Risk Factors for Hypotony Following Sutureless Vitrectomy in Patients with Epiretinal Membrane

Purpose: To assess the risk factors for hypotony following sutureless vitrectomy in patients with epiretinal membranes (ERM). Methods: This retrospective study enrolled patients with ERM who underwent vitrectomy at the Kanazawa Medical University. An intraocular pressure of < 5 mmHg on the day following surgery was defined as the hypotony group and the other as the non-hypotony group. Background factors were compared between the two groups. Results: This study assessed 126 eyes. Thirteen eyes (10.3%) developed hypotony the day after surgery. Hypotony duration was only the next day for three eyes, within three days for four eyes, one week for five eyes, and two weeks for one eye. Comparisons between the two groups revealed no substantial differences in age, sex, 25-gauge/27-gauge, peripheral retinal tear, posterior vitreous detachment, or combined cataract surgery/vitrectomy alone. Contrastingly, significant differences were found in the axial length (p<0.05) and preoperative glaucoma eye drop use (p<0.05). Binary logistic regression analysis revealed that ≥ 26.0 mm axial length (OR 4.577, 95% confidence interval [CI] 1.17–17.91, p=0.03) and preoperative glaucoma eyedrops (OR 7.311, 95% CI 1.47–36.45, p=0.01) were significant risk factors. Conclusion: ERM patients with long axial lengths or preoperative glaucoma eye drop treatment should be carefully monitored for hypotony following vitrectomy; nevertheless, most patients spontaneously recover within a week.