Sixty-one infants were divided into three groups in a blinded crossover trial, and each group received one of three eyedrops (cyclopentolate, phenylephrine, or tropicamide) for the purpose of dilating the pupil for an exam. Each infant was seen on two different occasions and were either given a standard dose (drop volume were: cyclopentolate- 39.2 mcL, phenylephrine- 33 mcL, tropicamide- 33.8 mcL), or a microdrop (drop volume were: cyclopentolate- 6.5 mcL, phenylephrine- 5.1 mcL, tropicamide- 5.4 mcL). Pupil size, blood pressure and heart rate were measured were measured at regular intervals up to 60 minutes after drop application. Which agents caused significant changes in the measured parameters?
Mean blood pressure elevated in all patients receiving standard dosing of all three agents, none of the groups receiving microdrops had a statistically significant change. Heart rate did not change significantly between groups. Tropicamide microdrops resulted in a statistically significant difference in pupil size (inadequate dilation), but in the cyclopentolate and phenylephrine groups, pupil size was not significantly different in those with microdrops.
Elibol O, Alçe T, Yüksel N, Çaĝlar Y. The influence of drop size of cyclopentolate, phenylephrine and tropicamide on pupil dilatation and systemic side effects in infants. Acta Ophthalmologica Scandinavica. 1997 Apr;75(2):178-80.
Contributed by Kristine Nanagas, MD