Ultrasound biomicroscopic study of ciliary body thickness after topical application of pharmacologic agents.

Abstract

To examine the changes in ciliary body thickness after topical application of pilocarpine, cyclopentolate hydrochloride, and PhXA41, a prostaglandin F2alpha analog. We used high-frequency Humphrey UBM840 ultrasound biomicroscope to examine 36 healthy young Japanese subjects. The mean ciliary body thickness increased from 0.67 +/- 0.07 mm to 0.073 +/- 0.08 mm (P < .01) after application of 2% pilocarpine; 1% cyclopentolate hydrochloride and 0.005% PhXA41 decreased the mean ciliary body thickness from 0.75 +/- 0.07 mm to 0.69 +/- 0.05 mm (P < .05) and from 0.78 +/- 0.06 mm to 0.75 +/- 0.06 mm (P < .01), respectively. Our ultrasound study clearly indicates that pilocarpine increased comparative thickness of the ciliary body by 8.3%, whereas PhXA41 decreased comparative thickness by 3.3% in a manner similar to cyclopentolate hydrochloride.