Two Layers of the Iris
Cross section, brown iris. Contraction furrow (center) grooves loosely textured, collagen-rich iris stroma. Density of stromal cells is markedly increased in avascular anterior border layer zone. Scattered cells and thick-walled vessels, examined under high power in Fig. 3, are seen in deeper layers of stroma. Circumferential folds scallop posterior surface of iris pigment epithelium, which contains myriad round pigment granules. The dilatator muscle forms a thin band at stromal-epithelial junction (SEM, X 160).
