Wearing-Off Period of Pharmacological Dilation and Anisocoria

Students at the School of Medicine Greenville will be asked to participate in this study. The aim of this study is to better understand when medical imaging is needed for patients with anisocoria (unequal pupil size). Participation in the study includes up to 3 visits over a period of one week. Each study visit will last about 30 minutes. At the first visit, participants will be screened for hyperopia using a phoropter, have their intraocular pressures taken using a tono-pen, and have their iridocorneal angle measured using gonioscopy at the ophthalmology clinic. Proparacaine hydrochloride 0.5% eye drops will be used to numb the eyes before measuring intraocular pressures and prior to gonio lens exam. Participants will also be asked to complete three forms. Participants will be asked to return to the clinic on a scheduled day within one week of the screening visit to have their left eye dilated. At this visit, the diameter of the pupil will be measured using a Near card in a windowless room with a set light-level. Then, the participant will receive one drop of tropicamide in the left eye. After the drops have had time to take effect, which will be about 20-30 minutes later, the diameter of the pupil will be measured again. Participants will then be asked to return to the clinic in 3-4 hours. At this time, the diameter of the pupil will be measured again. The third type of eye drop used in this study is 1% pilocarpine. 1 % pilocarpine will briefly constrict the eyes. One drop of 1% pilocarpine will be administered to left eye, and the change in pupillary diameter will be measured, if any. It will take about 10-15 minutes for the 1% pilocarpine to take effect. Participants may be required to attend 2 additional 30-minute visits on a third day depending on how their eyes respond to the drops. This study will recruit about 10-15 participants.