- Clinical features:
- Symptoms:
- Decrease visual acuity as the deposits become white and
dense
- Painful
- Signs:
- Interpalpebral deposition of calcium phosphate salts in
the subepithelial and anterior stroma with clear areas separating
it from the limbus
- Clear areas and small circular areas where nerve endings
perforate the Bowman's layer are seen within the band and
give it a "Swiss cheese" appearance
- Identifiable causes: dry eye syndrome, chronic exposure keratopathy,
chronic ocular inflammation such as uveitis, phthisis bulbi, old interstitial
keratitis, long standing glaucoma and repeated trauma such as multiple
ocular surgeries.
- Systemic conditions that cause increased serum calcium or phosphorus
levels such as multiple myeloma, hyperparathyroidism, sarcoidosis,
metastatic disease and chronic renal failure may all lead to the formation
of band keratopathy.
- Association with chronic exposure to chemical irritants such as
prolonged use of pilocarpine that contain mercurial preservatives
or intraocular substances, including silicone oil for retinal detachment
repair are also noted.
- Management:
- Treatment is indicated for loss of visual acuity, intolerable
eye irritation or cosmesis.
- Repeated application of calcium binding agent EDTA (ethylenediaminetetraacetic
acid) and scraping of the corneal surface after removing the epithelium
is usually effective to treat relatively mild cases.
- Excimer laser phototherapeutic keratectomy has been effectively
performed to treat more extensive cases.
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