Visual and anatomical outcomes of epiretinal membrane surgery across milder vs. severe stages: a retrospective...

Epiretinal membrane (ERM) is a common condition causing visual deterioration. However, the indication and timing for the surgical treatment of this condition have not been standardized. In this study we aimed to evaluate the anatomical and functional outcomes of mild vs severe epiretinal membrane surgery across different stages and determine the optimal timing for surgical intervention using Govetto's OCT-based classification.

This retrospective study included 46 eyes undergoing pars plana vitrectomy for ERM. Patients were stratified according to severity into Stage 2 (n = 10), Stage 3 (n = 25), and Stage 4 (n = 11) based on SD-OCT findings. Pre- and postoperative best-corrected visual acuity (BCVA), intraocular pressure (IOP), and central macular thickness (CMT) were analyzed. A short patient questionnaire was used to assess the subjective outcomes of the surgery.

Stage 4 patients had significantly worse preoperative and postoperative BCVA compared to milder stages (p = 0.007). Structural OCT abnormalities such as ectopic inner foveal layers (EIFL), inner retinal irregularity (IRI), COST (cone outer segment tip) line defects and inner segment/outer segment (IS/OS) junction disruption were significantly more frequent in Stage 4. Stage 2 showed thinner CMT and significantly better visual outcomes postoperatively. Subjective visual improvement was most notable in Stage 3 (p = 0.032).

ERM surgery in severe cases (stage 4) is associated with inferior anatomical and visual outcomes. Surgical intervention in milder cases particularly in stage 2, results in more favorable postoperative BCVA and reduced anatomical disruption. These findings support considering surgery in milder cases before the development of advanced OCT changes such as IS/OS disruption, EIFL and IRI.