Ultrasound Biomicroscopic Study of Ciliary Body Thickness After Topical Application of Pharmacologic Agents

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.