Infectious keratitis is a rare but potentially devastating complication of LASIK with an incidence of 0.02% for  unilateral disease, less for bilateral disease. Causal organisms include

• Staphylococcus aureus
• Nocardia asteroides
• Staphylococcus pneumoniae
• Mycobacterium chelonae
• Mycobacterium fortuitum and
• Staphylococcus viridans.

 ONSET DELAYED INFECTIOUS KERATITIS

 When the etiology of onset delayed infectious keratitis is unclear, a mycobacterial infection should be suspected.

• Infection usually manifests from 2 to 8 weeks after ocular surgery or trauma.
• Delayed diagnosis and protracted course even with intensive antibiotic therapy.
• Topical amikacin is the drug of choice to treat nontuberculous mycobacterium keratitis. Clarithromycin 1% to 4% is also effective. It penetrates intact epithelium more efficiently; however, some organisms remain resistant to the drug.
• Mycobacteria are best cultured on Lowenstein-Jensen agar.
• Corticosteroids should be used with caution when mycobacteria are suspected in the etiology of keratitis.

 OTHER POSSIBLE CAUSES OF INFECTIOUS KERATITIS

• Microscopic breach in epithelium
• Problems with healing of corneal wounds
  – Delayed wound healing
  – Epithelial inclusion cysts
  – Irregular stromal and epithelial architecture of the cornea
• Bandage contact lenses increase risk of infection.
• Exposure to mycobacterium species during LASIK surgery

 TREATMENT GUIDELINES FOR INFECTIOUS KERATITIS (1)

• Use 2 fortified topical antibiotics; alternate every one-half hour for 48 hours.
• If the condition improves, taper the frequency of administration of both antibiotics to q 2 h after 48 hours.
• After 72 hours, discontinue one of the fortified antibiotics and change to a nonfortified topical antibiotic; taper the frequency of administration of the second fortified antibiotic to q 3 h.
  – If the epithelial layer has healed and the antibiotic regimen matches the culture and sensitivity profiles, consider using a topical steroid.
• After 5 days, change to regular-strength antibiotic and taper the medication if clinically indicated.

 HIGHLIGHTS OF THIS CASE

• The patient had onset delayed bilateral keratitis following LASIK.
• The patient’s condition showed minimal or delayed response to medical treatment with antibiotics.
• Surgical management: A flap rescue procedure was performed with a tissue adhesive.
• Additional surgical management: A lamellar keratoplasty was necessary to treat the corneal perforation. However, the corneal glue was applied in the first procedure to further sterilize the cornea and allow the descemetocele to heal.
• This case raises the question of the safety of bilateral simultaneous LASIK.