Rubeosis iridis, or neovascularization of the iris (Fig 12-12; see also Chapter 11, Fig 11-28), is commonly found in surgically enucleated blind eyes. It is often due to severe inflammation or production of vascular endothelial growth factor in the eye. Rubeosis iridis may be associated with a wide variety of conditions (see BCSC Section 10, Glaucoma, Table 10-2).
Histologically, the new vessels tend to lack supporting tissue and do not possess the thick collagenous cuff that encircles normal iris vessels. The new vessels grow on the anterior surface of the iris, eventually forming a fibrovascular membrane, and may extend into the anterior chamber angle. The neovascular membrane has a myofibroblastic component, which contracts and eventually leads to angle closure due to formation of peripheral anterior synechiae. Neovascularization of the angle often results in neovascular glaucoma, a secondary form of angle-closure glaucoma. Membrane contraction may also lead to ectropion uveae, an anterior displacement or dragging of the posterior iris pigment epithelial layer onto the anterior iris surface at the pupillary border. The anterior surface of the iris often becomes flattened. In advanced cases, atrophy of the dilator muscle, attenuation of the pigment epithelium, and stromal fibrosis may occur (see Fig 12-12).
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.