The efficacy of latanoprost is independent of the width of the ciliary body face.
OBJECTIVE
To assess the relation between the intraocular pressure-lowering efficacy of latanoprost 0.005% and the area of the ciliary body face exposed to the anterior chamber as assessed by ultrasound biomicroscopy.


METHODS
Untreated, latanoprost-naive patients with ocular hypertension or open-angle glaucoma were enrolled in this prospective clinical trial. A radial, perpendicular ultrasound biomicroscopy image at the 6-o'clock position detailing Schwalbe line, scleral spur, and iris insertion was obtained. The distances between these structures were then measured and their relations to the intraocular pressure-lowering effect of latanoprost at 1, 2, 3, and 6 months were analyzed.


RESULTS
Fifty-four eyes (54 patients) were enrolled. The mean age of participants was 60.2 +/- 13.9 years, and mean pretreatment intraocular pressure was 26.4 +/- 3.8 mm Hg. The mean intraocular pressure reduction from baseline was 7.1 mm Hg (26.9%), 7.3 (27.7%), 7.8 (29.5%), and 7.7 (29.2%) at 1, 2, 3 and 6 months, respectively. The mean distance between the scleral spur and the iris insertion was 0.14 +/- 0.08 mm (range, 0.04-0.33 mm). There was a significant correlation between intraocular pressure reduction at 1 month and trabecular meshwork height, suggesting that intraocular pressure reduction was associated with increasing trabecular meshwork height (P < 0.05). No other correlation could be found regarding intraocular pressure reduction.


CONCLUSIONS
Although latanoprost lowers intraocular pressure by enhancing uveoscleral outflow, its efficacy is independent of the height of the ciliary face.
Ritch
Robert
R
Department of Ophthalmology and the Biostatistics and Epidemiology Service, The New York Eye and Ear Infirmary, New York, New York and The New York Medical College, Valhalla, New York 10003, USA. ritch@inx.net
Ishikawa
Hiroshi
H
Rothman
Robert
R
Yu
Guopei
G
Liebmann
Jeffrey M
JM
D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001830:Body Surface Area; D002924:Ciliary Body / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005260:Female; D005902:Glaucoma, Open-Angle / Q000188:drug therapy*; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects*; D000077338:Latanoprost; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000188:drug therapy; D009883:Ophthalmic Solutions; D011446:Prospective Studies; D011461:Prostaglandins F, Synthetic / Q000008:administration & dosage / Q000627:therapeutic use*; D014463:Ultrasonography
D000959:Antihypertensive Agents; D009883:Ophthalmic Solutions; D011461:Prostaglandins F, Synthetic; D000077338:Latanoprost