The color of the human eye: A review of morphologic correlates and of some conditions that affect iridial pigmentation

doi:10.1016/S0039-6257(97)80018-5

Survey of Ophthalmology

Volume 41, Supplement 2, February 1997, Pages S117-S123

https://doi.org/10.1016/S0039-6257(97)80018-5 Get rights and content

Abstract

Iris color can be affected by a variety of ocular disorders. It is suspected that iris color may not remain constant throughout life. These observations have drawn attention to the morphologic correlates of iris color and its regulation. Differences in the iris color of normal eyes are the result of variable amounts of melanin pigment granules within a constant number of melanocytes in the superficial stroma of the iris. These melanocytes seem to reach their genetically determined amount of melanin in early childhood, and their melanin content usually remains constant in adulthood. Diseases such as Horner's syndrome and Fuchs' heterochromic iridocyclitis affect iris color, resulting in a decrease of iris pigmentation. Evidence suggests that melanin content of some melanocytes is subject to adrenergic regulation even past childhood. Application of the prostaglandin analogue latanoprost, on the other hand, leads to an increase in iris pigmentation in some patients. Studies with cultured dermal and uveal melanocytes, as well as with uveal melanoma cells, however, show no increase in cell proliferation when treated with latanoprost in vitro. The mechanisms by which latanoprost affects regulation of iris pigmentation requires further investigation.

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Three hundred healthy, adult, white female patients were included, 133 with dark eyes and 167 with light eyes. Dental anxiety was assessed with the Corah Dental Anxiety Scale. Subjects with their eye color masked by dark glasses received a right maxillary lateral incisor infiltration of 1 cartridge of 2% lidocaine with 1:100,000 epinephrine. Patients rated their injection pain on a 170-mm Heft-Parker visual analog scale. Photographs of the subjects' eyes were taken after the infiltrations and categorized into dark- and light-eyed groups by 3 independent observers. Comparisons for injection pain were analyzed using analysis of variance and the Tukey-Kramer test.
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: This work was supported in part by Pharmacia Ophthalmics Inc. NEI EYO 1917 (Dr. Albert), the Swiss National Foundation (Dr. Imesch), an unrestricted gift to the Department of Ophthalmology and Visual Sciences from Research to Prevent Blindness, Inc., and the Wisconsin Lions Eye Research Fund.

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The color of the human eye: A review of morphologic correlates and of some conditions that affect iridial pigmentation

Abstract

Am J Ophthalmol

Ophthalmology

Am J Ophthalmol

Ophthalmology

Exp Eye Res

Am J Ophthalmol

Surv Ophthalmol

Am J Ophthalmol

Establishment of cell lines ofuveal melanoma, Methodology and characteristics

Invest Ophthalmol Vis Sci

Phase III latanoprost studies in Scandinavia, the United Kingdom and the United States

Surv Ophthalmol

Comparison of latanoprost and timolol in patients with ocular hypertension and glaucoma — Preliminary results of the USA multicenter trial

Changes in iridial pigmentation past childhood through adolescence (abstract)

Invest Ophthalmol Vis Sci

Heredity of eye-color in man

Science

Zur Feinstruktur der Melanocyten in dermenschlichen Iris

Albert v Graefes Arch Klin Exp Ophthalmol

Lack of adrenergic influence on the pigmentation of iris nevus cells

Arch Ophthalmol

The iris

Iris pigmentation and pigmented lesions, An ultrastructural study

Trans Am Ophthalmol Soc

Studies on human ocular pigment

Normal pigmentierte und albinotische Iris

Albrecht von Graefes Arch Klin Exp Ophthalmol

Über Kompliklationen der Heterochromie

Z Augenheilkd

Melanosomes

Race, iris pigmentation, and intraocular pressure

Am J Epidemiol