In most circumstances, wounds of the iris do not stimulate a healing response in either the stroma or the epithelium. Though richly endowed with blood vessels and fibroblasts, the iris stroma does not produce granulation tissue to close a defect. In some circumstances, the pigmented epithelium may be stimulated to migrate, but that migration is usually limited to the subjacent surface of the lens capsule, where subsequent adhesion of epithelial cells occurs (posterior synechia). When fibrovascular tissue forms, it usually does so on the anterior surface of the iris as a neovascular membrane that may cover iridectomy or pupillary openings. This fibrovascular tissue may arise from the iris, the anterior chamber angle, or the peripheral cornea. Lack of wound healing in the iris is exploited when iridotomies, both surgical and laser, are performed.
The stroma and melanocytes of the ciliary body and choroid do not regenerate after injury. Histiocytes remove debris, and a thin fibrous scar, which appears white and atrophic clinically, develops.
Excerpted from BCSC 2020-2021 series: Section 4 - Ophthalmic Pathology and Intraocular Tumors. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.