A novel quantitative analysis method for idiopathic epiretinal membrane

RETINAL TECTONICS AFTER MACULAR PUCKER SURGERY: Thickness Changes and En Face Displacement Recovery

PURPOSE

To study visual function, retinal layer thickness changes, and tangential displacement after pars plana vitrectomy for epiretinal membrane.

METHODS

Retrospective series of patients undergoing pars plana vitrectomy for epiretinal membrane, with 6-month follow-up including best-corrected visual acuity, optical coherence tomography, M-charts, epiretinal membrane grading, and infrared fundus photograph at time 0 (T0, preop) at months 1 (T1), 3 (T3), and 6 (T6) postop (±1 week). Retinal layer thickness and tangential ( en face ) retinal displacement between successive times for the entire retinal surface and the central horizontal and vertical meridian were also measured. En face displacement was calculated as optical flow of consecutive images.

RESULTS

Average best-corrected visual acuity improved from 0.28 ± 0.08 logarithm of Minimum Angle of Resolution at T0 to 0.16 ± 0.25 at T6 ( P = 0.05), best-corrected visual acuity improvement correlated with best corrected visual acuity (BCVA) at T0 ( P < 0.001). Vertical metamorphopsia decreased from 1.33° ± 0.70° at T0 to 0.82° ± 0.69° at T6 ( P < 0.05). Foveal thickness reduced from 453 ± 53 µ m at T0 to 359 ± 31 µ m at T6 ( P < 0.05) and reduction correlated with best-corrected visual acuity improvement ( P < 0.05). Foveal layers decreased ( P < 0.05) in all cases. The mean en face deformation was 155.82 ± 50.17 µ m and mostly occurred in the first month: T0-T1 displacement was 83.59 ± 30.28 µ m, T1-T3 was 36.28 ± 14.45 µ m, while T3-T6 was 39.11 ± 22.79 µ m ( P < 0.001) on average. Perifoveal and parafoveal deformation correlated with optical coherence tomography foveal thickness reduction at all time intervals (1, 3, and 6 months: P < 0.01).

CONCLUSION

Epiretinal membrane peeling affects all retinal layer thickness and results in new force balance across the entire retina and tangential displacement. Both en face and in-depth changes correlate with visual function.

Total and horizontal distances of the foveal stereotaxic displacement can be prognostic indicators for patients with idiopathic epiretinal membrane

Introduction

This study aimed to examine the foveal stereo deviations in the different ectopic inner foveal layer (EIFL) stages of idiopathic epiretinal membrane (iERM) and assess its predictive utility for the baseline and postoperative best-corrected visual acuity (BCVA).

Methods

Based on the calculational combination of foveal displacements in the horizontal and vertical axial optical coherence tomography (OCT) images, the foveal stereotaxic displacement was estimated through the total distance (TD, the distance from the foveal bottom to the inner edge of displaced central foveal) and horizontal distance (HD, projection of the TD in the retinal plane). The preoperative TD, HD, and other OCT- and OCT angiography (OCTA)-related indicators were obtained. The correlations between structural parameters and baseline and postoperative BCVA were evaluated through correlation and multiple linear regression analyses.

Results

In patients with advanced EIFL stage, there was a significant increase in the HD, TD, baseline log of the minimum angle of resolution unit for BCVA, central macular thickness (CMT), acircularity index, and incidence of microcystic macular edema (MME; p &lt; 0.05). Further, they showed a decreased foveal avascular zone (FAZ) area and perimeter (p &lt; 0.001). HD, TD, CMT, MME, FAZ area, and FAZ perimeter were significantly correlated with the baseline and postoperative BCVA (p &lt; 0.05). TD had the highest correlation indexic and was an individual predictor of the baseline and postoperative BCVA. Moreover, FD-300 and MME were individual predictors of postoperative BCVA.

Discussion

Stereoscopic foveal deviations significantly correlated with the baseline and postoperative visual acuity. TD may be used as an independent prognostic factor for BCVA.

Associated factors and surgical outcomes of microcystoid macular edema and cone bouquet abnormalities in eyes with epiretinal membrane

PURPOSE

To investigate the associated features and the surgical outcomes in eyes with microcystoid macular edema (MME) and cone bouquet abnormalities (CBA) undergoing epiretinal membrane (ERM) peeling.

METHODS

Retrospective study including patients who underwent pars-plana vitrectomy for idiopathic ERM. Factors associated with MME and CBA at baseline and their regression were identified with logistic regression models. Postoperative visual acuity was evaluated with linear mixed models from baseline to 12 months. Risk factors for new or worsened macular edema (ME) were explored with a Cox regression model.

RESULTS

187 eyes were included; 30 eyes (16%) had MME; 53 eyes (28%) had CBA preoperatively. MME was associated with severe ERM stage (odds ratio (OR) [95% confidence interval (CI)] = 3.6[1.3-12.7], p=0.02); CBA inversely correlated with ectopic inner foveal layer thickness (OR [95% CI] = 0.97[0.97-0.99] for each 1-μm EIFL increase, p=0.006). Eyes with MME had worse visual acuity after ERM peeling (p=0.01) and were at risk of ME worsening (hazard ratio [95% CI] = 2.22[1.01-5.16], p=0.04). Older age was associated with MME persistence (OR [95%CI] = 2.46[1.06-6.82] for each 10-year increase, p=0.04). No significant associations were found for CBA.

CONCLUSION

While CBA had no prognostic consequences, MME was associated with suboptimal visual recovery and less efficient control of inflammation after surgery. Degeneration of Müller cells may have an alleged role, and further imaging and functional tests are warranted.