Fuchs endothelial dystrophy of the cornea is a characteristic posterior corneal dystrophy. It is marked by progressive damage to the corneal endothelium, eventually leading to endothelial decompensation. It follows an autosomal dominant inheritance pattern and is possibly caused by mutations in the COL8A2 gene encoding type VIII collagen, located in the 1p34.3-p32 region of the short arm of chromosome 1.
Pathological analysis reveals focal thickening of the posterior limiting lamina of the cornea, forming corneal guttae that project toward the anterior chamber. The endothelial cells overlying the tips of the guttae become thinner, and the overall endothelial cell density decreases. Hematoxylin and eosin (HE) staining and periodic acid–Schiff (PAS) staining can reveal mushroom-shaped, hemispherical, or flat anvil-like contours of the corneal guttae.
Clinical Manifestations
This condition is more commonly observed in postmenopausal women, with symptoms often appearing after the age of 50 and gradually worsening. It is typically bilateral. In the early stages, when disease is limited to the endothelium and posterior limiting lamina, no subjective symptoms are present. The posterior limiting lamina develops guttae, which push the endothelium outward into the anterior chamber. Diffuse thickening of the posterior limiting lamina may occur, and endothelial pigmentation is sometimes observed. When endothelial decompensation occurs, stromal and epithelial edema develops, leading to subjective symptoms such as visual decline, halos around lights, and blurred vision. Progression to bullous keratopathy causes symptoms such as pain, photophobia, and tearing.
Treatment
Early-stage patients without symptoms do not require treatment. For intermittent corneal edema, hypertonic agents and medications aimed at protecting and nourishing the cornea may be attempted. For severe corneal edema and cases of endothelial decompensation, treatment approaches are referenced similarly to those for bullous keratopathy.