Postoperative outcomes of idiopathic epiretinal membrane associated with foveoschisis

Aims To analyse the prevalence and postoperative outcomes of a particular form of epiretinal membrane (ERM) with foveoschisis-like stretched hyporeflective spaces in emmetropic eyes. Methods A retrospective study of all consecutive eyes operated for primary ERM over a 46-month period was conducted. The presence of foveoschisis-like stretched hyporeflective spaces was assessed on the preoperative optical coherence tomography B-scan in all eyes. Highly myopic eyes were excluded. Preoperative and postoperative characteristics of eyes with foveoschisis were compared with those of a control group of 100 consecutive eyes with primary ERM without cystoid spaces. Results Of 544 eyes with primary ERM, 17 had foveoschisis, corresponding to a prevalence of 3.1%. After a mean postoperative follow-up of 17.9 +/- 10.9 months, the foveoschisis had completely resolved in 76.5% of eyes (n=13/17). In the four eyes (23.5%) with persistent foveoschisis, the remaining hyporeflective cystoid spaces were located exclusively in the inner nuclear layer. The postoperative visual acuity and central macular thickness did not differ between both groups at the final visit. However, an acute postoperative macular oedema occurred in 24% (n=4/17) of cases (vs 3% in the control group; p=0.0084). Conclusion Foveoschisis was found in about 3% of eyes with idiopathic ERM. After peeling, the foveoschisis usually resolves completely with functional outcomes similar to those achieved with other primary ERM. However, this feature was associated with a higher risk of postoperative macular oedema (in 1/4 of cases).