Assessment of chamber angle pigmentation during longterm latanoprost treatment for open-angle glaucoma

This study aimed to determine whether the longterm use of latanoprost is associated with an increase in trabecular pigmentation, especially in subjects in whom iris pigmentation has increased.

We enrolled 50 subjects for whom treatment was to start for ocular hypertension, primary open-angle glaucoma or normal tension glaucoma. All subjects received latanoprost 0.005% daily. Trabecular pigmentation was documented using gonioscopic photography of the inferior quadrant at baseline, every 3 months for the first year and every 6 months for the second and third years. Three glaucoma specialists evaluated the series of gonioscopic photographs for each eye of each subject in a masked fashion. The intraocular pressure (IOP) was also recorded at each visit.

A total of 41 subjects (79 eyes) completed 3 years of follow-up, and none showed any increase in the grade of trabecular pigmentation, including 10 subjects (20 eyes) in whom the iridial pigment increased.

Although latanoprost increased iridial pigmentation in some subjects, we found no evidence of an increase in trabecular pigmentation over the 3 years of follow-up.