Daily or Less Frequent Topical 1% Atropine Slows Defocus-Induced Myopia Progression in Contact Lens-Wearing Guinea Pigs.

Purpose: This study compared the efficacy of topical 1% atropine applied daily versus every 3 days for controlling myopia progression in guinea pigs.

Methods: To induce myopia, pigmented guinea pigs (New Zealand strain, n = 38) wore monocular -10 D rigid gas-permeable (RGP) contact lenses, which were replaced after 3 weeks with -15 diopter (D) contact lenses. Animals were treated with 1% atropine either daily (Atr-QD; n = 12), or every 3 days (Atr-Q3D; n = 11), or with artificial tears (control group; n = 15).