Bullous Keratopathy

Bullous Keratopathy

Definition

Opacification of the cornea with epithelial bullae due to loss of function of the endothelial cells.

Epidemiology:

Bullous keratopathy is among the most frequent indicationsfor corneal transplants.

Etiology:

The transparency of the cornea largely depends on a functioningendothelium with a high density of endothelial cells (see Transparency). Where the endothelium has been severely damaged by inflammation, trauma, or major surgery in the anterior eye, the few remaining endothelial cells will be unable to prevent aqueous humor from entering the cornea. This results in hydration of the cornea with stromal edema and epithelial bullae (see Figs. 5.13a and b). Loss of endothelial cells may also have genetic causes (see Fuchs’ endothelial dystrophy).

Symptoms:

The gradual loss of endothelial cells causesslow deterioration ofvision. The patient typically will have poorer vision in the morning than in theevening, as corneal swelling is greater during the night with the eyelids closed.

Diagnostic considerations:

Slit lamp examination will reveal thickening ofthe cornea, epithelial edema, and epithelial bullae.

Differential diagnosis:

Bullous keratopathy can also occur with glaucoma.

However, in these cases the intraocular pressure is typically increased.

Treatment:

Where the damage to the endothelial cells is not too far advancedand only occasional periods of opacification occur (such as in the morning), hyperosmolar solutions such as 5% Adsorbonac can improve the patient’s eye-sight by removing water. However, this is generally only a temporary solu-tion. Beyond a certain stage a corneal transplant (penetrating keratoplasty;) is indicated.