Pupillometry Study of Brimonidine Tartrate 0.2% and Apraclonidine 0.5%

Besada, Eulogio OD, MS, FAAO
Reed, Kimberly OD, FAAO
Najman, Perla OD
Shechtman, Diana OD, FAAO
Hardigan, Patrick PhD

From Nova Southeastern University College of Optometry, Ft Lauderdale, Florida (Dr Besada, Dr Reed, Dr Najman, Dr Shechtman), and College of Osteopathic Medicine, Nova Southeastern University, Ft Lauderdale, Florida (Dr Hardigan). Submitted for publication July 7, 2010; revised version accepted September 5, 2010. Address for correspondence: Eulogio Besada, OD, MS, FAAO, Nova Southeastern University College of Optometry, 3200 S University Drive, Ft Lauderdale, FL 33328;
e-mail: [email protected].

The Journal of Clinical Pharmacology 51(12):p 1690-1695, December 2011. | DOI: 10.1177/0091270010385932

This study investigated possible effects of brimonidine tartrate 0.2% and apraclonidine 0.5% on pupil diameter. Ten subjects between 20 and 40 years of age participated. A Colvard pupillometer (Oasis Medical) was used to measure pupil diameter. Baseline and serial measurements were obtained at 3 luminance levels (>6.4, <0.82-0.4, and <0.2-0.02 cd/m) during a 4-hour interval following instillation of 1 drop of brimonidine tartrate 0.2% or apraclonidine 0.5% in one eye versus a placebo in the contralateral eye. The measurements for each drug were obtained on different days. A nested random effects model controlling for subject's age, race, and sex was used for statistical analysis. A maximum reduction in pupil diameter was observed at 90 minutes from instillation (1.40 mm at >6.4 cd/m, 1.69 mm at <0.82-0.4 cd/m, and 1.55 mm at <0.2-0.02 cd/m) for brimonidine tartrate 0.2%. At all time intervals and illumination levels, miosis (P < .01) occurred. Apraclonidine 0.5% did not produce a significant effect on pupil diameter. Brimonidine tartrate 0.2% produced a moderate miotic effect. No effect was observed for apraclonidine 0.5%. A predominant agonistic effect on α-2 receptors of the iris dilator may explain this behavior.