Band keratopathy is a corneal disease derived from the appearance of

calcium Calcium is a chemical element; it has symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar to it ...

on the central

cornea The cornea is the transparency (optics), transparent front part of the eyeball which covers the Iris (anatomy), iris, pupil, and Anterior chamber of eyeball, anterior chamber. Along with the anterior chamber and Lens (anatomy), lens, the cornea ...

. This is an example of metastatic

calcification Calcification is the accumulation of calcium salts in a body tissue. It normally occurs in the formation of bone, but calcium can be deposited abnormally in soft tissue,Miller, J. D. Cardiovascular calcification: Orbicular origins. ''Nature M ...

, which by definition, occurs in the presence of hypercalcemia.eMedicine
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Signs and symptoms

Signs and symptoms of band keratopathy include eye

pain Pain is a distressing feeling often caused by intense or damaging Stimulus (physiology), stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sense, sensory and emotional experience associated with, or res ...

and decreased

visual acuity Visual acuity (VA) commonly refers to the clarity of visual perception, vision, but technically rates an animal's ability to recognize small details with precision. Visual acuity depends on optical and neural factors. Optical factors of the eye ...

Causes

Band keratopathy has several causes. These causes include

uveitis Uveitis () is inflammation of the uvea, the pigmented layer of the eye between the inner retina and the outer fibrous layer composed of the sclera and cornea. The uvea consists of the middle layer of pigmented vascular structures of the eye and ...

, interstitial keratitis, superficial keratitis, phthisis,

sarcoidosis Sarcoidosis (; also known as Besnier–Boeck–Schaumann disease) is a disease involving abnormal collections of White blood cell, inflammatory cells that form lumps known as granulomata. The disease usually begins in the lungs, skin, or lymph n ...

, trauma, intraocular silicone oil, systemic diseases ( high levels of calcium in the blood, vitamin D intoxication, Fanconi's Syndrome, low levels of phosphorus in the blood,

gout Gout ( ) is a form of inflammatory arthritis characterized by recurrent attacks of pain in a red, tender, hot, and Joint effusion, swollen joint, caused by the deposition of needle-like crystals of uric acid known as monosodium urate crysta ...

milk-alkali syndrome Milk-alkali syndrome (MAS), also referred to as calcium-alkali syndrome, is the third most common cause of elevated blood calcium levels ( hypercalcemia). Milk-alkali syndrome is characterized by hypercalcemia, metabolic alkalosis, and acute ki ...

, myotonic dystrophy, and chronic mercury exposure).

Pathology

Band keratopathy is seen when there is

of the epithelial

basement membrane The basement membrane, also known as base membrane, is a thin, pliable sheet-like type of extracellular matrix that provides cell and tissue support and acts as a platform for complex signalling. The basement membrane sits between epithelial tis ...

, Bowman's layer, and the anterior stroma with destruction of Bowman's layer. The calcium salts are intracellular when the process is due to alteration of systemic calcium metabolism, whereas they are extracellular when due to local disease.

Diagnosis

Band keratopathy is diagnosed by

slit lamp In ophthalmology and optometry, a slit lamp is an instrument consisting of a high-intensity light source that can be focused to shine a thin sheet of light into the eye. It is used in conjunction with a biomicroscope. The lamp facilitates an ...

examination of the eye.

Treatment

Treatment is indicated if vision is threatened or if the eye is uncomfortable. It is important to recognize and treat any underlying condition. Improvement of vision may be obtained by scraping off the opacity. Topical disodium

EDTA Ethylenediaminetetraacetic acid (EDTA), also called EDTA acid, is an aminopolycarboxylic acid with the formula . This white, slightly water-soluble solid is widely used to bind to iron (Fe2+/Fe3+) and calcium ions (Ca2+), forming water-solubl ...

can be used as a

chelating agent Chelation () is a type of bonding of ions and their molecules to metal ions. It involves the formation or presence of two or more separate coordinate bonds between a polydentate (multiple bonded) ligand and a single central metal atom. These l ...

. It can also be removed with the excimer laser (phototherapeutic keratectomy). Other modalities include diamond burr and lamellar keratoplasty.

References

External links

Disorders of sclera and cornea {{Ophthalmology-stub}