Microcystic macular edema in eyes with idiopathic epiretinal gliosis: A retrospective analysis before and after vitreomacular surgery : Short title: microcystic macular edema in idiopathic epiretinal gliosis.

PURPOSE: To investigate incidence and clinical course of microcystic macular edema (MME) in eyes with idiopathic epiretinal membranes (iERM) before and after surgery.

METHODS

Of 1283 eyes that underwent vitrectomy with membrane peeling, 170 eyes were retrospectively analysed. All eyes had iERM and at least one postoperative control with retinal imaging. MME and cystoid macular edema (CME) were assessed by optical coherence tomography (OCT), along with demographic and clinical data. Correlations with functional outcomes were statistically significant at p < 0.05.

RESULTS

At baseline, 42 eyes (25%) had MME, 18 eyes (11%) had combined MME + CME and 110 eyes (64%) had no edema. The mean postoperative follow-up was 7.1 ± 5.9 months. All three groups showed significant improvement in visual acuity (VA), greatest in the no-edema group (p < 0.001). Incidence of MME increased with ERM severity (p = 0.033). At three months postoperatively, MME persisted in 32/159 eyes, resolved in 25, newly developed in 20, and was absent in 82/159 eyes, with a significant difference in VA between groups (p < 0.001). After 12 months, persistent MME reduced to 4/26 eyes, resolution of MME was seen in 6, new MME in 5 and 11/26 eyes still had no edema, with no significant VA between the groups (p = 0.206).

CONCLUSION

Our study demonstrates that visual recovery occurred irrespective of MME status. In advanced iERM stages, MME was more frequently observed and associated with delayed visual improvement, particularly when it developed or persisted after surgery. Despite its early effects, MME does not seem to significantly affect long-term visual outcomes.