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

Abstract

Objective: To evaluate the safety and efficacy of the relatively selective M(1)-antagonist, pirenzepine ophthalmic gel (gel), in slowing the progression of myopia in school-aged children.

Design: Parallel-group, placebo-controlled, randomized, double-masked study.

Participants: Three hundred fifty-three healthy children, 6 to 12 years old, with a spherical equivalent (SE) of -0.75 to -4.00 diopters (D) and astigmatism of <or=1.00 D. Subjects underwent a baseline complete eye examination, and regular examinations over a 1-year period. The study was conducted at 7 academic centers and clinical practices in Asia.

Intervention: Subjects received 2% gel twice daily (gel/gel), 2% gel daily (evening, placebo/gel), or vehicle twice daily (placebo/placebo) in a 2:2:1 ratio, respectively, for 1 year.

Main outcome measure: Spherical equivalent under cycloplegic refraction.

Results: At study entry, mean SE refraction was -2.4+/-0.9 D. At 12 months, there was a mean increase in myopia of 0.47 D, 0.70 D, and 0.84 D in the gel/gel, placebo/gel, and placebo/placebo groups, respectively (P<0.001 for gel/gel vs. placebo/placebo). Discontinued from the study for adverse events were 11% (31/282) of pirenzepine-treated subjects. Of the 15 serious adverse events reported in 12 subjects (all in the active groups), none was ophthalmic in nature, all subjects recovered, and only 1 (abdominal colic preceded by a flu) was judged possibly related to treatment.

Conclusions: Gel (2% twice daily) was effective and relatively safe in slowing the progression of myopia over a 1-year treatment period.