Microperimetric evaluation and predictive factors of visual recovery after successful inverted internal limiting membrane-flap technique for macular hole in high myopic eyes

Abstract

Introduction: Inverted Internal Limiting Membrane (ILM)-flap technique demonstrated its effectiveness, in terms of anatomical closure rate and visual acuity recovery for high myopic macular holes. We evaluated macular function after a successful inverted ILM-flap for macular holes in high myopic eyes (hMMH) using microperimetry to predict visual prognosis.

Methods: A retrospective study on 23 eyes of 23 patients after surgical closure of hMMH, was performed. All patients underwent inverted ILM-flap and gas tamponade. Cataract surgery was performed in phakic eyes. Study outcomes including best-corrected visual acuity (BCVA), retinal sensitivity (RS) at central 12°, central retinal sensitivity (CRS) at central 4° and mean deviation (MD), and fixation behavior as bivariate contour ellipse area (BCEA, degrees2) measured by microperimetry, were evaluated over 6 months. A mixed-effects model was used to evaluate and compare the repeated measurements of outcomes between phakic and pseudophakic eyes. A regression model was performed to assess the relationship between BCVA at 6 months and independent variables.

Results: Overall mean BCVA improved from 0.98 ± 0.21 logMAR at baseline to 0.47 ± 0.31 logMAR at the last follow-up (p < 0.001). Over 6 months, overall sensitivity measurements improved (RS, p = 0.001; CRS, p < 0.0001; MD, p = 0.03), and the BCEA decreased in dimension, although not significantly (p ≥ 0.05). The mixed model revealed a significantly better effect of inverted ILM-flap combined with cataract surgery on BCVA and CRS in phakic eyes than inverted ILM-flap alone in pseudophakic ones. The regression model revealed a relationship of 6-month BCVA with pre-operative BCVA (β = 0.60, p = 0.02) and RS (β = -0.03, p = 0.01).

Conclusion: The inverted ILM-flap technique significantly improved visual acuity and retinal sensitivity after the hMMH closure, particularly when combined with cataract extraction. Pre-operative visual acuity and retinal sensitivity at central 12° may predict post-surgical visual acuity.

Keywords: axial length; fixation behavior; high myopia; inverted ILM-flap; macular hole; microperimetry; retinal sensitivity.

Figure 1

Best corrected visual acuity (BCVA) changes over follow-up.

Figure 2

Retinal sensitivity (RS), central retinal sensitivity (CRS) and mean deviation (MD) changes over follow-up.

Figure 3

Bivariate contour ellipse area (BCEA) 68.2%, BCEA 95.4% and BCEA 99.6%BCEA changes over follow-up.

Figure 4

Microperimetric MP1 macular sensitivity interpolate maps at baseline and 6 months after surgery in some representative cases. Case 1. (Top Left) At baseline, microperimetry revealed an absolute scotoma (low values in retinal sensitivity; orange/red) within the central 4 degrees (central 13 points) surrounded by a relative ring scotoma (low-medium values in retinal sensitivity; yellow/orange). (Top Right) After 6 months from surgery, both overall and central sensitivity showed improvement despite low central values. The last BCEA showed a mild enlargement when compared to baseline. However, the majority of the fixation points (blue dots) are still clustered within the central degrees. Case 2. (Bottom Left) Results from the microperimetry test indicate a slight improvement in overall sensitivity from the initial test to the most recent follow-up. Notably, there was a marked improvement in the central scotoma. However, at the paracentral degrees, while some loci showed an increase in sensitivity, many others showed a decrease. The analysis of the BCEA revealed a narrowing of the fixation point cloud, predominantly in the outer ellipses at the last follow-up.

Figure 5

Line fit plot of baseline best corrected visual acuity (BCVA) and retinal sensitivity (RS) as predictive factors of 6-months BCVA.