# 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

## TL;DR

This study examines how microcystic macular edema (MME) affects vision in patients with epiretinal membranes before and after surgery, finding that MME does not significantly impact long-term outcomes.

## Contribution

The study provides new insights into the variable clinical course of MME in iERM patients and its limited long-term impact on visual function.

## Key findings

- MME was present in 25% of eyes at baseline and showed variable postoperative resolution.
- MME was more common in advanced iERM stages and linked to delayed visual recovery.
- Long-term visual outcomes were not significantly affected by MME status.

## Abstract

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

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.

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).

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.

The online version contains supplementary material available at 10.1007/s00417-025-07006-1.

Recent research has shown microcystic macular edema (MME) to occur more frequently in eyes with idiopathic epiretinal membrane (iERM).

Recent research has shown microcystic macular edema (MME) to occur more frequently in eyes with idiopathic epiretinal membrane (iERM).

Our study demonstrated that the incidence and short-term postoperative course of MME in iERM patients exhibit considerable clinical variability. The often unpredictable resolution may reflect underlying heterogeneity in disease mechanisms.The presence of MME was more frequent in advanced ERM stages and may be linked to delayed visual recovery, particularly when it develops or persists after surgery.MME appears to have limited impact on long-term visual function.

Our study demonstrated that the incidence and short-term postoperative course of MME in iERM patients exhibit considerable clinical variability. The often unpredictable resolution may reflect underlying heterogeneity in disease mechanisms.

The presence of MME was more frequent in advanced ERM stages and may be linked to delayed visual recovery, particularly when it develops or persists after surgery.

MME appears to have limited impact on long-term visual function.

The online version contains supplementary material available at 10.1007/s00417-025-07006-1.