In Vitro Stability and Preclinical Safety Evaluation of High-Dose Intravitreal Topotecan in Rabbits: Impact of Dose and Concentration

This study evaluated the stability and safety of high-dose intravitreal topotecan in 24 non-tumor-bearing New Zealand White rabbits. Topotecan solutions remained stable over 1 month. Rabbits received three monthly doses of topotecan (50μg, 100μg, and 200μg) or vehicle, with no systemic toxicity observed. Doses up to 100μg showed no ocular damage, but 200μg doses caused localized retinal changes and decreased electroretinography wave amplitudes. The findings suggest that while lower doses are safe, higher doses may cause retinal alterations, informing potential clinical use for severe eye conditions.