Infectious keratitis: correlation between corneal and contact lens cultures.

PURPOSE: This article reports a study of the effectiveness of performing contact lens cultures to identify causative organisms of infectious keratitis in patients using extended-wear soft contact lenses (cosmetic or therapeutic). METHODS: Patients' records from the Ocular Microbiology Laboratory of the Department of Ophthalmology, Paulista School of Medicine, from 1976 to 2000, and data of patients with contact lens-related keratitis in which the contact lens had been cultured were collected and reviewed. RESULTS: One hundred thirteen patients were included. Only soft contact lenses had been cultured and 29.2% of them were therapeutic contact lenses. An overall concordance of 84.0% was found between cultures obtained from corneal scrapings and contact lenses, with a higher rate in fungal keratitis (100%) compared to amebic (80.0%) and bacterial (74.5%) keratitis. In cases of concomitant bacterial growth in cultures of scrapings and contact lenses, the same organism was detected in 97.04%. Most cases of bacterial infection were caused by Pseudomonas spp. Among the discordant cases (16%), a microorganism was more likely to be isolated by contact lens culture (94.4%). CONCLUSION: Contact lens cultures may identify the causative organisms in most cases of contact lens-related keratitis. The clinical relevance of positive contact lens cultures in keratitis with negative corneal cultures needs further investigation.

Therapeutic contact lens-related bilateral fungal keratitis.

PURPOSE: To describe a rare case of bilateral Candida keratitis after contact lens use following bilateral penetrating keratoplasty (PK). METHODS: A 40-year-old female with a clinical diagnosis of Sjögren's syndrome was being followed for corneal thinning in both eyes. She suffered a spontaneous bilateral perforation and underwent penetrating keratoplasty. Therapeutic contact lenses were prescribed for both eyes owing to persistent epithelial defects. Two months later, a biomicroscopic examination revealed corneal infiltrates. RESULTS: A corneal tissue sample, saline, and contact lens cultures were all positive for Candida albicans. Topical and systemic antifungal therapy successfully cleared the infection in the right eye; however, the left eye underwent another corneal graft surgery. CONCLUSIONS: Infectious fungal keratitis may be a complication of wearing therapeutic contact lenses after PK, in a patient with Sjögren's syndrome. The pre-existing eye disease is an important associated factor in cases of yeast infection; therefore, adequate care of these patients and careful follow-up after PK are indicated as measures to prevent early infections.