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42 Clinical Anatomy of the Visual System

In pigmentary dispersion syndrome, pigment granules are shed from the posterior iris surface and are dispersed into the anterior chamber. They can be deposited on the iris, iens, or corneal endotheiium or in the trabecuiar meshwork, where they might compromise aąueous outflow.⁴ Significant pigment loss will be evident on transillumination of the iris when the red fundus refiex shows through in the depigmented areas.

Heterochromia of the iris is a condition in which ore rs differs in color from the other or portions of one iris a - i color from the rest of the iris. This can be either conge- ta ; o sign of uveal inflammation. If congenital, a disrupt or et the sympathetic innervation may be suspectedr A hiszz -i regarding iris coioration should be elicited.

the same reason that the sky is blue; the wavelength seen results from light scatter caused by the arrange-ment and density of the connective tissue components. Other colors are caused by the amount of light absorption, which depends on the pigment density within the melanocytes. If the iris is heavily pigmented, the anterior surface appears brown and smooth, even velvety, whereas in a lighter iris, the collagen trabeculae are evident and the color ranges from grays to blues to greens depending on the density of pigment and collagen. A freckle or a nevus is an area of hyperpigmentation, an accumulation of melanocytes, and freąuently is seen in the anterior border layer. In all colored irises, the two epithelial layers are heavily pigmented. Only in the albino iris do the epithelial layers lack pigment.³

Clinical Comment: Pigmentary Dispersion Syndrome

Clinical Comment: Heterochroml\

C I LI ARY BODY

When viewed from the front of the eye, the dliary b: is a ring-shaped structure. Its width is approsir:

5.9 mm on the nasal side and 6.7 mm on the temp :: side.² The posterior area of the dliary body termi n ates at the ora serrata, appears fairly fiat, but li anterior dliary body contains numerous fola: processes that extend into the posterior chamber sagittal section the dliary body has a triangular sha; the base of which is located anteriorly; one comer of il base lies at the ścierał spur, the iris root extends fr: the approximate center of the base, and a portion of rl base borders the anterior chamber. The outer side the triangle lies against the selera, and the inner :.. lines the posterior chamber and a smali portion c f tł vitreous cavity (Figurę 3-10). The apex is located at il ora serrata.

Nonpigmented

epithelium"

Ciliary

muscle

Ciliary

stroma

Supraciliaris

Pigmented epithelium '

/z;

Pars plicata

Pars piana

FIGURĘ 3-10

Partitions and layers of ciliary body.