Iris Cross Section

Iris and anterior chamber, light micrograph. The cornea, anterior chamber angle, trabecular meshwork, canal of Schlemm and part of the ciliary body are included. The anterior and posterior iris contraction furrows are accentuated by the slight dilatation of the pupil. The pupil and the pupillary ruff are at (a) and the iris root is at (b). The pupillary portion of the iris is at (c) and the ciliary portion at (d). The collarette (e) and minor arterial circle of the iris lie at the junction of these two portions. The cellular anterior border layer (f) is distinct from the very loosely arranged stromal tissue (g). The sphincter muscle lies in the stroma at (h).
The posterior iris shows a posterior (i) and anterior (j) epithelium; the latter forms the dilator muscle. The anterior chamber angle shows a part of a uveal band (k). The trabecular meshwork (l) and canal of Schlemm (m) lie external to the chamber angle. The ciliary body and its muscle are posterior to the iris (n). (X 60)