Epiretinal membranes (ERM) are a macular disorder leading to metamorphopsia and a decrease in visual acuity. Peeling of ERM during vitrectomy is, up to date, the only possible treatment option, opening chances for improvements of visual acuity and metamorphopsia. Occurrence of new intraretinal cystoid changes was described to be associated with a lower level of visual acuity after surgery, compared to patients, that never had intraretinal cystoid changes Aim of our study was to analyze development of new intraretinal cystoid changes after vitrectomy with membrane peeling with respect to postsurgical treatment strategies.

Epiretinal membranes (ERM) are a macular disorder leading to metamorphopsia and a decrease in visual acuity. While ERM are rare among young people, they have prevalence rates of up to 30% in the age groups of 70 years or older. Peeling of ERM during vitrectomy is, up to date, the only possible treatment option, opening chances for improvements of visual acuity and metamorphopsia. Nevertheless, there is a risk for development of new intraretinal cystoid changes after peeling of ERM in about 10% of patients. Preoperative presence of intraretinal cystoid changes was already described as a risk factor for postsurgical presence of intraretinal cystoid changes and and occurrence of new intraretinal cystoid changes was described to be associated with a lower level of visual acuity after surgery, compared to patients, that never had intraretinal cystoid changes. Biomarker in presurgical optical coherence tomography (OCT) have been described to be associated with postsurgical results. Using a multivariable approach of analysis, presurgical DRIL and higher central macular thickness (CMT) were significant negative predictors on postsurgical visual acuity three months after surgery. However, influence of preoperative OCT biomarkers on development of new postsurgical intraretinal cystoid changes was not examined in theses studies. Aim of our study was to analyze development of new intraretinal cystoid changes after vitrectomy with membrane peeling with respect to postsurgical treatment strategies.

Inclusion Criteria:

• presence of an idiopathic ERM with decrease in visual acuity affecting activities of the daily life
• undergone pars plana vitrectomy with membrane peeling with application of periocular triamcinolone acetonide and a prolonged application of steroidal eye drops for three months after surgery, performed by a single surgeon in the time period from 01/08/2020 to 31/05/2023.
• presence of a follow-up examination at our department three months after surgery (+-1 month), including OCT with accurate image quality for analyzing the presence or absence of intraretinal cystoid changes and visual acuity testing.
• age of 18 years of older.

Exclusion Criteria:

• age below 18 years

The study population consists of patients having undergone pars plana vitrectomy with membrane peeling with application of periocular triamcinolone acetonide and a prolonged application of steroidal eye drops after surgery for at least 3 months. To examine differences in development of new postoperative cystoid changes outcomes will be compared with a historical group of patients, that did not receive periocular triamcinolone acetonide and had a postoperative application of steroidal eye drops for one month.