A study comparing baseline and best-corrected visual acuity after iodine-125 episcleral brachytherapy in uveal melanoma

Purpose The aim of this study was to analyze the course of visual acuity (VA) in visual outcomes of patients treated with iodine-125 (125I) brachytherapy in our center, based on original VA before treatment. Material and methods Visual acuity was prospectively assessed using a case series of 305 patients treated with 125I between 1996 and 2022. To examine how VA behaves over time, we divided patient sample into 4 groups: (1) Patients with visual acuity of less than V ≤ 0.1 at baseline; (2) Patients with low to moderate VA, ranging 0.1 < V < 0.4; (3) Patients with moderate-high VA, ranging 0.4 < V < 0.8; (4) Patients with very high VA of V > 0.8. Each of the four groups was studied separately over a 60-month period to determine the percentage of patients with VA improvement, worsening, or with the same VA status. Finally, visual outcomes over time were estimated with 95% confidence interval (CI) using Kaplan-Meier analysis, and VA maintenance rates were reported at 1, 3, 5, 10, 15, and 20 years of follow-up. Results The median follow-up time was 78.2 months (range, 6-254 months). The cumulative probabilities of survival analysis at 1, 3, 5, and 10 years were 16%, 3%, 2%, and none for the first sub-group; 46%, 20%, 17%, and 14% for the second; 65%, 53%, 29%, and 15% for the third; and 86%, 56%, 48%, and 41% for the fourth sub-group. The median survival in years was 0.30, 0.80, 3.10, and 4.40 for each sub-cohort, respectively. Conclusions The decrease and maintenance of VA depends on the initial VA of patients. Most patients experience a marked worsening of their VA, regardless of their VA status before treatment with episcleral brachytherapy. Patients with a higher baseline VA retain VA best over time.