Pupillary dilation with tropicamide 1% for funduscopic screening. A study of duration of action

Primary care practitioners omit pupillary dilation from funduscopic examination, possibly because of time constraints, poor patient compliance, or fear of adverse reactions. Nevertheless, the omission of this procedure may lead to the inadequate visualization of the fundus for screening. We administered a topical solution of 1% tropicamide to 30 adults to determine the course of pupillary dilation over time and whether adequate dilation could be attained within a routine clinic visit. Pupil diameters were measured every 5 minutes in a 30-minute period. The initial mean pupillary diameter was 2.4 mm and the endpoint was 5.5. Dilation was significantly slower in those older than 50 years of age. However, at 15 minutes 87% of the patients, regardless of age, had achieved dilation to at least 4 mm, which should be sufficient for screening under most circumstances. We conclude that adequate pupillary dilation in adults usually can be achieved within the time frame of a routine office visit and thus should not be a deterrent to routine funduscopic screening by primary care practitioners.