Схема. Строение радужки = Anatomy of iris. Перевести на русский язык = Translate into Russian Модификация: Stein H.A., Stein R.M., Freeman M.I. The Ophtalmic Assistant: A Text for Allied and Associated Ophtalmic Personnel. 8th ed., Elsevier, 2006, 877 p. см.: Физиология человека: Литература. Иллюстрации.

Примечание:

The iris normally is quite clear to inspection. The irides of both eyes are generally the same color. The color depends on the amount of pigment in the stroma and posterior layer of the iris. A heavily pigmented iris appears brown, whereas a lightly pigmented one appears blue. Interestingly enough, there is no blue pigment in the iris. In the blue iris, the light passes through the nonpigmented stroma and strikes the pigmented epithelial cells on the back of the iris so that light of longer wavelength (red) is absorbed and that of shorter wavelength (blue) is reflected. A difference in the color between the two irises (heterochromia) may be indicative of a congenital abnormality, iris tumor, retained intraocular foreign body (siderosis) or old iritis. If a light is brought to bear on the iris at close range against the sclera (transillumination), the light may seem to glow in a patchy way in areas where there has been marked pigment loss. This can occur with some forms of glaucoma (pigmentary), after iritis or with albinism. Freckles on the iris should be noted because iris freckles are frequently associated with intraocular malignant melanomas. Near the root of the iris lies the dilator muscle. When dilation occurs, at a maximum, the pupil may be 9mm or greater in diameter. When maximally contracted, it may be only 1mm. The iris is normally well supported by the underlying lens. Tremulousness of the iris (iridodonesis) usually means the presence of a dislocated lens. Tremulousness of the iris, or undulating movements of the iris structure, is best seen by having the patient look quickly from one point of fixation to another. Near the aperture is a sphincter muscle that constricts the pupil. In the center of the iris, running radially around the pupil and forming a circular web, are the blood vessels of the iris. If the lens is absent (aphakia), the iris loses its support, flattens and deepens the anterior chamber. It may become tremulous. A defect in the iris is called a coloboma. A coloboma, which indicates absence of some portion of the iris, may be the result of previous surgery or a congenital abnormality. Muddiness of the iris is a term used to express the general loss of clarity of the pattern of the iris. It is caused by inflammatory exudates in the anterior chamber or on its surface. Normally the textured surface of the iris and the white markings of the iris vessels are easily visible.