Intraretinal changes in idiopathic versus diabetic epiretinal membranes after macular peeling

Abstract

IntroductionEpiretinal traction is not responsible only for epiretinal but also intraretinal changes. This study aims to describe structural and vascular intraretinal changes after macular peeling in idiopathic (iERM) vs diabetic ERM (dERM).MethodsWe conducted a prospective interventional study on forty-two eyes, 23 with iERMs and 19 with dERMs, undergoing ERM-ILM peeling. We performed SD-OCT preoperatively, 1 and 6 months postoperatively to assess central macular thickness (CMT), intraretinal cysts (IC) and/or continuous ectopic inner foveal layers (CEIFL), superficial and deep capillary free zone (CFZ) area on OCT-A. Glial fibrillary acidic protein (GFAP), as a Müller cells marker, was detected immunohistochemically on ILM specimens, to assess Müller cells iatrogenic damage.ResultsThe CEIFLs were significantly more common in iERMs (12 (52.2%) in iERMs vs 2 (10.5%) in dERMs, p = 0.004), whereas ICs in dERMs (6 (26.1%) in iERMs vs 17 (89.5%) in dERMs, p<0.001). Median preoperative and postoperative BCVA was 20/50 [20/40-20/66] and 20/33 [20/25-20/40] in iERMs and 20/100 [20/66-20/200] and 20/50 [20/50-20/66] in dERMs, respectively. Median preoperative and postoperative CMT was 423 [370–488] and 364 [329–382] μm in iERM group and 465 [447–503] and 378 [359–433] μm in dERM group, respectively. The BCVA improvement and reduction of CMT thickness were significant in both groups (p<0.001). The presence of CEIFL was associated with lower BCVA in iERMs. Deep CFZ network significantly increased only in dERMs, passing from 0.34 [0.29–0.42] mm2 preoperatively to 0.56 [0.46–0.6] mm2 at 6-month follow-up (p<0.001). The GFAP expression was significantly higher in dERMs (p = 0.001).ConclusionThe intraretinal changes are different in iERMs and dERMs, as increased expression of CEIFLs in iERMs vs ICs in dERMs. The CEIFLs are associated with worse anatomical and functional outcomes in iERMs, whereas GFAP espression in peeled ILMs is higher in dERMs.

Epiretinal Membrane Peeling in Eyes with Retinal Vein Occlusion: Visual and Morphologic Outcomes

“…The relative abundance of these components within each ERM case reflects the underlying etiology and the severity of the disease or its duration. In retinal ischemia or inflammation, such as in diabetic retinopathy or RVO, activation of Mu ¨ller cells induces the upregulation of glial fibrillary acidic protein and vimentin, with reactive gliosis and ERM formation [19,20]. As platelet-derived growth factor A (PDGF A) and VEGF receptors are expressed within ERM cells, intravitreal proangiogenic cytokines may accelerate ERM progression [21].…”

Efficacy of Combined Vitrectomy with Intravitreal Corticosteroid Injection for Idiopathic Epiretinal Membrane Removal on Anatomical and Functional Outcomes: A Meta-Analysis

“…Massin et al [25] explained that the partial recovery of macular morphology may be because of chronic deformation exerted by ERM traction and a certain degree of intra-retinal gliosis that prevents the macula from returning to its normal profile. Moreover, in a histological and immunohistochemical study by Romano et al [26], the authors demonstrated that chronic tractional stress exerted by idiopathic ERM could mechanically displace inner retinal layers centripetally and result in irreversible macular damage. Further, chronic tractional stress also acts on healthy Muller cells inducing reactive intra-retinal gliosis.…”

“…Although some reports have emphasized that persistent macular thickening after ERM surgery is more likely related to mechanical traction [25][26][27], the pull force on the retinal surface resulting in cytotoxic injury and vascular damage may be the other important cause of postoperative persistent macular thickening and cystoid changes in the macula. In a study by Frisina et al [7], the incidence rate of cystoid macular edema (CME) after ERM surgery was 12.8%.…”

A novel quantitative analysis method for idiopathic epiretinal membrane

“…Interestingly, we found a significant correlation between BCVA at 6 months and RI at baseline and in particular, cases with higher baseline RI (indicative here of larger relaxation after surgery) reached a higher BCVA at 6 months ( Fig 5 ). Relaxation after surgery strictly depends on the grade of intra-retinal and epiretinal fibrosis, which is the result of the bond between Müller cells and ILM sustained by glial fibrillary acidic protein (GFAP) overexpression [ 20 ].…”