Band keratopathy is a disorder that affects the cornea, the clear dome-like structure on the front part of the eye. Band keratopathy is characterized by a linear band of calcium that becomes deposited across the cornea.

The deposition appears grainy and whitish-gray in color and looks a little like swiss-cheese. The calcium becomes deposited in the cornea between the area that is open and exposed between the eyelids when the eye is in an open position.

Causes

Band keratopathy is thought to be caused from conditions that increase the levels of calcium in the body such as kidney disease, excessive vitamin D, increased levels of certain thyroid hormones, sarcoidosis, lupus and Paget’s disease, a condition where there is an excessive breakdown of your bones.

Tears contain small amounts of calcium. Normal evaporation of your tears causes the calcium concentration to rise. This occurs more in the part of the cornea that is open to the atmosphere. However, when the tears have a much higher than normal level of calcium, this occurs at a very high rate. Because of this abnormal composition of the tears, the acidity level of the tears changes causes the process to occur even quicker, resulting in band keratopathy. Certain medical conditions mentioned above that cause calcium to rise in the body can cause this to occur. However, calcium can also build up in the tears with eye conditions that cause chronic inflammation. Also, people with conditions that cause swelling of the cornea or decompensation of the corneal cells have been known to develop band keratopathy.

Eye conditions that cause chronic inflammation can also cause band keratopathy to develop:

Long-term or end-stage glaucoma
Chronic iritis (uveitis)
Corneal dystrophies
Phthisis bulbi (a shrunken, non-functioning eye from severe disease or trauma)
Juvenile arthritis

One can also be exposed to certain outside foreign substances that can, over time, cause band keratopathy. Chronic exposure to mercury vapors has been known to cause band keratopathy. Also, preservatives that have a mercury type base have been found in some ophthalmic medication.

Symptoms

The calcium deposits can be fairly thick. Occasionally, they can break off and cause pain and scratches on the surface of the eye. Other symptoms are:

Blurred or decreased vision
Sandy or gritty sensation in the eye
Redness
Irritation

Treatment

Band keratopathy treatment consists of a chemical treatment called chelation. Chelation is a chemical process that uses EDTA (ethylenediamine-tetraacetic acid) that chemically removes the calcium from the cornea. After chelation, often an excimer laser, similar to the one used for LASIK, is used to remove any remaining calcium and to smooth the surface out.

After the procedure, either an amniotic membrane or a bandage soft contact lens is applied to the eye for a couple of weeks. Blood tests may need to be performed to determine the exact cause of the band keratopathy or it will reoccur.