Post-LASIK Infectious Crystalline Keratopathy Caused by Alternaria.

Infectious keratitis is a known complication of laser in situ keratomileusis (LASIK) surgery. Alvarenga et al have reported 3 cases of post-LASIK infectious keratitis resembling infectious crystalline keratopathy (ICK), caused by nontuberculous mycobacteria. We herein report a fourth case of ICK after LASIK, which was caused by Alternaria species.

DISCUSSION

ICK is an uncommon corneal infection. It is usually caused by gram-positive bacteria and fungi and has been reported after corneal transplantation, topical anesthetic abuse, persistent epithelial defect, chronic herpetic keratitis, corneal scar, ocular cicatricial pemphigoid, and LASIK.

The various causative organisms, which have been isolated from cases of ICK, include Streptococus species, Staphylococcus species, Peptostreptococcus, Pseudomonas aeruginosa, Candida tropicalis, Candida albicans, and nontuberculous Mycobacterium. Only one previous case of ICK caused by Alternaria species has been reported after penetrating keratoplasty. To the best of our knowledge, no case of ICK has been reported because of this organism after LASIK surgery. In general, the occurrence of fungal keratitis after LASIK surgery is uncommon.

Alvarenga et al described 3 cases of post-LASIK infectious keratitis that presented as infectious crystalline keratopathy caused by Mycobacterium chelonae, a nontuberculous Mycobacterium. In these cases, fortified topical antibiotics, flap amputation, or keratoplasty was required to control the infection.

The increasing use of broad-spectrum topical antibiotics may provide a noncompetitive environment for Alternaria species to grow and cause opportunistic infection, because these organisms are generally present in external ocular flora. Furthermore, the prolonged use of topical corticosteroids, as was present in our case, may enhance the growth of fungi by suppressing the host immune response.

We recommend early institution of the fortified topical antibiotics along with excision of LASIK flap for control of interface infection. In cases of infectious keratitis after LASIK, where smear and cultures are negative, based on the clinical impression, an early institution of antifungal therapy may be a therapeutic option, especially in nonresponsive cases where antibiotics and corticosteroids have been used for prolonged periods of time. It is possible that an earlier intervention with appropriate antifungal medications such as 5% natamycin may have helped in controlling the infection in our case, thus obviating the need for an emergent penetrating keratoplasty.

Conclusions:

Alternaria species fungus may cause ICK after LASIK.