Band Keratopathy

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.