INTRODUCTION: The aim of this study was to evaluate the relation between choroidal thickness (CT), central retinal thickness (CRT) and best-corrected visual acuity (BCVA) after surgery for idiopathic epiretinal membrane (iERM).

METHODS: Patients with 4 severity stages of iERM, who underwent vitrectomy with membrane- and internal limiting membrane peeling, were included in this prospective study. CRT, CT, and BCVA were assessed at baseline (BSL), 1 week, 1 and 3 months postoperatively.

RESULTS: Twenty-one eyes were phakic, 11 eyes pseudophakic at BSL, in 14 cases combined cataract surgery was performed. BCVA was highest in stage 1 and 2, lowest in stage 4 iERM (p < 0.001) and correlated with CRT. After surgery, CRT decreased and BCVA increased significantly (p < 0.05). CT did not show significant differences among stages (p = 0.23). BSL CRT did not differ between phakic and pseudophakic eyes, the least reduction after surgery was detected in patients who underwent combined cataract surgery and vitrectomy. BSL CT was greater in phakic than in pseudophakic eyes (p = 0.033). Postoperative CT decreased in pseudophakic and phakic eyes, but remained higher after combined surgery (p = 0.0048).

CONCLUSION: CT is not related to the severity of iERM. Choroidal changes did not influence the BCVA. Additional cataract surgery seems to cause longer recovery in CT and CRT.