The Postoperative Course of Choroidal and Central Retinal Thickness in Epiretinal Membranes with Respect to Membrane Severity

Analysing early changes of photoreceptor layer thickness following surgery in eyes with epiretinal membranes

BACKGROUND/OBJECTIVES

To analyse short-term changes of mean photoreceptor thickness (PRT) on the ETDRS-grid after vitrectomy and membrane peeling in patients with epiretinal membrane (ERM).

SUBJECTS/METHODS

Forty-eight patients with idiopathic ERM were included in this prospective study. Study examinations comprised best-corrected visual acuity (BCVA) and optical coherence tomography (OCT) before surgery, 1 week (W1), 1 month (M1) and 3 months (M3) after surgery. Mean PRT was assessed using an automated algorithm and correlated with BCVA and central retinal thickness (CRT).

RESULTS

Regarding PRT changes of the study eye in comparison to baseline values, a significant decrease at W1 in the 1 mm, 3 mm and 6 mm area (all p-values < 0.001), at M1 (p = 0.009) and M3 (p = 0.019) in the central 1 mm area, a significant increase at M3 in the 6 mm area (p < 0.001), but no significant change at M1 in the 3 mm and 6 mm area and M3 in the 3 mm area (all p-values > 0.05) were observed. BCVA increased significantly from baseline to M3 (0.3LogMAR-0.15LogMAR, Snellen equivalent = 20/40-20/28 respectively; p < 0.001). There was no correlation between baseline PRT and BCVA at any visit after surgery, nor between PRT and BCVA at any visit (all p-values > 0.05). Decrease in PRT in the 1 mm (p < 0.001), 3 mm (p = 0.013) and 6 mm (p = 0.034) area after one week correlated with the increase in CRT (449.9 µm-462.2 µm).

CONCLUSIONS

Although the photoreceptor layer is morphologically affected by ERMs and after their surgical removal, it is not correlated to BCVA. Thus, patients with photoreceptor layer alterations due to ERM may still benefit from surgery and achieve good functional rehabilitation thereafter.

Surgical management, use and efficacy of adjuvant dyes in idiopathic epiretinal membranes: a systemic review with network meta-analysis

BACKGROUND

The epiretinal membrane (ERM) is a nonvascular fibrocellular tissue formed by cellular metaplasia and proliferation at the vitreoretinal surface and is generally treated by pars plana vitrectomy (PPV) with or without internal limiting membrane (ILM) peeling. This network meta-analysis aimed to compare the efficacy of all available ERM removal interventions and assessed the use and efficacy of surgical dyes in managing idiopathic ERMs.

METHODS

MEDLINE, EMBASE, Cochrane CENTRAL, and the US National Library of Medicine were searched (June 28, 2023). Clinical studies that included patients with ERMs were included. Randomized controlled trials (RCTs) were also appraised using Cochrane risk of bias (ROB).

RESULTS

Ten RCTs and ten non-RCTs were included in this study. A pairwise meta-analysis between ERM removal and combined ERM and ILM removal showed no significant difference in visual outcome (change in BCVA) 1 year postintervention (MD = - 0.0034, SE = 0.16, p = 0.832). Similarly, there was no significant difference in the central macular thickness postoperatively between the two groups (MD = - 4.95, SE = 11.11, p = 0.656) (Q = 4.85, df = 3, p = 0.182, I2 = 41.21%). The difference in ERM recurrence between the groups was also not statistically significant (OR = 4.64, p = 0.062, I2 = 0). In a network meta-analysis, there was no significant difference in visual outcomes between ERM removal only and other treatment modalities: combined ILM and ERM removal (MD = 0.039, p = 0.837) or watchful waiting (MD = 0.020, p = 0.550). In a network meta-analysis, there was no significant difference in the visual outcomes between ERM removal alone and dye-stained combined ERM and ILM peeling (MD = 0.122, p = 0.742 for brilliant blue G; BBG and MD = 0.00, p = 1.00 for membrane blue-dual; MBD). The probability of being a better surgical dye for better visual outcomes was 0.539 for the MBD group and 0.396 for the BBG group. The recurrence of ERM was not significantly different when the ILM was stained with any of the dyes. No study was judged on ROB assessment as having low ROB in all seven domains.

CONCLUSION

The two types of surgical modalities provided comparable efficacy, with no significant differences between the outcomes. Among the dye-assisted ILM peeling methods, the membrane blue-dual dye was the most effective in providing better structural and functional outcomes.

Choroidal morphologic and vascular features in patients with unilateral idiopathic epiretinal membranes: An optical coherence tomography analysis integrated with assessment of retinal layers

Introduction

Integrated analysis of retinal and choroidal morphologic and vascular features is urgently needed to examine whether and how these two elements interact with each other, thus contributing to visual impairment in patients with idiopathic epiretinal membranes (iERMs).

Methods

An observational retrospective study consisting of 181 patients diagnosed with unilateral iERM between August 2019 and July 2022 was carried out at Peking University Third Hospital. All patients underwent a standardized set of ophthalmologic examinations, including EDI-OCT and OCTA scanning, and were subsequently categorized into four stages according to current classification schemes based on their OCT findings. Altogether, 15 qualitative and quantitative parameters of both the retina (full-layer, inner and outer layers) and choroid were identified.

Results

The results revealed variations in the choroidal vascularity index (CVI) among different stages of iERMs (p < 0.001) for the first time. Distributions of retinal parameters across four stages of iERMs were validated. Correlation analysis between choroidal and retinal parameters showed that the CVI was associated with both inner and outer retinal morphologic biomarkers. Functional damage to retinal integrity was determined to be a strong contributor to visual acuity reduction in iERMs.

Discussion

This study complemented our present understanding of posterior segment structural and vascular alterations in iERMs.