Pharmacodynamics of subconjunctival gentamicin after experimental cataract operations and traumatic lacerations.

We addressed the concern whether retinal toxicity could occur with subconjunctival gentamicin injections after cataract operations or traumatic corneoscleral lacerations. The lacerations were created along the superior limbus of rabbit eyes and the lenses removed. We sutured the right eyes to mimic a cataract operation and the left eyes remained unsutured to mimic a traumatic corneoscleral laceration. Vitreous humor samples were obtained at 1, 2, 4, 8 and 12 hours after the subconjunctival injection, but in no case did vitreal concentration approach retinotoxic levels (> 133 micrograms/ml).