Compliance to Intravitreal Anti-Vascular Endothelial Growth Factors for Treatment of Retinal Diseases in Nigerians: A Retrospective Multicenter Study

Background Little is known about compliance with intravitreal anti-vascular endothelial growth factor (VEGF) therapy for the treatment of macular and retinovascular diseases among Nigerians and Africans. The objective of this study is to measure compliance to 3 or more and 6 or more intravitreal anti-VEGF injections for common macular and retinovascular diseases in Nigerian clinics and evaluate the impact on visual outcomes. Method Retrospective multicenter chart review of 622 eyes/528 patients diagnosed with AMD, DME, RVOs (BRVO, CRVO, HRVO), and non-AMD CNVM from five clinics (urban, semi-urban, and rural), collecting demographics, diagnosis, injection type/number, pre-/post-BCVA (converted to LogMAR), and follow-up. Treatments were intravitreal Bevacizumab (Avastin), Ranibizumab (Patizra), and Aflibercept (Eylea). Definitions of compliance: compliant = ≥ 3 injections (standard loading), also reported ≥ 6 injections. Results Overall compliance to ≥ 3 injections was 47.5%, and 10.1% for ≥ 6 injections. Compliance to ≥ 3 injections by diagnosis was as follows: AMD 50.4%, Non-AMD CNVM 58.2%, BRVO 44.8%, CRVO 44.0%, HRVO 46.7%, DME 40.6%. Age (P = 0.264) and sex (P = 0.817) did not affect compliance to ≥ 3 injections. Clinic location significantly influenced compliance with ≥ 3 injections (P = 0.00), but not with 6 injections (P = 0.105). The highest rates of compliance with ≥ 3 injections were observed in urban tertiary centers. Injection type and cost were not significant factors (P = 0.36). Eyes with ≥ 3 injections achieved better vision (≥ 6/18) across all diagnoses; the most notable improvements were in CNVM (+ 41.4%) and BRVO (+ 35%). Statistically significant LogMAR improvements were seen in CRVO (p = 0.049) and DME (p = 0.043). Conclusions Real-world compliance is significantly lower than ideal. Urban and tertiary clinics show better adherence. Receiving the recommended loading doses is associated with improved visual outcomes for most diagnoses. Understanding the reasons for non-compliance and addressing them will improve treatment outcomes for more Nigerian and presumably African patients receiving anti-VEGF drugs.