The Effects of Low Viscosity Chloroprocaine Ophthalmic Gel 3% on the Bactericidal Action of Povidone-Iodine: A Comparison vs Tetracaine 0.5% Solution.

Choice in vehicle plays a large role in drug delivery with topical ophthalmic medications. One strategy to increase efficacy is by increasing the ocular surface contact time of a drug on the eye, primarily by increasing the viscosity of the vehicle. However, studies have demonstrated that high viscosity topical medications act as a barrier to subsequent drops. This poses a serious issue in pre-operative prophylaxis, as high viscosity vehicles may block the bactericidal action of povidone-iodine. This has been supported by in vitro studies of Akten (lidocaine 3.5%) gel. Akten gel has a viscosity between 4000-9000 cps. Iheezo has a viscosity between 1200-2000 cps. Generic tetracaine 0.5% has a viscosity between 15-25cps. Healthy human tears have a viscosity of around 8 cps. For a vehicle to not act as a barrier to subsequent drops, it is believed that the viscosity should be close to human tears. This study theorizes that Iheezo's lower viscosity will not act as a barrier to the bactericidal action of Povidone-iodine 5%. This is a single site, prospective, randomized, patient masked, open-label study evaluating the effects of Iheezo (chloroprocaine HCl ophthalmic gel 3%) and how it may interact with povidone-iodine compared to tetracaine 0.5% ophthalmic solution. Consented patients will have their eyes randomized, one receiving Iheezo and the other tetracaine 0.5% ophthalmic solution.