Bullous Keratopathy - swelling (edema) and blistering of the CORNEA. Bullous keratopathy most commonly develops as a complication following CATARACT EXTRACTION AND LENS REPLACEMENT or other surgery on the EYE, though it also may develop as a consequence of chronic irritation such as might occur with DRY EYE SYNDROME.
The healthy cornea is about 75 percent water. One function of the cells that surround the cornea is to maintain this fluid balance. Irritation and trauma that damage these cells diminishes their ability to function, and the cornea retains more water. The swelling stretches the surface of the cornea, pushing the cornea into closer contact with the eyelid and resulting in further irritation. Bullae, or blisters, develop as the cornea’s attempt to relieve the discomfort, much as blisters develop on the feet or hands in reaction to friction.
Symptoms of Bullous Keratopathy and Treatment
Early symptoms of bullous keratopathy are a sensation of grittiness in the eye, blurred vision, excessive tearing, and PHOTOPHOBIA (sensitivity to light). When bullae form, and especially when they rupture, the PAIN often is severe. The ophthalmologist can diagnose bullous keratopathy using SLIT LAMP EXAMINATION of the cornea, a painless procedure that combines an intense light focused in a slit with magnification through a ophthalmologic microscope. Eye drops or ointment with a higher saline concentration than tears helps draw fluid out of the cornea, reducing the swelling. Soft contact lenses, which absorb fluid from the eye and shield the cornea from contact with the eyelid, relieve discomfort for many people. Bullous keratopathy tends to be chronic, and over time may result in damage to the cornea that requires the cornea’s surgical removal (keratotomy) or CORNEAL TRANSPLANTATION.