Evidence of early change in iris color with latanoprost use.

Latanoprost, a 17-phenyl–substi-tuted analog of PGF 2 ␣, has been shown to effectively lower intraocu-lar pressure in clinical trials and darken the irides in both subhuman primates and humans. 1 The reported time of onset of the change in iris color has been noted to be as early as 3 months. To our knowledge , this case represents the earliest reported change in iris color following the initiation of latano-prost use. Report of a Case. A 78-year-old white woman was first seen in 1986 complaining of worsening vision, which was found to be secondary to nuclear sclerosis involving her right eye. She underwent an uncomplicated extracapsular cataract extraction with intraocular lens implan-tation in December 1988. Prior to surgery, she had intraocular pressure in the midteens and small symmetric cups with healthy neuroreti-nal rims. In 1992, she had elevated intraocular pressure in the right eye in the high 20s to low 30s. On visual field testing, she demonstrated a nasal step. The patient was then given timolol maleate twice daily in the right eye. Her intraocular pressure was maintained in the high teens to low 20s using this treatment regimen until she was seen in 1993 with evidence of progression of her visual field defect. In 1994, the medical therapy was changed to 1% pilocarpine hydrochloride 4 times daily. During a 3-year period, the op-tic nerve of her right eye progressed with evidence of vertical elongation and a superior rim defect. In 1996, after a course of dor-zolamide hydrochloride was given in the right eye 3 times daily with minimum improvement, the patient was then given latanoprost in the right eye only for a 4-week period. The iris color in the right eye was the same as the left eye at that time. During the 4-week period, the patient's iris color changed from blue-green to brown-green. Use of the medication was subsequently discontinued (Figure). Comment. Alm et al 1 summarized the results of 198 patients who previously participated in the original phase 3 clinical trials that assessed the safety and efficacy of latano-prost. Photographs of the iris were not taken prior to 2 months after the initiation of treatment. Darkening of the iris occurred in 14 patients (7%) at 6 months and in 24 patients (12%) after 1 year of treatment. The authors noted that nevi or freckles did not increase in size and the likelihood of change was greatest in …