Is it necessary to wait several minutes between applications of different topical ophthalmic solutions? A preliminary study with tropicamide eye drops in healthy dogs.

Objective: To evaluate the efficacy of topical tropicamide when placed at different time intervals before or after a saline drop.

Animals Studied: Eight healthy Labrador and golden retriever dogs.

Procedures: The effect of 1% tropicamide on pupillary diameter (PD) was measured over 240 min when administered alone (control) and then 1 and 5 min prior to, or following, application of a saline drop, with 1-week washout between each of the five trials.