Long-Term Outcomes in Early vs. Limited Response to Anti-VEGF Treatment for Retinal Vein Occlusion.

OBJECTIVE: Macular edema secondary to retinal vein occlusion (RVO) is a sight-threatening condition. Previous studies showed that early responders (ER) who respond well to anti-VEGF injections within 3 months of treatment have better outcomes as measured by best visual acuity (BVA) and central subfield thickness (CST) at 12 months post injection initiation compared to limited early responders (LER). This study analyzed whether ER eyes continue to respond better than LER eyes over longer periods. This study also aimed to identify baseline comorbidities associated with response status.

DESIGN: Retrospective Cohort Study PARTICIPANTS: Patients above age 18 with RVO-related macular edema treated with anti-VEGF injections METHODS: Patients were categorized as ER or LER. LER eyes were defined as having CST reduction < 10%, BVA gain < 5 ETDRS letters, or both at 3-months after anti-VEGF initiation. BVA and CST changes over the 24-month and 36-month period following first anti-VEGF treatment were compared between ER and LER. Patient characteristics and systemic comorbidities were identified by chart review. Statistical analysis involved Levene test, Welch's t-test, and Welch's ANOVA.

MAIN OUTCOME MEASURES: BVA and CST changes over the initial 24-month and 36-month period following treatment RESULTS: The 24-month cohort included 68 ER and 39 LER and the 36-month cohort included 58 ER and 33 LER. At the 24-month time point, there were significant differences in BVA and CST gains between ER (+19.8 letters, -221.um) and LER (-2.4 letters, -90.1 um) (p < 0.0001, p < 0.01). Similarly, at 36 months, there were significant differences in BVA and CST gains between ER (+17.7 letters, -229.3 um) and LER (+1.3 letters, -128 um) (p < 0.001, p < 0.05). After controlling for differences in baseline BVA and CST, only the 24-month change in BVA remained significant (p < 0.001). There were no significant associations between response status and cardiopulmonary, endocrine, and oncologic comorbidities.

CONCLUSIONS: ER eyes with BRVO and CRVO have better functional responses to anti-VEGF injections at 24 months compared to LER eyes even after controlling for baseline differences. Early identification of eyes as ER or LER in BRVO and CRVO may predict long-term functional prognoses.