), despite requiring fewer total injections (p = 0.000) in the survival analysis model. The cumulative probability of ERM formation was 13.7%. Additionally, DME eyes exhibited poor functional and anatomical outcomes after developing ERM, while age, A1c level, DR severity, initial BCVA and CMT, lens status, and previous laser treatment were not associated with an elevated incidence of ERM formation.

CONCLUSION

Intravitreal DEX implantation in DME eyes resulted in a higher incidence of secondary ERM formation compared to aflibercept over a 2-year period. The therapeutic efficacy for DME was diminished following ERM development, leading to worse anatomical outcomes. New therapeutic approaches should be explored to prevent ERM formation while maintaining both anatomical and functional outcomes in DME treatment.

Refining vitrectomy for proliferative diabetic retinopathy

Pars plana vitrectomy (PPV) is the main treatment modality for patients with severe diabetic retinopathy. With the development of systems for microincision, wide-angle viewing, digitally assisted visualization, and intraoperative optical coherence tomography, contemporary PPV for diabetic retinopathy has been performed on a wider range of indications than previously considered. In this article, we reviewed, in conjunction with our collective experiences with Asian patients, the applications of new technologies for PPV in eyes with diabetic retinopathy and highlighted several important procedures and entities not generally reiterated in the literature, in order for vitreoretinal surgeons to optimize their approaches when facing the challenges imposed by the complications in diabetic eyes.

Anti-vascular endothelial growth factors in combination with vitrectomy for complications of proliferative diabetic retinopathy

BACKGROUND

Vitrectomy is an established treatment for the complications of proliferative diabetic retinopathy (PDR). However, a number of complications can occur during and after vitrectomy for PDR. These include bleeding and the creation of retinal holes during surgery, and bleeding, retinal detachment and scar tissue on the retina after surgery. These complications can limit vision, require further surgery and delay recovery. The use of anti-vascular endothelial growth factor (anti-VEGF) agents injected into the eye before surgery has been proposed to reduce the occurrence of these complications. Anti-VEGF agents can reduce the amount and vascularity of abnormal new vessels associated with PDR, facilitating their dissection during surgery, reducing intra- and postoperative bleeding, and potentially improving outcomes.

OBJECTIVES

To assess the effects of perioperative anti-VEGF use on the outcomes of vitrectomy for the treatment of complications for proliferative diabetic retinopathy (PDR).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; which contains the Cochrane Eyes and Vision Trials Register; 2022, Issue 6); Ovid MEDLINE; Ovid Embase; the ISRCTN registry; ClinicalTrials.gov and the WHO ICTRP. The date of the search was 22 June 2022.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that looked at the use of anti-VEGFs and the incidence of complications in people undergoing vitrectomy for PDR.   DATA COLLECTION AND ANALYSIS: Two review authors independently assessed and extracted the data. We used the standard methodological procedures expected by Cochrane. The critical outcomes of the review were the mean difference in best corrected visual acuity (BCVA) between study arms at six (± three) months after the primary vitrectomy, the incidence of early postoperative vitreous cavity haemorrhage (POVCH, within four weeks postoperatively), the incidence of late POVCH (occurring more than four weeks postoperatively), the incidence of revision surgery for POVCH within six months, the incidence of revision surgery for recurrent traction/macular pucker of any type and/or rhegmatogenous retinal detachment within six months and vision-related quality of life (VRQOL) measures. Important outcomes included the proportion of people with a visual acuity of counting fingers (1.8 logMAR or worse), the number of operative retinal breaks reported and the frequency of silicone oil tamponade required at time of surgery.

MAIN RESULTS

The current review includes 28 RCTs that looked at the pre- or intraoperative use of intravitreal anti-VEGFs to improve the outcomes of pars plana vitrectomy for complications of PDR. The studies were conducted in a variety of countries (11 from China, three from Iran, two from Italy, two from Mexico and the remaining studies from South Korea, the UK, Egypt, Brazil, Japan, Canada, the USA, Indonesia and Pakistan). The inclusion criteria for entry into the studies were the well-recognised complications of proliferative retinopathy: non-clearing vitreous haemorrhage, tractional retinal detachment involving the macula or combined tractional rhegmatogenous detachment. The included studies randomised a total of 1914 eyes.  We identified methodological issues in all of the included studies. Risk of bias was highest for masking of participants and investigators, and a number of studies were unclear when describing randomisation methods and sequence allocation. Participants receiving intravitreal anti-VEGF in addition to pars plana vitrectomy achieved better BCVA at six months compared to people undergoing vitrectomy alone (mean difference (MD) -0.25 logMAR, 95% confidence interval (CI) -0.39 to -0.11; 13 studies, 699 eyes; low-certainty evidence). Pre- or intraoperative anti-VEGF reduced the incidence of early POVCH (12% versus 31%, risk ratio (RR) 0.44, 95% CI 0.34 to 0.58; 14 studies, 1038 eyes; moderate-certainty evidence). Perioperative anti-VEGF use was also associated with a reduction in the incidence of late POVCH (10% versus 23%, RR 0.47, 95% CI 0.30 to 0.74; 11 studies, 579 eyes; high-certainty evidence). The need for revision surgery for POVCH occurred less frequently in the anti-VEGF group compared with control, but the confidence intervals were wide and compatible with no effect (4% versus 13%, RR 0.44, 95% CI 0.15 to 1.28; 4 studies 207 eyes; moderate-certainty evidence). Similar imprecisely measured effects were seen for revision surgery for rhegmatogenous retinal detachment (5% versus 11%, RR 0.50, 95% CI 0.15 to 1.66; 4 studies, 145 eyes; low-certainty evidence).  Anti-VEGFs reduce the incidence of intraoperative retinal breaks (12% versus 31%, RR 0.37, 95% CI 0.24 to 0.59; 12 studies, 915 eyes; high-certainty evidence) and the need for silicone oil (19% versus 41%, RR 0.46, 95% CI 0.27 to 0.80; 10 studies, 591 eyes; very low-certainty evidence). No data were available on quality of life outcomes or the proportion of participants with visual acuity of counting fingers or worse.

AUTHORS' CONCLUSIONS

The perioperative use of anti-VEGF reduces the risk of late POVCH, probably results in lower early POVCH risk and may improve visual outcomes. It also reduces the incidence of intraoperative retinal breaks. The evidence is very uncertain about its effect on the need for silicone oil tamponade. The reported complications from its use appear to be low. Agreement on variables included and outcome standardisation is required in trials studying vitrectomy for PDR.

Inner limiting membrane peeling prevents secondary epiretinal membrane after vitrectomy for proliferative diabetic retinopathy

AIM

To evaluate the role of internal limiting membrane (ILM) peeling in preventing secondary epiretinal membrane (ERM) formation in pars plana vitrectomy (PPV) for proliferative diabetic retinopathy (PDR).

METHODS

This retrospective study analyzed the medical records of patients who underwent PPV for PDR and were followed up for minimum 3mo. ILM peeling was performed based on the intraoperative surgeons' judgments. ERM was assessed by optical coherence tomography photography. The relationship between ILM peeling and postoperative ERM was analyzed.

RESULTS

In total, 212 eyes from 197 patients were included in this study. The incidence of secondary ERM in the ILM non-peeling group was significantly higher than that in the ILM peeling group (37.0% vs 14.0%; P<0.001). Multivariate logistical regression revealed that ILM peeling was highly associated with the prevention of secondary ERM development [odds ratio 0.38; 95% confidence interval 0.17-0.86; P<0.05].

CONCLUSION

ILM peeling during PPV for PDRs can effectively reduce the incidence of secondary ERM development and is worth consideration by vitreoretinal surgeons.

Vitreomacular Interface Disorders in Proliferative Diabetic Retinopathy: An Optical Coherence Tomography Study

Vitreomacular interface plays an important role in the pathogenesis and progression of proliferative diabetic retinopathy (PDR). This study investigated the prevalence and risk factors of vitreomacular interface disorders (VMID) in PDR. The macular optical coherence tomography (OCT) scans of 493 eyes from 378 PDR patients were retrospectively reviewed to detect VMID, including vitreomacular adhesion (VMA), vitreomacular traction (VMT), epiretinal membrane (ERM), lamellar hole-associated epiretinal proliferation (LHEP), and macular hole (MH). The associations between VMID and baseline factors, intraretinal structure, and visual acuity were analyzed. The prevalence was 78.9% for ERM, 13.4% for VMT, 4.8% for MH, 2.2% for LHEP, and 2.0% for VMA, respectively. On multivariable analyses (odds ratio, 95% confidence interval), fibrovascular proliferation (FVP) was positively associated with MH (8.029, 1.873-34.420), VMT (3.774, 1.827-7.798), and ERM (2.305, 1.460-3.640). High-risk PDR was another risk factor of ERM (1.846, 1.101-3.090). Female gender was positively associated with MH (3.836, 1.132-13.006), while vitreous hemorrhage was negatively associated with MH (0.344, 0.133-0.890). Eyes with all VMID subtypes showed more frequent macular cysts and tractional retinal detachment with poorer visual acuity (p ≤ 0.001). Therefore, the prevalence of VMID was considerably high, indicating that this distinct entity should be considered in interventions for PDR.

Secondary Full-thickness Macular Holes after Diabetic Vitrectomy: Clinical Manifestations and Rational Approaches to the Treatment

Purpose. The aim of the study is to present the clinical characteristics and surgical treatment of secondary full-thickness macular hole (MH) after diabetic vitrectomy (DV) in patients with proliferative diabetic retinopathy (PDR). Methods. In this retrospective, observational, and longitudinal study, we enrolled consecutive patients with PDR who developed MH after DV. The macular structure was evaluated using optical coherence tomography. The clinical characteristics, surgical techniques, and outcomes were also recorded. Results. Three patients developed MH within 6 weeks, which was associated with foveal thinning, residual fibrovascular proliferation, or anterior proliferative vitreoretinopathy. Six patients developed MH originating from the epiretinal membrane (ERM) with lamellar MH (LMH) after a median interval of 16.5 months. Three of them were complicated with retinal detachment (RD). Various surgical procedures were performed according to the clinical scenarios, including internal limiting membrane (ILM) peeling, inverted ILM flap insertion, temporal inverted ILM flap, lens posterior capsular flap insertion, and neurosensory retinal free flap insertion. All patients achieved MH closure after surgery, and 5 patients exhibited improved visual acuity. Conclusions. MH may develop after successful DV, with a high rate of associated RD. Rapid MH formation was attributed to unreleased tractional force and weakened foveal structure. The development of ERM and LMH also led to MH. Various surgical techniques could be used for MH closure.

PARS PLANA VITRECTOMY WITH and WITHOUT ILM-PEELING for DIABETIC PATIENTS with MACULA INVOLVED TRACTIONAL RETINAL DETACHMENT

PURPOSE

To evaluate the effect of internal limiting membrane (ILM) peeling on anatomical and functional results in pars plana vitrectomy (PPV) performed eyes with tractional retinal detachment affecting the macula due to diabetes mellitus (DM).

METHODS

Patients without ILM peeling were considered as Group 1, and with ILM peeling were considered as Group 2. The main outcomes were the best-corrected visual acuity (BCVA) at 6 months, and the rate of epiretinal membrane (ERM) formation within 6 months. The rate and the indications for resurgery were determined. Parameters affecting final BCVA were determined by regression analysis.

RESULTS

Final BCVA was significantly better in eyes with ILM-peeled off than in eyes with no peel-off (p=0.012). Less secondary ERM was formed in Group 1 (p=0.009). There was no difference between groups in terms of resurgery rates. (p=0.143). The need for resurgery due to ERM was higher in Group 1 rather than Group 2 (p=0.001). The only factor affecting final BCVA was ILM peeling.

CONCLUSION

In patients with tractional retinal detachment affecting the macula due to diabetes, ILM peeling in addition to PPV and membrane excision does not affect the need for resurgery but contributes positively to anatomical and functional outcomes.

Secondary epiretinal membrane after Ex-Press glaucoma filtration device implant

Purpose

To estimate the frequency of epiretinal membrane (ERM) in eyes with primary open-angle glaucoma (POAG) treated with Ex-Press shunt implant. Secondarily, we aimed to assess the role of concomitant cataract surgery and the impact of the ERM on central foveal thickness and macular volume.

Methods

In this prospective, consecutive, case-control study, we enrolled 54 patients affected by PAOG and scheduled for Ex-Press device implant with or without contemporary phacoemulsification. Contralateral eyes affected by POAG and receiving anti-glaucomatous eyedrops constituted the control group. Complete ophthalmologic evaluation and spectral-domain optical coherence tomography (OCT) were performed before and 1, 3 and 6 months after surgery.

Results

Twenty-six eyes received the Ex-Press implant alone, and 28 eyes underwent the combined procedure. Six months postoperatively, we observed 18 (33%) cases of ERM: 15 (28%) of cellophane macular reflex (CMR) and 3 (6%) of pre-macular fibrosis (PMF). In the control group, 9 (17%) eyes developed an ERM: 8 (15%) were CMR, and 1 (2%) was PMF. The frequency of ERM statistically differs between treated and contralateral eyes (P = 0.032, χ² test). The ERM frequency did not statically differ between eyes subjected to simple or combined surgery (P = 0.846, χ² test). Mean central foveal thickness and mean macular volume did not significantly differ between groups.

Conclusion

The Ex-Press glaucoma shunt may increase the risk of ERM onset regardless of the concomitant cataract surgery; however, most cases were cellophane macular reflex with limited functional and anatomical impact.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00417-020-05025-8.

The Effect of Internal Limiting Membrane Cleaning on Epiretinal Membrane Formation after Vitrectomy for Proliferative Diabetic Retinopathy

PURPOSE

We hypothesised that cleaning the internal limiting membrane (ILM) with a flexible nitinol loop following diabetic vitrectomy without peeling may reduce the common occurrence of postoperative epiretinal membrane (ERM) formation.

METHODS

Consecutive patients undergoing vitrectomy for proliferative diabetic retinopathy by one surgeon from 2015 to 2019 were studied and divided into 2 cohorts: the control group underwent standard surgery, and the ILM clean group underwent additional cleaning of the macular retina using a flexible nitinol loop after vitrectomy. Masked comparison of ERM on optical coherence tomography was performed at 3 months, and visual acuity (VA) was measured until 12 months postoperatively.

RESULTS

Baseline demographics, clinical features, and protein levels were similar between cohorts. The ILM clean group (n = 56) had fewer clinically significant ERM than the control group (n = 50; 4 vs. 20%; p = 0.01), and a significantly lower proportion of the ILM clean group required revision surgery (2 vs. 14%; p = 0.02). VA in the ILM clean group was significantly better than in the control group at 3 months (0.35 vs. 0.50 logMAR; p = 0.02) but not at 12 months (0.34 vs. 0.43 logMAR; p = 0.17).

CONCLUSION

ILM cleaning with a flexible nitinol loop following diabetic vitrectomy resulted in significant reduction in ERM formation and reduced necessity for revision surgery. There was significant improvement in VA at 3 months but not over a longer follow-up.

Increased Expression of Growth Hormone-Releasing Hormone in Fibrinous Inflammation of Proliferative Diabetic Retinopathy

PURPOSE

To investigate the involvement of growth hormone-releasing hormone (GHRH) - growth hormone (GH) signaling in pathogenesis of proliferative diabetic retinopathy (PDR).

DESIGN

Experimental laboratory study.

METHODS

Vitreous humor, aqueous humor, and serum were obtained from 36 eyes of 36 patients with or without type 2 diabetes from 2017 to 2019. For histologic examination, 6 fibrovascular membranes were excised from eyes with active PDR. Three fibrovascular membranes were excised from nondiabetic patients with proliferative vitreoretinopathy (PVR) as controls.

RESULTS

In PDR, the fibrovascular tissues consisted of a mature region containing fibrocytes, and an immature region populated by abundant polymorphonuclear leukocytes in a fibrinogen meshwork. Clusters of leukocytes were found adhering to the vascular walls. In PVR, no fibrinogen and polymorphonuclear leukocyte was observed in the fibrovascular membranes. The levels of GHRH and GH in PDR were significantly increased (P < .001), with 1.8-fold and 72.8-fold in vitreous humor, and 2-fold and 4.9-fold in aqueous humor, respectively, when compared with corresponding levels in controls. No significant difference was detected for insulin-like growth factor-1. Immunohistochemistry showed intense expression of GHRH and its receptor GHRH-R in polymorphonuclear leukocytes, vascular endothelial cells, and fibrocytes in fibrovascular membranes of PDR. GHRH staining was not detectable in infiltrating cells within the fibrovascular membrane of PVR.

CONCLUSIONS

These findings reveal a possible involvement of GHRH/GHRH-R in fibrinous inflammation that might contribute to the formation of fibrovascular membrane in PDR through mediating activities of leukocytes, vascular endothelial cells, and fibrocytes. Targeting GHRH/GHRH-R may be considered as a potential therapeutic approach for the treatment of PDR.

Current management of diabetic tractional retinal detachments

Twenty-five percent of diabetes-related vision loss stems from complications of proliferative diabetic retinopathy (PDR). Panretinal photocoagulation has been the preferred treatment of high-risk PDR for decades and more recently intravitreal injections of drugs that inhibit the actions of vascular endothelial growth factor have become popular. But despite these treatments PDR may progress uncontrollably to advanced pathologies such as traction retinal detachments (TRDs), combined traction/rhegmatogenous retinal detachments (TRD/RRDs), vitreous hemorrhages, rubeosis iridis, and traction maculopathies, which produce mild-to-severe loss of vision. TDR have long been the most common indication for PDR-related vitreoretinal surgery. Vitrectomy surgery is indicated for recent (<6 months duration) TRD involving the macula, progressive TRD that threatens the macula, and recent data suggest that chronic macula-involving TRDs (>6 months duration) may also benefit. Combined TRD/RRD represents a particularly challenging surgical condition but advances in surgical instrumentation, dissection techniques, and post-operative tamponade have produced excellent success rates. The recent development of small-gauge vitrectomy systems has persuaded most surgeons to switch platforms since these appear to produce shorter surgical times and quicker post-operative recoveries. Pre-operative injections of bevacizumab are frequently administered for persistent neovascularization to facilitate surgical dissection of pre-retinal fibrosis and reduce the incidence of post-operative hemorrhages. Recent trends toward earlier surgical intervention and expanded indications are likely to continue as surgical instrumentation and techniques are further developed.

PECULIARITIES OF VITRECTOMY AND MORPHOLOGIC CHANGES IN THE EPIRETINAL MEMBRANE AFTER INTRAVITREAL AFLIBERCEPT IN PATIENTS WITH SEVERE PROLIFERATIVE DIABETIC RETINOPATHY

PURPOSE

To examine the peculiarities of vitrectomy and morphologic changes in the epiretinal membrane after intravitreal aflibercept in patients with proliferative diabetic retinopathy.

METHODS

Prospective study of 21 consecutive cases with proliferative diabetic retinopathy complicated by vascularized epiretinal membrane forming tractional retinal detachment that underwent pars plana vitrectomy 4 days after intravitreal injection of aflibercept. After removal, the epiretinal membranes were taken for histologic examination using light microscopy. Obliteration of neovascularization of epiretinal membranes, the lack of bleeding in the intraoperative and early postoperative periods, retinal attachment, and improvement of visual acuity were taken for the criteria of treatment effectiveness.

RESULTS

On the fourth day after intravitreal injection, newly formed vessels of epiretinal membranes were completely obliterated. There was no bleeding during segmentation and delamination of epiretinal membranes during vitrectomy. In the early postoperative period, bleeding complications were not noted. A microscopic examination of epiretinal membranes showed single-thin-walled capillary vessels lined with endothelial cells, the lumen of which does not contain blood cells. Capillaries are submerged in the connective tissue of different degrees of maturity.

CONCLUSION

Intravitreal aflibercept resulted in the obliteration of neovascularization of epiretinal membranes, thus avoiding intraoperative and postoperative bleeding during vitrectomy. The improvement in visual acuity was noted in all cases. Histologic examination of epiretinal membranes determined single-thin-walled capillary vessels lined with endothelial cells without blood cells.

Segmentation and removal of fibrovascular membranes with high-speed 23 G transconjunctival sutureless vitrectomy, in severe proliferative diabetic retinopathy

Aim

To evaluate the effectiveness and safety of high-speed (5,000 cuts per minute) 23 G transconjunctival sutureless vitrectomy (TSV) in severe diabetic fibrovascular proliferation (DFVP).

Patients and methods

In this retrospective consecutive case series, patients who underwent 23 G TSV for severe DFVP between October 2011 and March 2014 at our institution were evaluated. 23 G TSV was performed with a high-speed (5,000 cuts per minute) cutter without a chandelier light.

Results

The mean follow-up period was 8 months (range: 4–23 months). Of the 27 eyes of 27 patients, 14 eyes (52%) underwent concomitant phacoemulsification with posterior chamber intraocular lens implantation, nine eyes (33%) were pseudophakic, and four eyes were phakic (15%). DFVP was removed with ease in all, and visual acuity was improved in 18 (67%) eyes. Iatrogenic retinal tear was observed in four eyes (15%) and treated successfully during surgery. Suture placement to a single sclerotomy was performed in eight eyes (30%). Postoperative intraocular hemorrhage was observed in five eyes (18%). Cataract formation was observed in two of the four phakic eyes. Three (11%) patients had postoperative intraocular pressure rise. Postoperative hypotony (≤6 mmHg) and endophthalmitis were not observed in any eye.

Conclusion

The segmentation and removal of fibrovascular membranes with high-speed 23 G TSV seems to be a safe and easy method in severe diabetic eye disease.

Surgical treatment for diabetic vitreoretinal diseases: a review

Over the past four decades, advancements in surgical instrumentations and techniques have significantly improved the postoperative anatomical and visual outcomes of patients with various diabetic vitreoretinal diseases. In particular, surgical interventions for previously serious and untreatable blinding proliferative diabetic retinopathy can now be performed, with much better results. The advents of micro incisional vitrectomy system with better visualization system like binocular indirect ophthalmomicroscope and state-of-the-art instrumentation revolutionized the era of diabetic vitrectomy. High-speed vitrectors, finer instruments, chromo-assisted vitrectomy and use of anti-vascular endothelial growth factors not only change the paradigm but also help achieve much better outcome after diabetic vitrectomies. In this review, we will discuss and summarize the indications, surgical considerations, surgical techniques, potential complications and outcomes of vitreoretinal surgery for diabetic eye diseases.

Epiretinal membrane: optical coherence tomography-based diagnosis and classification

Epiretinal membrane (ERM) is a disorder of the vitreomacular interface characterized by symptoms of decreased visual acuity and metamorphopsia. The diagnosis and classification of ERM has traditionally been based on clinical examination findings. However, modern optical coherence tomography (OCT) has proven to be more sensitive than clinical examination for the diagnosis of ERM. Furthermore, OCT-derived findings, such as central foveal thickness and inner segment ellipsoid band integrity, have shown clinical relevance in the setting of ERM. To date, no OCT-based ERM classification scheme has been widely accepted for use in clinical practice and investigation. Herein, we review the pathogenesis, diagnosis, and classification of ERMs and propose an OCT-based ERM classification system.