Band keratopathy is caused due to the calcium salts precipitation on the surface of the cornea (under the epithelium directly). Normal body fluids (such as aqueous humor or tears) and serum contain phosphate and calcium in concentrations which approach their solubility product. Tears evaporation tries to concentrate solutes and also increase the tears tonicity.
Elevated serum phosphate or serum calcium can provide support to the precipitation. Medications, especially topical medications which contain phosphate may also result in this problem. Finally, if the pH levels of the surface are elevated higher than the physiologic range, then the solubility product changes that favors precipitation. This article gives information about the causes of band keratopathy.
Causes of Band Keratopathy
The following are the causes associated with this condition:
Hypercalcemia (elevated levels of calcium in the blood) as a result of the following:
- Excessive intake of vitamin D
- Hyperparathyroidism – Excess parathyroid hormone production
Renal failure - Milk-alkali syndrome – Repeated ingestion of absorbable alkali and calcium.
- Hypophosphatasia – It is a fatal and rare metabolic bone disease.
- Sarcoidosis – The actual cause of this disease is not known and it leads to inflammation.
- Paget disease – This disorder results in excessive and rapid bone breakdown.
Other systemic conditions:
- Tuberous sclerosis — This condition results in growth of benign tumors in the brain, heart, kidneys, eyes, skin and lungs.
- Discoid lupus erythematosis — It is a chronic skin condition and is characterized by scarring type skin inflammation and inflammation
which occur on scalp, face and ears and sometimes on other areas of the body.
Local ocular conditions
- End-stage glaucoma
- Chronic uveitis — It can result in blurred vision and dull aches.
- Anterior mosaic dystrophy — This causes breaks in Bowman’s layer.
- Phthisis bulbi — It is a non-functional, shrunken eye which results from inflammation, severe ocular disease or injury.
- Juvenile idiopathic arthritis (persistent arthritis in children) along with uveitis.
Drug associated calcium deposition
Chemical fume related
- Calcium bichromate vapor
- Mercury vapor
- Intraocular use of rt-PA (recombinant tissue-plasminogen activator)
History of Band Keratopathy
Patients suffering from band keratopathy complain of the following:
- Foreign body sensation (feels that something is present in the eye)
- Decreased vision
- Redness (occasionally)
- Ocular irritation
