The most likely effective treatment to slow myopia progression thus far is anti-muscarinic topical medication. However, side effects of these medications include light sensitivity and near blur. Also, they are not yet commercially available, so their use is limited and not practical. Further information is required for other methods of myopia control, such as the use of corneal reshaping contact lenses or bifocal soft contact lenses (BSCLs) with a distance center are promising, but currently no published randomized clinical trials exist.
One-year multicenter, double-masked, placebo-controlled, parallel safety and efficacy study of 2% pirenzepine ophthalmic gel in children with myopia.
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.
                Parallel-group, placebo-controlled, randomized, double-masked study.
                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.
                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.
                Spherical equivalent under cycloplegic refraction.
                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.
                Gel (2% twice daily) was effective and relatively safe in slowing the progression of myopia over a 1-year treatment period.