Causes of Band Keratopathy
Band keratopathy is caused due to 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 increases 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 which 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 occurs 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.
Drugs associated calcium deposition
- Pilocarpine that contains mercury-based preservatives
- Steroid phosphate preparations
- Silicone oil
- Viscoelastic agents (improves visualization)
- Topical medications which contain phosphate buffers
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 like something is present in the eye)
- Decreased vision
- Redness (occasionally)
- Ocular irritation
Now, that you know the causes of band keratopathy, read our related article to learn about Band Keratopathy Treatment