Band keratopathy is a

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

derived from the appearance of

calcium Calcium is a chemical element with the 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 ...

on the central

cornea The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical power ...

. This is an example of metastatic calcification, which by definition, occurs in the presence of

hypercalcemia Hypercalcemia, also spelled hypercalcaemia, is a high calcium (Ca2+) level in the blood serum. The normal range is 2.1–2.6 mmol/L (8.8–10.7 mg/dL, 4.3–5.2 mEq/L), with levels greater than 2.6 mmol/L defined as hypercalcemi ...

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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 stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with, or resembling that associated with, ...

and decreased

visual acuity Visual acuity (VA) commonly refers to the clarity of vision, but technically rates an examinee's ability to recognize small details with precision. Visual acuity is dependent on optical and neural factors, i.e. (1) the sharpness of the retinal ...

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 Interstitial keratitis (IK) is corneal scarring due to chronic inflammation of the corneal stroma. Interstitial means space between cells i.e. corneal stroma which lies between the epithelium and the endothelium. Keratitis means corneal inflammat ...

, superficial keratitis,

phthisis Phthisis may refer to: Mythology * Phthisis (mythology), Classical/Greco-Roman personification of rot, decay and putrefaction Medical terms * Phthisis bulbi, shrunken, nonfunctional eye * Phthisis miliaris, miliary tuberculosis * Phthisis pulmo ...

sarcoidosis Sarcoidosis (also known as ''Besnier-Boeck-Schaumann disease'') is a disease involving abnormal collections of inflammatory cells that form lumps known as granulomata. The disease usually begins in the lungs, skin, or lymph nodes. Less commonly af ...

, trauma, intraocular silicone oil, systemic diseases ( high levels of calcium in the blood, vitamin D intoxication,

Fanconi's Syndrome Fanconi syndrome or Fanconi's syndrome (, ) is a syndrome of inadequate reabsorption in the proximal renal tubules of the kidney. The syndrome can be caused by various underlying congenital or acquired diseases, by toxicity (for example, from toxi ...

, low levels of phosphorus in the blood,

gout Gout ( ) is a form of inflammatory arthritis characterized by recurrent attacks of a red, tender, hot and swollen joint, caused by deposition of monosodium urate monohydrate crystals. Pain typically comes on rapidly, reaching maximal intensit ...

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

myotonic dystrophy Myotonic dystrophy (DM) is a type of muscular dystrophy, a group of genetic disorders that cause progressive muscle loss and weakness. In DM, muscles are often unable to relax after contraction. Other manifestations may include cataracts, intel ...

, and chronic mercury exposure).

Pathology

Band keratopathy is seen when there is

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 Mat ...

of the

epithelia Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ...

basement membrane The basement 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 Epithelium, epithelial tissues including mesot ...

Bowman's membrane The Bowman layer (Bowman's membrane, anterior limiting lamina, anterior elastic lamina) is a smooth, acellular, nonregenerating layer, located between the superficial epithelium and the stroma in the cornea of the eye. It is composed of strong, ...

, and the anterior stroma with destruction of Bowman's membrane. 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 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 anterior segm ...

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) is an aminopolycarboxylic acid with the formula H2N(CH2CO2H)2sub>2. This white, water-soluble solid is widely used to bind to iron (Fe2+/Fe3+) and calcium ions (Ca2+), forming water-soluble complexes eve ...

can be used as a

chelating agent Chelation is a type of bonding of ions and 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 ligands are ...

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

References

External links

{{Eye pathology Disorders of sclera and cornea