The Effects of Low Dose Atropine on Choroidal Thickness

Atropine eye drops are considered to be an effective form of myopia control in human eyes. However, the mechanism by which it exerts it effects are not fully understood. Thickening of the choroid subsequent to atropine administration may play an important role in the mechanisms by which atropine induces myopia control. Literature also notes that choroidal thickness undergoes diurnal variations, which is a variable that will be controlled in this study in order to examine atropine's effects on different baseline choroidal thicknesses. The purpose of the proposed study is to characterize better the influence of atropine on choroid thickness. The study aims are to: 1. Determine the effect of low dose concentration of topical atropine (0.1% and 0.01%) on choroid thickness 2. Determine the effect of topical atropine on choroid thickness in relationship to baseline thickness throughout the day and after one week of daily instillation Hypothesis: Atropine's effect on choroidal thickness will be dependent on the subject's baseline thickness measurements, at a designated time of the day when the choroid is at its thinnest.