Cogan's Dystrophy (or Map-Dot-Fingerprint Dystrophy) is a disease affecting the cornea. It is characterized by microscopic dot and fingerprint-like patterns that form within the cornea.
The superficial layer of the cornea, also called the epithelium, is what is affected by Cogan's Dystrophy. The epithelium's bottom cells become thickened and uneven, which weakens the cell bonds and may cause the epithelium to loosen and "slough off" in areas, a condition called corneal erosion.
How do I get it?
Cogan's is not genetic so it isn't inherited. It typically affects both eyes and is diagnosed after the age of 30. Cogan's usually becomes progressively worse with age.
What are the Symptoms?
Cogan's is often silent and therefore, there may be no symptoms. The symptoms among patients may vary widely in severity and include:
Mild to extreme irritation and discomfort that is worse in the morning
Irregular astigmatism (uneven corneal surface)
The doctor may detect the disease by examining the layers of the cornea with a slit lamp microscope.
How is it treated?
The treatment for Cogan's depends on the severity of the problem. In some cases, corneal topography may be needed to evaluate and monitor astigmatism resulting from the disease. Artificial tears are used to lubricate the cornea and keep the surface smooth and comfortable. Lubricating ointments may be used at bedtime so the eyes are more comfortable in the morning. Saline solution drops or ointments are often prescribed to reduce swelling and improve vision. Gas permeable contacts may be fit for patients with irregular astigmatism to create a smooth, even corneal surface and improve vision.
For patients with recurrent corneal erosion, a soft contact lens may be used as a bandage to keep the eye comfortable and allow the cornea to heal. In some cases, laser treatment may beneficial. The surgeon removes the epithelium with an Excimer laser, creating a regular, smooth surface. The epithelium quickly regenerates, usually within a matter of days, forming a better bond with the underlying cell layer.