The aim of this study was to evaluate the efficacy of 0.005% latanoprost in lowering intraocular pressure (IOP) in patients with chronic angle-closure glaucoma (CACG) and no visible ciliary-body face. Fourteen eyes of 14 Korean patients with CACG with 360 degrees of peripheral anterior synechiae (PAS) and an IOP greater than 21 mmHg without medication were treated with 0.005% latanoprost once-daily. All patients completed 3 months of treatment with latanoprost. The IOP, which was 30.3 +/- 4.5 (mean +/- standard deviation) mmHg at baseline, decreased to 22.6 +/- 4.9 mmHg after 1 week, 19.6 +/- 5.5 mmHg after 1 month, 19.4 +/- 4.9 mmHg after 2 months, and 21.5 +/- 5.9 mmHg after 3 months of treatment with latanoprost (P < 0.01 for each). Ultrasound biomicroscopy of the anterior chamber angle showed anterior bowing of the iris with total occlusion of the angle by PAS, except for 5 eyes with focal microscopic openings to the ciliary-body face at various angles. Adverse ocular events were well-tolerated and transient. In this preliminary study, treatment with 0.005% latanoprost once-daily resulted in a significant reduction in IOP in CACG patients with 360 degrees of PAS on gonioscopy. Our results suggest that latanoprost may be considered as a therapy of choice in these rare cases.