Infectious keratitis: correlation between corneal and contact lens cultures.
OBJECTIVE
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%).


CONCLUSIONS
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.
Martins
Elisabeth Nogueira
EN
Department of Ophthalmology, Paulista School of Medicine, Federal University of São Paulo, Brazil.
Farah
Michel Eid
ME
Alvarenga
Lênio Souza
LS
Yu
Maria Cecília Zorat
MC
Höflin-Lima
Ana Luisa
AL
D000818:Animals; D001419:Bacteria / Q000302:isolation & purification; D003262:Contact Lenses, Extended-Wear / Q000382:microbiology*; D003263:Contact Lenses, Hydrophilic / Q000382:microbiology; D003315:Cornea / Q000382:microbiology*; D056890:Eukaryota / Q000302:isolation & purification; D015817:Eye Infections / Q000175:diagnosis / Q000382:microbiology*; D005658:Fungi / Q000302:isolation & purification; D006801:Humans; D007634:Keratitis / Q000175:diagnosis / Q000382:microbiology*; D012189:Retrospective Studies