Bullous keratopathy can occur after cataract surgery (pseudophakic or aphakic bullous keratopathy) or after other forms of intraocular surgery. It may also occur in endothelial dystrophies such as Fuchs endothelial corneal dystrophy. Bullous keratopathy is a result of widespread endothelial cell loss or dysfunction. Corneal deturgescence cannot be maintained with insufficient endothelial cell function.
Clinically, bullous keratopathy is characterized initially by stromal edema and resulting folds in Descemet membrane, followed by intracellular epithelial edema (hydropic degeneration) and, ultimately, separation of the epithelium from the Bowman layer. Small separations called microcysts may coalesce to form large separations, known as bullae. In advanced cases of bullous keratopathy, secondary epithelial basement membrane changes, loss of stromal keratocytes, and pannus may occur (Fig 6-13).
Figure 6-12 Corneal pannus. A, Clinical photograph of pannus in the superior cornea. B, Fibrovascular degenerative pannus (area between arrows) is interposed between the epithelium and Bowman layer.
(Part A courtesy of George J. Harocopos, MD.)
Figure 6-13 Pseudophakic bullous keratopathy. A, Clinical photograph showing severe bullous keratopathy associated with an iris clip anterior chamber lens implant. B, Corneal button from penetrating keratoplasty. Note the subepithelial bullae (arrows). Also note stromal edema, characterized by focal absence of interlamellar clefts, and diffuse endothelial cell loss without thickening of Descemet membrane or guttae.
(Part A courtesy of Andrew J.W. Huang, MD; part B courtesy of George J. Harocopos, MD.)
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.