2020–2021 BCSC Basic and Clinical Science Course™
4 Ophthalmic Pathology and Intraocular Tumors
Part I: Ophthalmic Pathology
Chapter 10: Vitreous
A constellation of pathologic features may develop in the vitreous following vitreous hemorrhage. After 3–10 days, red blood cell clots undergo fibrinolysis, and red blood cells may diffuse throughout the vitreous cavity. At this time, red blood cell breakdown may also occur. Denaturation of hemoglobin in the red blood cells produces ghost cells (see Chapter 7, Fig 7-12) and hemoglobin spherules. Obstruction of the trabecular meshwork by these cells may lead to ghost cell glaucoma. See also BCSC Section 10, Glaucoma.
Figure 10-10 Macular holes. A, Spectral-domain optical coherence tomography (SD-OCT) image showing a stage 3 macular hole with full-thickness retinal defect, rounded margins, cystoid macular edema (asterisks), and an operculum (arrowhead). Note the posterior hyaloid face (arrow) tethered to the peripapillary retina near the optic nerve head. B, Gross photograph demonstrating a full-thickness macular hole (arrow).C, Photomicrograph of the edge of a full-thickness macular hole showing a rounded gliotic margin (arrow) with positive brown staining for glial fibrillary acidic protein (GFAP), highlighting the Müller cells and fibrous astrocytes.
(Part A courtesy of Robert H. Rosa Jr, MD; parts B and C courtesy of Patricia Chévez-Barrios, MD.)
The process of red blood cell dissolution attracts histiocytes, which phagocytose the degenerate red blood cells. Ferric iron (Fe3+) is released during hemoglobin breakdown. This can occur intracellularly in histiocytes with iron storage as ferritin or hemosiderin, or extracellularly with iron binding to vitreous proteins such as lactoferrin and transferrin. In massive hemorrhages, cholesterol may deposit in the vitreous in the form of cholesterol crystals, which result from the breakdown of red blood cell membranes. Clinically, cholesterol appears as refractile crystals in the vitreous cavity (synchysis scintillans); the crystals are typically not attached to vitreous fibrils. Syneresis of the vitreous and PVD are common after vitreous hemorrhage.
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.