Band Keratopathy

Band keratopathy is a calcific degeneration with deposition of calcium salts (hydroxyapatite) in the Bowman layer, epithelial basement membrane and anterior stroma, in the interpalpebral zone.

• Ocular causes: chronic anterior uveitis (especially juvenile idiopathic arthritis associated), chronic glaucoma, phthisis bulbi, long standing corneal oedema, silicone oil in the anterior chamber, interstitial keratitis, and chronic corneal inflammation.
• Systemic causes of hypercalcaemia or hyperphosphataemia: hyperparathyroidism, vitamin D excess, sarcoidosis, milk alkali syndrome, renal failure, multiple myeloma, metastatic bone disease, and gout.
• Toxic: mercury vapour, preservatives (phenylmercuric nitrate) in topical drugs.
• Genetic: familial and idiopathic forms.

• Greyish white band across the interpalpebral cornea, starting at the limbus nasal and temporal sides (3 and 9 o'clock) with a clear zone between the opacity and limbus, with small holes (Swiss cheese pattern).
• Progression centrally causing reduced vision, glare, foreign body sensation, epithelial breakdown and erosions.
• Rough surface and calcium flakes in advanced cases.

• Slit lamp examination (direct, retroillumination); anterior segment OCT to measure depth.
• Systemic workup: serum calcium (corrected), phosphate, parathyroid hormone, 25-hydroxyvitamin D, urea and creatinine, serum ACE and chest imaging if sarcoid, and urinalysis; look for causes of uveitis (juvenile idiopathic arthritis, HLA-B27).
• Review intraocular pressure and anterior segment disease.

• Treat the underlying cause (uveitis control, hypercalcaemia, glaucoma, silicone oil removal).
• Lubricants for mild asymptomatic disease.
• Chelation with disodium edetate (EDTA) 0.37 to 1.85 percent: remove the epithelium over the opacity, apply a sponge or reservoir soaked in EDTA for 5 to 15 minutes (repeat until clear), then irrigate with balanced salt solution and polish with a blade or burr. Place a bandage contact lens with antibiotic cover (moxifloxacin 0.5 percent four times daily) until re-epithelialised (3 to 5 days).
• Phototherapeutic keratectomy (excimer laser) for deeper and denser deposits, with hyperopic shift risk.
• Superficial keratectomy, amniotic membrane graft for large defects.
• Recurrence is frequent, particularly if the underlying cause persists; repeat as needed.
• Lamellar keratoplasty for deep scarring.