Intracameral Concentration and Safety Profile of High Concentration Ganciclovir Eyedrop in a Rabbit Model

PURPOSE: This study aimed to evaluate the efficacy and safety of topically administered ganciclovir (GC) eye drops at varying concentrations. METHODS: = 3 per group): control (saline), 0.15%, 2%, 4%, and 8% GC eye drops. GC eye drops were applied to both eyes 4 times a day for 10 days. The concentration of GC in the aqueous humor was measured using liquid chromatography-tandem mass spectrometry. Ocular toxicity scores were graded using slit-lamp microscopy. Specular microscopy was performed after final instillation. Corneal tissues were analyzed for scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Intraocular pressure (IOP) was also measured. RESULTS: = 0.004, K-W test). Total ocular surface toxicity scores rose with increasing concentrations, with the most pronounced toxicity observed in the 8% group. Specular microscopy and SEM showed no significant differences in endothelial cell density or morphology. TEM revealed increased cell vacuoles in the 8% group, though intercellular junctions remained intact. There were no significant differences in IOP values across all groups. CONCLUSIONS: Topical GC achieved effective ocular penetration, reaching concentrations above the 50% inhibitory dose for cytomegalovirus replication at 2% or higher. Dose-dependent ocular surface toxicity was observed, particularly at higher concentrations. However, no structural or cellular damage to the corneal endothelium was detected.