Lamellar keratoplasty for the treatment of fungal keratitis

Abstract

Purpose: To determine the therapeutic value of lamellar keratoplasty (LKP) in the treatment of fungal keratitis not curable by antifungal chemotherapy.

Methods: Fifty-five patients, in whom a diagnosis of fungal keratitis was confirmed by microscopic analysis of corneal scrapings or confocal microscopy, and who were not cured by topical and oral antifungal medication, were given LKP. After LKP, topical antifungal treatment was continued for 2 weeks with gradual tapering of the drugs. The excised recipient lamella was used for microbial culture and histopathologic examination.

Results: Therapeutically beneficial results were achieved in 51 cases (92.7%) of the 55 LKPs that were performed. In these 51 cases, there was no recurrence of infection, and the resulting visual acuity ranged from 20/63 to 20/20. Patient follow-up ranged from 6 to 18 months. In four cases (7.3%), there was a recurrence of the fungal infection within 2 weeks of LKP. In these four patients, the infection was cured by performing a penetrating keratoplasty (PKP). Forty-six of the recipient lamellae were culture positive for fungi. Thirty-three of these cultures were identified as Fusarium, six as Aspergillus, three as Candida, one as Penicillium species, and in the other three cases, unidentified septate hyphae were noted. In the four cases of recurrent infection, microbiologic culture revealed three cases with Fusarium species and one case with Aspergillus species. Histopathologic analysis of periodic acid-Schiff (PAS)-stained tissue sections of donor lamellae revealed fungal filaments in all samples. Immune reactions to the lamellar grafts were not observed and the donor lamellae remained clear for the duration of follow-up.

Conclusion: Lamellar keratoplasty can be effective for treating fungal keratitis that is not cured by antifungal therapeutics. In addition, LKP can provide useful vision with few complications. Furthermore, corneal tissue used in LKP may be obtained more easily than healthy tissue used in PKP.