Fuchs endothelial dystrophy
Fuchs endothelial dystrophy is a condition affecting the cornea that leads to blurred vision, sensitivity to light, and potential eye pain.
Overview
Fuchs endothelial dystrophy affects the front surface of the eye, known as the cornea. The first symptom is typically blurred vision in the morning that clears during the day. Over time, individuals lose visual acuity and become sensitive to bright lights.
During an eye exam, deposits called guttae are detectable in the middle of the cornea. These eventually spread, contributing to cell death and corneal swelling. Tiny blisters may develop on the cornea, which can burst and cause eye pain. Symptoms usually begin in a person's forties or fifties, though a rare early-onset variant can affect vision in a person's twenties.
Frequency
The late-onset form affects approximately 4 percent of people over age 40 in the United States. The condition affects women two to four times more frequently than men.
Causes
Fuchs endothelial dystrophy involves the death of corneal endothelial cells, which line the back of the cornea and regulate fluid balance. When these cells die, the cornea becomes swollen with fluid, leading to vision problems.
While the genetics are complex, researchers have identified several genes that may play a role:
- COL8A2: Mutations in this gene cause some cases of the early-onset variant. This gene provides instructions for a protein that is part of type VIII collagen, a major component of Descemet's membrane, which supports corneal endothelial cells.
- TCF4, AGBL1, ATP1B1, KANK4, LAMC1, SLC4A11, and ZEB1: These genes are also associated with the condition.
Inheritance
The inheritance pattern is often unknown. In some families, it follows an autosomal dominant pattern, where one copy of the altered gene is sufficient to cause the disorder. Some cases result from new mutations in a gene and occur in people with no family history of the disorder.