Objective To assess whether iris color and eyelash changes occur with the use of unoprostone for2years.Design The 2clinical trials described herein we re prospective,random-ized,double-masked,active-contr olled,parallel group,multicenter studies.Participants A total of 1131patients with primary open-angle glaucoma or ocular hypertension participated in 2clinical trials an d received either uno-prostone isopropyl 0.15%(659),timolol maleate 0.5%(331),or betaxolol hydrochloride 0.5%(141),1drop per eye twice daily for up to 24months.Methods Color photographs(1:1magnification)were taken of the iris andeyelid of each patient at baseline an d at regular intervals thereafter through month 24using a s tandardized camera system.Photography included 7view s of each eye plus a calibration photograph and a patien t identification photo-graph,for a total of 16photographs p er patient per visit.Two independent (masked)readers subjectively compared baseline iris colors to subsequent v isits.Side view pho-tographs of the upper and lower eyela shes were used for the eyelash length analysis,with each h aving sufficient depth of field and a sufficient number of eyelashes in focus.Similarly,frontal eyelash views we re used for the eyelash density analysis.Main outcome measures Changes from baseline in iris color and eyelash le ngth and density within and between treatment groups.Resul ts Seven cases of iris color change(1.06%)were confirmed in patients treated with unoprostone for up to 24months;no confirmed cases were reported in the timolol or betax olol groups.In the unoprostone group,cases of iris color change were con-firmed at months 12(1case),18(2cases),and 24(4cases).No clinically relevant differences were observed among treatment groups for changes f rom baseline in eye-lash length or density.Conclusion A lthough iris hyper pigmentation and abnormal eyelash c hanges may occur after treatment with unoprostone,the incidence of these events appears to be low in the 2-year clinic al study. Objective To assess whether iris color and eyelash changes occur with the use of unoprostone for 2 years. Design The 2clinical trials described herein we re prospective, random-ized, double-masked, active-contr olled, parallel group, multicenter studies. Participants A total of 1131patients with primary open-angle glaucoma or ocular hypertension participated in 2 clinical trials an d received either uno-prostone isopropyl 0.15% (659), timolol maleate 0.5% (331), or betaxolol hydrochloride 0.5% (141) for up to 24months.Methods Color photographs (1: 1 magnification) were taken of the iris andeyelid of each patient at baseline an d at regular intervals thereafter through month 24 using as tandardized camera system. Photograph included 7view s of each eye plus a calibration photograph and a patien t identification photo-graph, for a total of 16 photographs p er patient per visit. Two independent (masked) readers subjectively compared baseline iris colors to subsequent v isits. Side view pho-tographs of the upper and lower eyela shes were used for the eyelash length analysis, with each h aving sufficient depth of field and a sufficient number of eyelashes in focus. Similarly, frontal eyelash views we re used for the eyelash density analysis. Main outcome measures Changes from baseline in iris color and eyelash le ngth and density within and between treatment groups. Res ts ts cases of iris color change (1.06%) were confirmed in patients treated with unoprostone for up to 24months; no confirmed cases were reported in the timolol or betax olol groups. the unoprostone group, the cases of iris color change were con-firmed at months 12 (1case), 18 (2cases), and 24 (4cases). No clinically relevant differences were observed among treatment groups for changes f rom baseline in eye-lash length or density. Conclusion A lthough iris hyper pigmentation and abnormal eyelash c hanges may occur after treatment with unoprostone, the incidence of these events appears to be low in the 2-year clinic al study.