Keratolysis, or sterile melting of the cornea, may occur following cataract extraction. It is most frequently associated with preexisting tear-film abnormalities resulting from keratoconjunctivitis sicca, Sjögren syndrome, or collagen vascular diseases such as rheumatoid arthritis. Preoperative recognition of these predisposing factors is valuable because the frequent perioperative use of topical lubricants can lessen morbidity. Punctum plug placement or lateral tarsorrhaphy may also be performed at the time of surgery.
Severe stromal melting with the postoperative use of topical nonsteroidal anti-inflammatory drugs has also been reported. The melting is due in part to the epithelial toxicity and hypoesthesia induced by these drugs. A generic form of diclofenac was most frequently implicated, presumably because of matrix metalloproteinase expression induced by a solubilizer in the topical formulation.
Persistent epithelial defects accompanied by stromal dissolution require intensive treatment with nonpreserved topical lubricants. Use of topical medications, particularly preserved medications, should be minimized so that epithelial toxicity is reduced. Additional treatment modalities to encourage epithelialization and arrest stromal melting include punctal occlusion, bandage contact lenses, tarsorrhaphy, serum eyedrops (containing epithelial growth factor), and systemic tetracyclines. The prophylactic use of topical antibiotics must be monitored closely. After a week’s application, many topical antibiotics begin to cause secondary toxic effects that may inhibit epithelial healing. For the treatment of any underlying collagen vascular disease, systemic immunosuppressive therapy such as methotrexate, cyclophosphamide, cyclosporine, or anti-TNF agents may be needed.
If the disease continues to progress in spite of medical therapy, the surgeon may undertake placement of amniotic membrane or lamellar or penetrating keratoplasty. Because corneal melting may recur even with grafted tissue, the physician must maintain intensive lubrication and consider management of any underlying systemic diseases in these cases.