ILM peeling a vital intervention for many vitreoretinal disorders

Pars plana vitrectomy with internal limiting membrane flap versus pars plana vitrectomy with conventional internal limiting membrane peeling for large macular hole

BACKGROUND

Macular hole (MH) is a full-thickness defect in the central portion of the retina that causes loss of central vision. According to the usual definition, a large MH has a diameter greater than 400 µm at the narrowest point. For closure of MH, there is evidence that pars plana vitrectomy (PPV) with internal limiting membrane (ILM) peeling achieves better anatomical outcomes than standard PPV. PPV with ILM peeling is currently the standard of care for MH management; however, the failure rate of this technique is higher for large MHs than for smaller MHs. Some studies have shown that the inverted ILM flap technique is superior to conventional ILM peeling for the management of large MHs.

OBJECTIVES

To evaluate the clinical effectiveness and safety of pars plana vitrectomy with the inverted internal limiting membrane flap technique versus pars plana vitrectomy with conventional internal limiting membrane peeling for treating large macular holes, including idiopathic, traumatic, and myopic macular holes.

SEARCH METHODS

The Cochrane Eyes and Vision Information Specialist searched CENTRAL, MEDLINE, Embase, two other databases, and two trials registries on 12 December 2022.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that evaluated PPV with ILM peeling versus PPV with inverted ILM flap for treatment of large MHs (with a basal diameter greater than 400 µm at the narrowest point measured by optical coherence tomography) of any type (idiopathic, traumatic, or myopic).

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane and assessed the certainty of the body of evidence using GRADE.

MAIN RESULTS

We included four RCTs (285 eyes of 275 participants; range per study 24 to 91 eyes). Most participants were women (63%), and of older age (range of means 59.4 to 66 years). Three RCTs were single-center trials, and the same surgeon performed all surgeries in two RCTs (the third single-center RCT did not report the number of surgeons). One RCT was a multicenter trial (three sites), and four surgeons performed all surgeries. Two RCTs took place in India, one in Poland, and one in Mexico. Maximum follow-up ranged from three months (2 RCTs) to 12 months (1 RCT). No RCTs reported conflicts of interest or disclosed financial support. All four RCTs enrolled people with large idiopathic MHs and compared conventional PPV with ILM peeling versus PPV with inverted ILM flap techniques. Variations in technique across the four RCTs were minimal. There was some heterogeneity in interventions: in two RCTs, all participants underwent combined cataract-PPV surgery, whereas in one RCT, some participants underwent cataract surgery after PPV (the fourth RCT did not mention cataract surgery). The critical outcomes for this review were mean best-corrected visual acuity (BCVA) and MH closure rates. All four RCTs provided data for meta-analyses of both critical outcomes. We assessed the risk of bias for both outcomes using the Cochrane risk of bias tool (RoB 2); there were some concerns for risk of bias associated with lack of masking of outcome assessors and selective reporting of outcomes in all RCTs. All RCTs reported postoperative BCVA values; only one RCT reported the change in BCVA from baseline. Based on evidence from the four RCTs, it is unclear if the inverted ILM flap technique compared with ILM peeling reduces (improves) postoperative BCVA measured on a logarithm of the minimum angle of resolution (logMAR) chart at one month (mean difference [MD] -0.08 logMAR, 95% confidence interval [CI] -0.20 to 0.05; P = 0.23, I2 = 65%; 4 studies, 254 eyes; very low-certainty evidence), but it may improve BCVA at three months or more (MD -0.17 logMAR, 95% CI -0.23 to -0.10; P < 0.001, I2 = 0%; 4 studies, 276 eyes; low-certainty evidence). PPV with an inverted ILM flap compared to PPV with ILM peeling probably increases the proportion of eyes achieving MH closure (risk ratio [RR] 1.10, 95% CI 1.02 to 1.18; P = 0.01, I2 = 0%; 4 studies, 276 eyes; moderate-certainty evidence) and type 1 MH closure (RR 1.31, 95% CI 1.03 to 1.66; P = 0.03, I² = 69%; 4 studies, 276 eyes; moderate-certainty evidence). One study reported that none of the 38 participants experienced postoperative retinal detachment.

AUTHORS' CONCLUSIONS

We found low-certainty evidence from four small RCTs that PPV with the inverted ILM flap technique is superior to PPV with ILM peeling with respect to BCVA gains at three or more months after surgery. We also found moderate-certainty evidence that the inverted ILM flap technique achieves more overall and type 1 MH closures. There is a need for high-quality multicenter RCTs to ascertain whether the inverted ILM flap technique is superior to ILM peeling with regard to anatomical and functional outcomes. Investigators should use the standard logMAR charts when measuring BCVA to facilitate comparison across trials.

Long-term assessment of internal limiting membrane peeling for full-thickness macular hole using en face adaptive optics and conventional optical coherence tomography

OBJECTIVE

To evaluate the long-term structural and microvascular retinal effects of internal limiting membrane peeling for full-thickness macular hole (FTMH) using en face adaptive optics optical coherence tomography (AO-OCT), conventional OCT, and OCT angiography (OCTA).

DESIGN

Interventional case series.

PARTICIPANTS

Patients with FTMH treated with vitrectomy, internal limiting membrane peeling, and gas tamponade.

METHODS

Eleven eyes with FTMH that had at least 12 months of postoperative follow-up were enrolled in the study. En face AO-OCT was used to image the superficial retina in the peeled and nonpeeled areas. En face structural OCT was performed to image the inner retinal dimples (IRDs), macular thickness, and retinal nerve fibre layer (RNFL). En face OCTA was used to examine the integrity of the peripapillary nerve fibre layer (NFL) plexus.

RESULTS

AO-OCT showed RFNL wrapping around the IRDs, and no obvious peripapillary NFL plexus dropout was seen with OCTA. Scattered hyper-reflective dots were observed on the surface of the peeled retina in all patients imaged with AO-OCT. No significant differences were found in IRD number (91.5 ± 24.4 versus 77.2 ± 14.7; P = 2.07), IRD proportionate area (8.36 ± 3.34 versus 7.53 ± 2.60; P = 0.159), or macular thickness between the 6- and 12-month (or greater) postoperative visits.

CONCLUSION

IRDs do not to progress beyond 6 months postoperatively, and no obvious damage to RFNL and peripapillary NFL plexus was detected. Hyper-reflective dots on the surface of the retina suggestive of possible Müller cell reactive gliosis were identified with AO-OCT.

A Comparison of Peel-Induced Maculopathy Following ILM Peeling Using a Microvacuum Pick Versus Forceps

OBJECTIVE

To compare peel-induced maculopathy (PIM) using surgical forceps versus the microvacuum pick (MVP).

METHODS

Consecutive eyes undergoing internal limiting membrane (ILM) peeling using either the MVP or forceps were assessed. En face optical coherence tomography (OCT) images at the level of the nerve fiber layer were generated for 6-month postoperative visit. The percentage of the imaged area showing PIM was termed the PIM index. PIM severity was additionally measured using a qualitative PIM severity scale.

RESULTS

Seventy-four consecutive eyes underwent ILM peeling with either the MVP (36/74; 49%) or forceps (38/74; 51%). At month-6 postoperatively, the mean PIM index for forceps was 7.7% vs 4.7% for the MVP (P < 0.001, R² = 0.15). At 6 months, 26/38 eyes (68.5%) in the forceps group had either moderate or severe PIM compared to 12/36 eyes (33.3%) in the MVP group (P = 0.001).

CONCLUSIONS

ILM peeling with the MVP resulted in lower PIM severity compared to forceps. [Ophthalmic Surg Lasers Imaging Retina 2023;54:37-42.].

Vital dyes in macular hole surgery

Currently, surgical techniques, such as internal limiting membrane peeling, are used widely for macular holes, macular puckers, epiretinal membranes, diabetic macular edema, retinal detachment, retinal vein occlusions, vitreomacular traction, optic pit maculopathy, and Terson syndrome. This study aimed to highlight any differences regarding visual acuity and ocular tomography coherence changes after staining the internal limiting membrane with dilutions of Brilliant Blue G vs. lutein/zeaxanthin-based dyes. This study involved 30 eyes of 30 patients who had undergone posterior pole vitrectomy for idiopathic stage 4 macular hole. The study lot was divided in two subgroups, 15 eyes colored with Brilliant Blue and the other 15 eyes colored with lutein and zeaxanthin dyes. The association between visual prognosis, ocular tomography coherence changes and intraocular pressure was analyzed. The surgical treatment with required endoillumination levels and a 2-min period of dye using the Alcon Constellation Vision System had no negative impact on cell viability and improved visual acuity by 30%. Staining makes it easier to remove, to be quick and precise while performing macular surgeries. In has been observed that lutein and zeaxanthin dyes offer an intraoperative protective screen that protects photoreceptors more than Brilliant Blue while performing pars plana vitrectomy. Both study groups had good results in time. Surgical visualization is an evolving technology.

FACTORS ASSOCIATED WITH DEVELOPMENT OF DISSOCIATED OPTIC NERVE FIBER LAYER APPEARANCE IN THE PIONEER INTRAOPERATIVE OPTICAL COHERENCE TOMOGRAPHY STUDY

PURPOSE

To assess the relationship of dissociated optic nerve fiber layer (DONFL) and intraoperative membrane-peeling dynamics as visualized using intraoperative optical coherence tomography (OCT), and to evaluate the functional implications of DONFL.

METHODS

This was a post hoc analysis of eyes undergoing membrane peeling for vitreomacular interface disorders in the prospective PIONEER intraoperative OCT study. Retinal layer measurements in preincision and postpeel intraoperative OCT images were obtained. The primary outcome was development of DONFL appearance on spectral domain OCT at 6-month follow-up. Secondary outcomes included correlation of DONFL with surgical technique, surgical indication, intraoperative OCT findings, and retinal sensitivity.

RESULTS

Ninety-five eyes were included. The prevalence of DONFL at 6 months was 36%. Increased inner retinal layer thickness on intraoperative OCT immediately after membrane peeling was associated with development of DONFL (P < 0.01). Macular hole repair was significantly associated with DONFL appearance. Peel technique (forceps vs. diamond-dusted membrane scraper) was not associated with DONFL. There was no difference in retinal sensitivity or visual acuity between eyes with or without DONFL.

CONCLUSION

Acute postpeel increase in inner retinal thickness and macular hole repair were associated with development of DONFL appearance. However, it is unclear whether the surgical indication (e.g., macular hole) or the surgical manipulations performed (e.g., internal limiting membrane peeling) is the major factor that has an impact on DONFL appearance. Overall, these findings suggest that one mechanism in the development of DONFL appearance may be intraoperative trauma to the inner retina, potentially during internal limiting membrane peeling (e.g., macular hole repair).

Comparison of Visual Outcome and Morphologic Change between Different Surgical Techniques in Idiopathic Epiretinal Membrane Surgery

Purpose

To investigate the morphological and functional outcomes of idiopathic epiretinal membrane (ERM) surgery between three different surgical techniques: ERM peeling only, whole-piece ILM peeling, and maculorrhexis ILM peeling.

Patients and Methods

This is a retrospective, consecutive, and comparative study enrolling 60 patients from Kaohsiung Medical University Hospital, Kaohsiung, Taiwan. Surgery performed between July 2011 and June 2012 was done with ERM peeling only (group I). ERM peeling and ILM peeling as a whole piece (group II) were performed between July 2012 and July 2013. Surgery performed between August 2013 and December 2014 was done with maculorrhexis ILM peeling (group III). Main outcome measures include visual acuity change (BCVA) and central foveal thickness (CFT).

Results

At 12 months postoperation, the mean BCVA in group III was significantly better than in group I and group II. Comparison of CFT reduction between the three groups revealed significantly more reduction in group III than in group II at all postoperative follow-up periods. Eyes with restoration of foveal depression were observed in 52.6% in group I, 52.4% in group III, but only 20% of eyes in group II. None of the eyes in both ILM peeling groups encountered recurrence of macular pucker formation.

Conclusion

All three techniques can achieve visual acuity improvement and macular thickness reduction. Maculorrhexis ILM peeling achieves more rapid improvement of visual function, better final visual outcome, and a higher rate of normal foveal contour than whole-piece ILM peeling.

LONG-TERM RETROSPECTIVE ANALYSIS OF VISUAL ACUITY AND OPTICAL COHERENCE TOPOGRAPHIC CHANGES AFTER SINGLE VERSUS DOUBLE PEELING DURING VITRECTOMY FOR MACULAR EPIRETINAL MEMBRANES

PURPOSE

To determine the long-term effect of internal limiting membrane with associated epiretinal membrane (ERM) peeling versus single peeling alone in terms of best-corrected visual acuity and anatomical outcomes on spectral-domain optical coherence tomography.

METHODS

This retrospective comparative cohort study of patients who had follow-up of >1 year and underwent surgery for ERM by a single surgeon (S.C.) from January 1, 2008 to December 31, 2012 compared cases in which the internal limiting membrane was stained with brilliant blue G to facilitate double peeling (n = 42) and single peeling (n = 43) of the ERM alone for up to 3 years of follow-up. For continuous variables, an independent two-tailed t-test was performed. For binary variables, the Fisher's exact test was performed. Statistical significance was defined as P < 0.05.

RESULTS

Eighty-five of 142 patients fit the inclusion criteria. At the last follow-up, the single-peeling group were more likely to have ERM remaining in the central fovea postoperatively (P = 0.0020, becoming significant by postoperative Year 1, P = 0.022) and less likely to develop inner retinal dimpling (P = 0.000, becoming significant by postoperative Month 3, P = 0.015). At 3 years, central foveal thickness had decreased in the single-peeling group by -136.9 µm and by -84.1 μm in the double-peeling group, which was not significantly different (P = 0.08). Mean best-corrected visual acuity improved in both the groups at all time points. There was no statistically significant difference between the 2 groups at 3 years (P = 0.44; single-peeling group, 0.32 ± 0.42, Snellen 20/42; double-peeling group, 0.23 ± 0.27, Snellen 20/34).

CONCLUSION

Brilliant blue G-assisted internal limiting membrane peeling for ERM results in a more thorough removal of residual ERM around the paracentral fovea. However, there is no difference in long-term best-corrected visual acuity at 3 years and a greater likelihood of inner retinal dimpling.

Complications of Macular Peeling

Macular peeling refers to the surgical technique for the removal of preretinal tissue or the internal limiting membrane (ILM) in the macula for several retinal disorders, ranging from epiretinal membranes (primary or secondary to diabetic retinopathy, retinal detachment…) to full-thickness macular holes, macular edema, foveal retinoschisis, and others. The technique has evolved in the last two decades, and the different instrumentations and adjuncts have progressively advanced turning into a safer, easier, and more useful tool for the vitreoretinal surgeon. Here, we describe the main milestones of macular peeling, drawing attention to its associated complications.

Retinal Damage Induced by Internal Limiting Membrane Removal

The internal limiting membrane (ILM), the basement membrane of the Müller cells, serves as the interface between the vitreous body and the retinal nerve fiber layer. It has a fundamental role in the development, structure, and function of the retina, although it also is a pathologic component in the various vitreoretinal disorders, most notably in macular holes. It was not until understanding of the evolution of idiopathic macular holes and the advent of idiopathic macular hole surgery that the idea of adjuvant ILM peeling in the treatment of tractional maculopathies was explored. Today intentional ILM peeling is a commonly applied surgical technique among vitreoretinal surgeons as it has been found to increase the rate of successful macular hole closure and improve surgical outcomes in other vitreoretinal diseases. Though ILM peeling has refined surgery for tractional maculopathies, like all surgical procedures it is not immune to perioperative risk. The essential role of the ILM to the integrity of the retina and risk of trauma to retinal tissue spurs suspicion with regard to its routine removal. Several authors have investigated the retinal damage induced by ILM peeling and these complications have been manifested across many different diagnostic studies.