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.