Effect of Age on the Development of a Latanoprost-Induced Increase in Iris Pigmentation

PurposeTo study the effect of patient age on the incidence of latanoprost-induced increases in iris pigmentation.DesignProspective observational observer-masked study.ParticipantsThirty-six patients younger than 60 years (group 1) and 36 patients older than 75 years (group 2) with primary open-angle glaucoma.MethodsWe photographed both irises of each patient before and 6 months after unilateral latanoprost therapy. The basal iris colors were matched in both groups.Main Outcome MeasuresIris heterochromia identification at the 6-month evaluation of the photographs.ResultsTwenty-eight patients (77.78%) in group 2 developed an increase in iris pigmentation compared with eight patients (22.22%) in group 1 (P = 0.0001, chi-square test).ConclusionsAge seems to be an important risk factor for latanoprost-induced iris color change.