Two-year multicenter, randomized, double-masked, placebo-controlled, parallel safety and efficacy study, of 2% pirenzepine ophthalmic gel in children with myopia

PURPOSE To evaluate if the safety and efficacy of the relatively selective All-antagonist, pirenzepine, in slowing the progression of myopia in children is sustained over a 2-year period. METHODS This was a multicenter, parallel-group, placebo-controlled, double-masked, randomized clinical trial. Enrolled were children aged 8 to 12 years, with entry spherical equivalent refractive error of -0.75 to -4.00 D and astigmatism <= 1.00 D. Patients were randomized in a 2:1 ratio to receive 2% pirenzepine ophthalmic gel or a placebo control (vehicle), twice daily to each eye. The main outcome measure was, is spherical equivalent refractive error via cycloplegic autorefraction. RESULTS At study entry, spherical equivalent was -2.10 +/- 0.90 D (mean +/- SD) for the pirenzepine group (n = 117) and -1.93 +/- 0.83 D for the placebo group (n = 57;p = 0.22). At I year, there was a mean increase in myopia of 0.26 D in the pirenzepine group versus 0.53 D in the placebo group (p < 0.001). Eighty-four patients elected to continue for a second year (pirenzepine = 53, placebo = 3 1). At 2 years, die mean increase in myopia was 0.58 ID for the pirenzepine group and 0.99 D for the placebo group (p = 0.008). Thirteen (11%) pirenzepine patients dropped out due to adverse effects in the first year, and 1. did so in the second year. CONCLUSIONS Pirenzepine ophthalmic gel 2% was effective compared with placebo in slowing the progression of myopia over a 2-year treatment period and demonstrated a clinically re acceptable safety profile.