ULTRASOUND BIOMICROSCOPIC STUDY OF CILIARY BODY THICKNESS AFTER TOPICAL APPLICATION OF PHARMACOLOGICAL AGENTS

PURPOSE: To examine the changes in ciliary body thickness after topica l application of pilocarpine, cyclopentolate hydrochloride, and PhXA41 , a prostaglandin F-2 alpha analog. METHOD: We used a high-frequency H umphrey YBM840 ultrasound biomicroscope to examine 36 healthy young Ja panese subjects. RESULTS: The mean ciliary body thickness increased fr om 0.67 +/- 0.07 mm to 0.73 +/- 0.08 mm (P < .01) after application of 2% pilocarpine; 1% cyclopentolate hydrochloride and 0.005% PhXA41 dec reased 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. CONCLUSIONS: Our ultrasound study dearly indicate d 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.