Purpose: It is known that vitrectomy for idiopathic epiretinal membrane (ERM) improves best-corrected visual acuity and stereopsis as well as reduces metamorphopsia. This study aimed to investigate factors associated with improvement in stereopsis after vitrectomy in patients with ERM.
Subjects and methods: We examined 28 patients with unilateral ERM (mean age, 65.7 years) who underwent vitrectomy at the Department of Ophthalmology at Tokyo Medical University Hospital between October 2019 and March 2021. Further, internal limiting membrane peeling was performed in all patients, and cataract surgery was performed as needed. The following test items were analyzed: degree of best corrected visual acuity, metamorphopsia, and stereopsis. M-CHARTS™ was used to calculate the degree of metamorphopsia in the horizontal meridian (MH) and that of metamorphopsia in the vertical meridian (MV). In addition, the Titmus Stereo Test was used to measure stereopsis. The results of best corrected visual acuity, MH and MV, and stereopsis were analyzed before and 3 months after vitrectomy. Finally, based on the results obtained, we evaluated factors related to postoperative stereopsis.
Results: We found that the best corrected visual acuity [logarithmic minimum angle of resolution (logMAR)] (mean±standard deviation) improved significantly from 0.32±0.18 before surgery to 0.02±0.06 after surgery (p<0.0001). Moreover, MH and MV improved significantly from 1.09±0.60°before surgery to 0.62±0.59°after surgery (p<0.0001) and from 0.84±0.50°before surgery to 0.63±0.52°after surgery (p<0.05), respectively. Furthermore, stereopsis (log) improved significantly from 2.51±0.71 before surgery to 2.15±0.66 after surgery (p=0.0001). Postoperative stereopsis was found to be significantly and positively correlated with postoperative best corrected visual acuity (r=0.599, p<0.001), preoperative MH (r=0.581, p=0.001), and postoperative MH (r=0.600, p<0.001). Additionally, the results of multiple regression analysis indicated that postoperative best corrected visual acuity (β=0.348, p<0.01), preoperative MH (β=0.406, p<0.01), and postoperative MH (β=0.74, p<0.001) were important factors related to improvement in postoperative stereopsis.
Conclusion: The present study suggested that MH is an important factor related to stereopsis after vitrectomy for unilateral ERM.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 127: 839-843, 2023.