Bilateral improvement in age-related macular degeneration following unilateral Aflibercept injection.

Background: The "fellow-eye effect" in anti-vascular endothelial growth factor (anti-VEGF) therapy is a rare phenomenon, particularly with aflibercept. This case report documents the first instance of this effect in Pakistan, highlighting its significance in a resource-limited setting where recent regulatory changes have restricted treatment options for age-related macular degeneration (AMD).

Case presentation: A 62-year-old male presented with bilateral central vision loss due to neovascular AMD. Optical Coherence Tomography revealed serous subretinal fluid in both eyes. Due to financial constraints, only the right eye received a single 2 mg intravitreal aflibercept injection. Remarkably, at the four-week follow-up, both eyes showed significant improvement. Visual acuity improved from 6/12 to 6/9 in the treated right eye and from 6/15 to 6/12 in the untreated left eye. OCT scans demonstrated bilateral resorption of subretinal fluid. At three months, complete fluid resorption was observed in both eyes, with visual acuity improving to 6/6 bilaterally.

Conclusions: This case underscores the potential of the "fellow-eye effect" in anti-VEGF therapy, particularly with aflibercept, in treating bilateral AMD. It highlights a possible strategy for optimizing treatment regimens and reducing costs in resource-limited settings. However, it also raises concerns about systemic absorption and potential risks. The findings emphasize the need for further research on the pharmacokinetics of anti-VEGF agents, personalized treatment plans, and alternative therapies. This case is particularly significant in the context of Pakistan's recent ban on bevacizumab, underscoring the urgent need for accessible and affordable AMD treatments in developing countries.