Two-year multicenter, randomized, double-masked, placebo-controlled, parallel safety and efficacy study of 2% pirenzepine ophthalmic gel in children with myopia.
OBJECTIVE
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.
Siatkowski
R Michael
RM
Dean McGee Eye Institute/University of Oklahoma Department of Ophthalmology, Oklahoma City, Oklahoma. USA.
Cotter
Susan A
SA
Crockett
R S
RS
Miller
Joseph M
JM
Novack
Gary D
GD
Zadnik
Karla
K
D000287:Administration, Topical; D002648:Child; D004311:Double-Blind Method; D005500:Follow-Up Studies; D005782:Gels; D006801:Humans; D018727:Muscarinic Antagonists / Q000008:administration & dosage*; D009216:Myopia / Q000188:drug therapy* / Q000503:physiopathology; D010890:Pirenzepine / Q000008:administration & dosage*; D012029:Refraction, Ocular / Q000187:drug effects; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
D005782:Gels; D018727:Muscarinic Antagonists; D010890:Pirenzepine