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

J AAPOS. 2008 Aug;12(4):332-9. doi: 10.1016/j.jaapos.2007.10.014. Epub 2008 Mar 24.


Purpose: To evaluate if the safety and efficacy of the relatively selective M1-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 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 1 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 = 31). At 2 years, the mean increase in myopia was 0.58 D 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 acceptable safety profile.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Topical
  • Child
  • Double-Blind Method
  • Follow-Up Studies
  • Gels
  • Humans
  • Muscarinic Antagonists / administration & dosage*
  • Myopia / drug therapy*
  • Myopia / physiopathology
  • Pirenzepine / administration & dosage*
  • Refraction, Ocular / drug effects
  • Retrospective Studies
  • Time Factors
  • Treatment Outcome


  • Gels
  • Muscarinic Antagonists
  • Pirenzepine