Corneal map-dot-fingerprint dystrophy is the most common corneal dystrophy, and occurs when the epithelium's basement membrane develops abnormally and the epithelial cells cannot properly adhere to it. This abnormality leads to recurrent epithelial erosions.
Epithelial erosions can be a chronic problem and may alter the normal curvature of the cornea causing blurred vision from time to time. The nerve endings lining the tissue may also be exposed and result in varying degrees of pain that can last a few days. The pain is generally found to be worse on waking in the morning. Symptoms include excessive tearing, feeling of foreign matter in the eye and sensitivity to light.
Map-dot-fingerprint dystrophy usually occurs in both eyes and affects adults between the ages of 40 and 70. The condition is slightly more common in females and usually not found in children.
The name derives from the affected epithelium having a map-like appearance: large, slightly grey outlines that look like a continent on a map. Sometimes concentric lines form in the central cornea that resemble small fingerprints.
The disease usually erupts for a few years and then goes away, with no lasting vision loss. As a rule, patients aren't aware they have map-dot-fingerprint dystrophy because there is no pain or vision loss. But if treatment is needed, ophthalmologists will focus on controlling the pain associated with the epithelial erosions. An eye patch is often used to immobilize the eye, together with prescription lubricating eye drops and ointments. These erosions can heal within three days although occasional pain may occur for several weeks thereafter.
Other treatments can include anterior corneal punctures and corneal scraping to remove eroded areas of the cornea to allow healthy tissue to regenerate. An excimer laser may be used to remove surface irregularities.