INVESTIGATION OF INCIDENCE AND CAUSES OF ACUTE VISION LOSS DURING ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR THERAPY FOR NEOVASCULAR AGE-RELATED MACULAR DEGENERATION DURING A FOUR-YEAR FOLLOW-UP.

PURPOSE: To investigate the incidence, risk factors, and outcomes of patients with age-related macular degeneration who experienced acute vision loss despite periodic injections of anti-vascular endothelial growth factor treatment for 4 years. METHODS: This retrospective cohort study included patients who were diagnosed with treatment-naive neovascular age-related macular degeneration and completed a 4-year follow-up. The incidence and risk factors for the occurrence of three or more lines of visual loss at every checkup were investigated. RESULTS: The analysis included 76 eyes of 76 patients. Acute vision loss occurred in 30 eyes (39.5%) over 4 years. Lower baseline best-corrected visual acuity and disrupted ellipsoid zone were independent predictors of vision loss occurrence. Although the causes and timing of visual acuity loss varied, retinal pigment epithelium tears were observed only in the first year. Most patients (86.7%) who experienced vision loss recovered their vision to pre-loss levels at least once; however, the final best-corrected visual acuity was worse than that in the group that did not experience acute vision loss. CONCLUSION: Approximately half of the patients with age-related macular degeneration experienced acute vision loss during a 4-year follow-up, despite continuous anti-vascular endothelial growth factor treatment. Most patients recovered from vision losses temporarily; however, they experienced worse visual outcomes subsequently.