Analysis of Choroidal Thickness Change after 25-Gauge Vitrectomy for Idiopathic Epiretinal Membrane with or without Phacoemulsification and Intraocular Lens Implantation

Purpose: This study aimed to evaluate choroidal thickness modifications before and after vitrectomy with or without phacoemulsification for idiopathic epiretinal membrane in the operated eye and in the unaffected fellow eye. Methods: In total, 53 eyes of 53 patients underwent 25-gauge pars plana vitrectomy plus internal limiting membrane peeling and air tamponade. Twenty-seven eyes underwent combined surgery with phacoemulsification and intraocular lens implantation. Choroidal thickness was measured using enhanced deep image spectral-domain optical coherence tomography at the fovea and at 500 and 2,500 μm from the fovea. Fellow eyes without any previous ocular surgery history served as controls. Results: Baseline comparison did not show significant differences between study and fellow eyes (p > 0.05). Choroidal thickness significantly decreased in the subfoveal area (p = 0.004) as well as at 500 μm (p = 0.026) and 2,500 μm nasally (p = 0.019) and at 500 μm (p = 0.039) and 2,500 μm (p = 0.005) temporally to the fovea. No significant changes were observed postoperatively in the superior and inferior areas (p > 0.05). No differences were found between eyes which underwent combined surgery and those which underwent vitrectomy alone (p > 0.05). The unaffected eyes did not show any significant changes (p > 0.05). Conclusions: Comparison of baseline values did not show any differences between affected and unaffected eyes, meaning that choroidal thickness was not influenced by the development of epiretinal membrane. Vitrectomy plus epiretinal and inner limiting membrane removal may influence choroidal homeostasis, leading to a decrease in choroidal thickness in the subfoveal, nasal, and temporal areas. Combined surgery did not show significant differences when compared to vitrectomy alone.