Characteristics of Patients Who Drop Out of Anti-Vascular Endothelial Growth Factor Therapy for Macular Edema Associated with Branch Retinal Vein Occlusion

Abstract

Purpose. To investigate the dropout rate of anti-vascular endothelial growth factor (VEGF) treatment for macular edema (ME) secondary to branch retinal vein occlusion (BRVO) and identify the characteristics of dropout cases. Methods. We studied 235 eyes of 235 treatment-naïve BRVO-ME patients receiving intravitreal injection of ranibizumab. Additional intravitreal anti-VEGF drug was given when ME relapsed or persisted, and photocoagulation was performed as needed. Adherence until treatment completion was defined as disappearance of ME within 2 years after the first injection without recurrence for more than 6 months or mild ME remaining but no visual deterioration for more than 6 months without additional anti-VEGF drug. In patients with ME recurrence, those who were followed for more than 2 years were considered adherence, and those followed for less than 2 years were considered dropout. The clinical course and background of the two groups were compared. Results. 179 patients (76.2%) adhered to treatment and 56 patients (23.8%) dropped out. Mean follow-up periods in adherence and dropout groups were 23.4 and 7.1 months, respectively. There were no significant differences between the two groups in demographic and baseline factors of age, gender ratio, distance from home to hospital, visual acuity, and foveal thickness (FT). At the last follow-up, visual acuity was significantly poorer in the dropout group than in the adherence group (0.23 vs. 0.11 logMAR, p=0.003), and FT was significantly greater in the dropout group than in the adherence group (316 vs. 273 µm, p=0.002). Reasons for dropout included patient declining further treatment in 12.5%, progression of dementia in 8.9%, others, and unknown in 64.3%. Conclusion. The clinical outcome of patients who dropped out of anti-VEGF therapy for BRVO-ME was worse compared to patients who adhered to therapy, and the reasons for discontinuation varied.