Outer Plexiform Layer Angle: A Prognostic Factor for Idiopathic Macular Pucker Surgery

Abstract

Purpose. To investigate the efficacy of idiopathic macular pucker (epimacular membrane) surgery and to identify the possible prognostic factor. Methods. This was a retrospective study which enrolled 38 patients with idiopathic macular pucker who underwent 23-gauge pars plana vitrectomy (PPV) with indocyanine green-assisted peeling of epiretinal membrane (ERM) and internal limiting membrane (ILM). Visual outcomes were assessed at the baseline and during the follow-up including best-corrected visual acuity (BCVA) and metamorphopsia score, as well as outer plexiform layer (OPL) angle and central retinal thickness (CRT) using spectral-domain optical coherence tomography (SD-OCT). A comparison was made between patients with the prepeeling CRTs ≥500 μm and those <500 μm. A comparison was also made between patients with the prepeeling OPL angles ≥130° and those <130°. Based on the prepeeling parameters, the correlations between various prepeeling and postpeeling visual functions were analyzed. Results. Mean follow-up was 36.07 ± 4.62 months (range 1.30–96.70 months). BCVA was significantly improved from 0.26 ± 0.03 to 0.67 ± 0.04 p < 0.001 ; metamorphopsia score was significantly reduced from 1.42 ± 0.16 to 0.61 ± 0.08 p < 0.001 ; CRT was significantly decreased from 519.62 ± 13.41 μm to 385.37 ± 8.97 μm p < 0.001 . Greater prepeeling OPL angle (≥130°) was associated with significantly greater BCVA improvement (Snellen E/LogMAR: p = 0.01 / 0.03 ) and greater metamorphopsia reduction p = 0.03 , as compared to smaller OPL angle (<130°) with less BCVA improvement and less metamorphopsia reduction. However, the final BCVA improvement and metamorphopsia reduction relevant to the prepeeling smaller CRT (<500 μm) did not significantly differ from that relevant to the prepeeling greater CRT (≥500 μm; p > 0.05 ). Endophthalmitis, retinal tear, or retinal detachment was not observed after peeling. Conclusion. Indocyanine green-assisted ERM/ILM peeling combined with small gauge vitrectomy is associated with significant visual acuity improvement and metamorphopsia reduction in patients with idiopathic macular pucker. Greater prepeeling OPL angle rather than CRT might act as a useful prognostic factor in predicting better final visual functional outcomes.

Prediction of Visual Impairment in Epiretinal Membrane and Feature Analysis: A Deep Learning Approach Using Optical Coherence Tomography

“…ONL inward projection has been reported to be associated with the disappearance of the foveal pit and more significant retinal changes. 11,41 However, the disruption of the ELM and ellipsoid zone was seldom labeled as hot spots in the heat maps. In the parafoveal region, the inner retinal changes also played a more crucial role in causing visual impairment than the outer retinal changes.…”

“…ONL inward projection, presented in one-third of the images, was the most common outer retinal change at the fovea. ONL inward projection has been reported to be associated with the disappearance of the foveal pit and more significant retinal changes 11,41. However, the disruption of the ELM and ellipsoid zone was seldom labeled as hot spots in the heat maps.…”

“…40 Heat maps from 270 OCT images with profound visual impairment were examined for the OCT features labeled with hot spots. We identified several OCT features, including the gap between the inner retina and ERM, 16 inner retinal thickening, folding, ectopic inner foveal layer, 11 disorganization of the retinal inner layers (DRIL), 13 retinal cysts in the inner retina or outer nuclear layer (ONL), ONL inward projection, 17,41 outer retinal thickening, cotton ball signs, 12 disruption of the ellipsoid zone and external limiting membrane (ELM), choroidal thickness, and the presence of a pseudohole. Furthermore, 270 heat maps of profound visual impairment were combined with the alignment of the retinal pigment epithelium layer to obtain an overlap heat map.…”