Corneal dystrophy, microcystic: A disorder in which the cornea (the normally clear front window of the eye) shows dots (or microcysts), geographic map-like lines, and grayish fingerprint lines on examination with a slit-lamp, a device that focuses a high intensity light beam as a slit while the examiner looks at the front of the eye through a magnifying scope.
The disorder is usually silent and without symptoms. However, about one patient in ten has recurrent erosion of the cornea that usually begins after the age 30.
Conversely, half of patients with recurrent corneal erosions of idiopathic (unknown) origin have this disorder.
Under the microscope, a structure called the epithelial basement membrane is abnormal. The disorder is therefore sometimes called epithelial basement corneal dystrophy.
The disorder was first described by Cogan and colleagues in 1964. Hence, the name: Cogan corneal dystrophy. It is also known, to add to the confusion, as map-dot-fingerprint type corneal dystrophy.
- Corneal ring, intrastromal
Corneal ring, intrastromal: A plastic ring designed to be implanted in the cornea in order to flatten the cornea and thereby correct, or reduce the degree of, nearsightedness (myopia). The ring is placed in the corneal stroma, the middle of the five layers of the cornea.
- Corneal topography
Corneal topography: Also known as videokeratography or corneal mapping, corneal topography is a method of computer-assisted examination of the cornea, the clear front portion of the eye that transmits and focuses light into the eye. Corneal topography is performed by projecting illuminated rings onto the corneal surface which are reflected back and measured by the […]
- Corneal transplant
Corneal transplant: Replacement of a portion of the clear window on the front of the eye (cornea) with a healthy cornea. The procedure is typically done under local anesthesia in an outpatient setting. Transplantation of the cornea may be indicated in cases of severe scarring of the cornea by injury or infection (as with corneal […]
Small calloused areas of skin caused by local pressure irritating tissue over a bony prominence. Corns most commonly occur over a toe where they form what is referred to as a hard corn. Between the toes, pressure can form a soft corn of macerated skin which often yellows. The word corn comes from the Latin […]
Coronal: A coronal plane through the body is a vertical plane from head to foot and parallel to the shoulders.