Fungal keratitis in France

Abstract

Editor, Fungal keratitis is a sight-threatening corneal infection, which is common in tropical regions. Even if its incidence has increased over the last few years, its prevalence remains low in temperate countries (Rondeau et al. 2002). This study was conducted by retrospective analysis of the files of all patients attending to the Centre Hospitalier National d’Ophtalmologie des Quinze-Vingts in Paris, who presented culture-proven fungal keratitis during a 16-year period (from January 1993 through December 2008). The characteristics of the population, clinical findings, etiologic organisms, treatments, predisposing factors and prognosis factors of fungal keratitis were analysed. Considering the response to medical treatment, eyes were divided in two groups: the group of ‘positive response to medical treatment’ (i.e. infection resolution with no surgical procedures) and the group of ‘no response to medical treatment’ (i.e. need for keratoplasty, evisceration or enucleation). During the study, 63 patients (64 eyes) with culture-proven fungal keratitis were followed up. The average age was 50.3 + 17.9 [37 men (59%) and 26 women (41%)]. Population characteristics at baseline are shown in Table 1. Before 2000, topical corticosteroids were the main predisposing factor for keratomycosis, representing 50% (10/20) of cases, whereas from 2001 to 2008 contact lens wear was the most frequent, representing 50% (22/44) of cases (p = 0.002). Concerning contact lens care practice and multipurpose solutions for cleaning, between January 2004 through November 2006, 14 contact lens wearers were diagnosed with Fusarium keratitis. Six patients reported using ReNu with MoistureLoc, and eight patients reported using other brands of contact lens cleaning solution. The risk factors included the continued use of contact lenses after the planned replacement date (35%), the overnight use of daily wear contact lenses (5%) and swimming with contact lenses in swimming pools (24%). Filamentous fungi (69%) were more common than yeast fungi (31%). The predominant fungal species was Fusarium spp (44%). Before 2000, Candida species were the most common fungi, representing 50% (10/20) of cases, whereas from 2001 to 2008 Fusarium species were the most frequent, representing 52% (23/44) of cases (p = 0.04). The patients were treated with topical amphotericin B 0.15% (97%) and/or topical natamycin 5% (25%), topical voriconazole 1% (16%) or topical caspofungin (13%). Systemic antifungal drugs (voriconazole or itraconazole or fluconazole) were administrated in 33 patients (52%). Clinical outcomes are listed in Table 1. A history of eye disease before infection (i.e. ocular surface diseases or keratoplasty) was significantly associated with no response to medical treatment (p = 0.01). Patient age older than 50 years (p = 0.03) was significant risk factor for low final visual acuity. In our study, soft contact lens wear and the use of the alexidine-containing contact lens cleaning solution ReNu with MoistureLoc were associated with Fusarium keratitis, consistent with previous observations (Chang et al. 2006; Gaujoux et al. 2008). Imamura et al. (2008) established an in vitro model of Candida and Fusarium biofilm formation on contact lenses, which reduced susceptibility against contact lens solutions. In France, there has been an increase in fungal keratitis and a change in the causative pathogens and risk factors for keratomycosis. Fusarium species are the most common species of fungi isolated, and contact lens wear is the main risk factor. Similar changes occurred in the Boston area (Jurkunas et al.2009). The results suggest that patients with a history of eye disease (i.e. ocular surface diseases or keratoplasty) and patients older than 50 years are at high risk of severe clinical outcome. Therefore, special care should be offered to these patients by the administration of intense dose of antifungals by topical and general route. This study was supported by the Paris VI University (Université Pierre et Marie Curie), Paris, France.