PubMed ID: 18474771
Author(s): Albert DM, Gangnon RE, Grossniklaus HE, Green WR, Darjatmoko S, Kulkarni AD. A study of histopathological features of latanoprost-treated irides with or without darkening compared with non-latanoprost-treated irides. Arch Ophthalmol. 2008 May;126(5):626-31. doi: 10.1001/archopht.126.5.626. Erratum in: Arch Ophthalmol. 2008 Oct;126(10):1403. PMID 18474771
Journal: Archives Of Ophthalmology (Chicago, Ill. : 1960), Volume 126, Issue 5, May 2008
OBJECTIVES To study the histopathological features of latanoprost-treated irides with or without darkening, compared with non-latanoprost-treated irides.
METHODS Iridectomy specimens and patient history forms were independently examined by 3 ophthalmic pathologists in a masked fashion. Specimens were evaluated for premalignant changes and for differences in level of pigmentation and degrees of cellularity, inflammation, and vascular abnormalities.
RESULTS The specimens consisted of 22 latanoprost-treated darkened irides, 35 latanoprost-treated irides without darkening, and 35 non-latanoprost-treated irides. There was a statistically significant decrease in the number of nuclear invaginations and prominent nucleoli in latanoprost-treated darkened irides compared with the other 2 groups (P = .004 and P = .005, respectively). The average thickness and pigmentation of the anterior border layer was greater in the latanoprost-treated darkened irides than in the other 2 groups (P = .03 and P = .02, respectively). The latanoprost-treated darkened irides had increased pigmentation of the stroma (P < .001), stromal fibroblasts (P < .001), melanocytes (P = .005), vascular endothelium (P = .02), and adventitia (P < .001) relative to the other 2 groups.
CONCLUSIONS There is no histopathological evidence of premalignant changes in latanoprost-treated darkened irides. The latanoprost-induced iris color changes are due to a thickening of the anterior border layer and an increased amount of melanin in the anterior border layer and within the stromal melanocytes.