Correlation Between Central Macular Thickness and Visual Acuity After Vitrectomy and Internal Limiting Membrane Peeling

Purpose: To evaluate the relationship between central macular thickness (CMT) and best-corrected visual acuity (BCVA) after vitrectomy and internal limiting membrane (ILM) peeling. Methods: This multicenter, observational, retrospective study included 27 surgeons working at 22 different sites in France. Data from the preoperative, 3- to 6-month, and 1- to 2-year postoperative visits were analyzed. Etiologies of macular edema included epiretinal membrane, vitreomacular traction, diabetic macular edema, edema following retinal vein occlusion, and postsurgical cystoid macular edema. Results: A total of 879 patients were included in the study. BCVA improved from 0.44 ± 0.26 logMAR preoperatively to 0.30 ± 0.35 logMAR at 3 to 6 months, and further to 0.22 ± 0.33 logMAR at 1 to 2 years ( P < .001). CMT decreased from 422 ± 97 μm preoperatively to 360 ± 75 μm at 3 to 6 months and 337 ± 67 μm at 1 to 2 years ( P < .001). At both postoperative visits, a weak nonlinear quadratic correlation between CMT and BCVA was observed (1-3 months: R 2 = 0.08, P < .001; 1-2 years: R 2 = 0.12, P < .001). Patients with BCVA 0.1 logMAR and better had a CMT of 359 ± 52 μm (n = 237) at 3 to 6 months and 336 ± 55 μm (n = 223) at 1 to 2 years. Conclusions: After vitrectomy and ILM peeling, a nonlinear relationship between CMT and BCVA was observed, with both low and high CMT values correlating with a poor BCVA. Following surgery, the central macula tends to be thicker than in healthy eyes. The treatment of macular edema after vitrectomy and ILM peeling should account for an altered relationship between macular thickness and visual acuity.