Treatment of fungal keratitis by penetrating keratoplasty

Aim—To study the use of penetrating keratoplasty (PKP) for the treatment of severe fungal keratitis that could not be cured by antifungal medication. Methods—A retrospective analysis of 108 cases of severe fungal keratitis in which PKP was performed served as the basis for this study. Fungal keratitis was diagnosed by KOH staining of corneal scrapings or by confocal microscopic imaging of the cornea. All patients received a combination of topical and oral antifungal medicines without steroids as the first course of therapy. Patients whose corneal infection was not cured or in whom the infection progressed during antifungal treatment were given a PKP. After surgery, the patients continued to receive antifungal therapy with gradual tapering of the dose over a 1–2 month period. Cyclosporine was used to prevent graft rejection beginning 2 weeks after PKP. Topical steroid only was administered to the patient whose donor graft was over 8.5 mm and with a heavy iris inflammation 2 weeks after PKP. The surgical specimens were used for microbiological evaluation and examined histopathologically. The patients were followed for 6–24 months after PKP. Graft rejection, clarity of the graft, visual acuity, and surgical complications were recorded. Results—Corneal grafts in 86 eyes (79.6%) remained clear during follow up. There was no recurrence of fungal infection and the visual acuity ranged from 40/200 to 20/20. Complications in some patients included recurrent fungal infection in eight eyes (7.4%), corneal graft rejection in 32 eyes (29.6%), secondary glaucoma in two eyes (1.9%), and five eyes (4.6%) developed cataracts. 98 of 108 of the recipient corneas had PAS positive fungal hyphae in tissue sections; 97 of 108 were culture positive for various fungi, including Fusarium (63), Aspergillus (14), Candida (9), Penicillium (4), and seven cases in which septate hyphae were seen but identification of the organism was not conclusive. Conclusions—PKP is an eVective treatment for fungal keratitis that does not respond to antifungal medication. Early surgical intervention before the disease becomes advanced is recommended. It is critical that the surgical procedure remove the infected tissue in its entirety in order to eVect a cure. (Br J Ophthalmol 2001;85:1070–1074) Fungal keratitis is a major blinding eye disease in China. Within the past decade there has been an increase in the frequency of microbial keratitis caused by fungi. A contributing factor for the development of fungal infection is ocular trauma and contamination of corneal lesions by soil and plant material. Another factor which may contribute to the increased incidence of fungal keratitis is the widespread use of broad spectrum antibiotics and steroids. It is also apparent that improved diagnostic methods and instruments have facilitated the process of identifying corneal fungal infections. 3 Not surprisingly, the majority of cases occur in farmers; the incidence of corneal fungal infection is especially high in rural areas where the climate is warm and humid. Epidemiological studies suggest that many of the patients who develop fungal keratitis live a considerable distance from an ophthalmological clinic. Furthermore, because of the diYculty of accurately diagnosing fungal keratitis, many patients from rural areas had a long duration of disease and severe corneal infection including corneal perforation by the time that they were referred to our hospital. Very little information has been published regarding the treatment of advanced fungal infection of the cornea in such patients and some ophthalmologists only perform penetrating keratoplasty (PKP) as a last resort. 5 In an eVort to prevent loss of vision in severe cases of corneal infection which did not respond to fungal chemotherapy we performed 108 corneal transplants between January 1996 and December 1999. The outcome of these cases is presented with an average follow up of 18.3 months. Patients and methods Between January 1996 and December 1999, 358 patients with a preliminary diagnosis of fungal keratitis were referred to our hospital. One hundred and eight of these patients (30.2%) required a corneal transplant to save their eyes and cure the disease. Shandong Eye Institute and Hospital is a referral centre for a large rural area and population. All 358 patients were subjected to diagnostic testing including potassium hydroxide (KOH) analysis and culture for fungi. We relied more heavily on the results of the microscopic analysis of KOH treated scrapings because we obtained significantly fewer positive results from the culture. Confocal microscopy was used to support the KOH results. Initial treatment involved antifungal chemotherapy as detailed below. When this treatment failed the patients were recommended for PKP. Br J Ophthalmol 2001;85:1070–1074 1070 Shandong Eye Institute and Hospital, Qingdao 266071, PR China