Improved Presbyopic Vision With Miotics

Abstract

Objective: To evaluate the efficacy of using a parasympathomimetic drug (carbachol) with an alpha agonist (brimonidine) to create optically beneficial miosis to reduce the effect of presbyopia.

Methods: In this prospective, double-masked, randomized, placebo-controlled clinical trial, 48 naturally emmetropic and presbyopic subjects aged between 43 and 56 years with an uncorrected distance visual acuity of at least 20/20 in both eyes without additional ocular pathology were eligible for inclusion. Subjects were divided into 2 groups. The treatment group (n=30 eyes) received single dose of 2.25% carbachol plus 0.2% brimonidine eye drops. The control group (n=18 eyes) received placebo drops. Drops were given to all subjects in a masked fashion, in their nondominant eye. The minimum posttreatment follow-up was 3 months. The subjects' pupil size and both near and distance visual acuities were evaluated before and after treatment at 1, 2, 4, 8, and 10 hr, by a masked examiner at the same room illumination.

Results: Statistically significant improvement in near visual acuity was achieved in all subjects who received carbachol plus brimonidine drops (P<0.0001). In this masked study, all subjects liked and would use this therapy if it was available. None would use the placebo. There was no evidence of tolerance or tachyphylaxis during the study period.

Conclusions: Improving the depth of focus by making the pupil smaller caused statistically significant improvement in near visual acuity in emmetropic presbyopic subjects. Carbachol plus brimonidine seem to be an acceptable and safe alternative to corrective lenses and surgical procedures.