Role of caffeine in slowing progression of myopia: 1-year results from a prospective, longitudinal clinical trial

To determine the role of topical caffeine in slowing progression of myopia, both as a standalone treatment and in combination with atropine. In a prospective, randomized, dispensing clinical trial, 96 children with myopia, aged 6-13 years, spherical equivalent (SE) from -0.50 diopters (D) to -6.00 D and astigmatism less than 2.00 D were randomly assigned to nightly use of either 2 % caffeine, 0.02 % atropine with 2 % caffeine (combination) or 0.02 % atropine eye drops. An additional 86 children with myopia were enrolled in a concurrent parallel group to wear single-vision (SV) spectacles. The primary outcomes were changes in SE and axial length (AL) over a period of 12 months for each group. All groups progressed in myopia. At 12 months, the mean change in SE/AL was -0.76 ± 0.51 D / 0.37 ± 0.20 mm and -0.70 ± 0.55 D / 0.35 ± 0.23 mm with SV and 2 % caffeine, respectively. In comparison, progression was slower at -0.46 ± 0.50 D / 0.24 ± 0.19 mm and -0.47 ± 0.38 D / 0.23 ± 0.18 mm with atropine monotherapy and combination groups, respectively. Compared to the change in AL with SV, the change in AL was significantly less with 0.02 % atropine and the combination group (post hoc analysis, P = 0.024 and 0.007, respectively). Similarly, the change in SE was significantly less with 0.02 % atropine compared to the SV group (P = 0.027). Used as a standalone treatment, topical 2 % caffeine did not slow myopia progression. When combined with atropine, caffeine had no impact on the efficacy of atropine in slowing myopia.