- 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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