[Clinical, microbiological and therapeutic features of severe bacterial keratitis].

PURPOSE: To analyze risk factors and prognosis factors of severe bacterial keratitis.
METHODS: Retrospective study of 111 eyes from 105 patients hospitalized from 2005 to 2006 for bacterial keratitis proven by microbiological assessment or suspected (favorable outcome after antibiotic treatment).
RESULTS: The main risk factors were contact lens wear (39.6%), ocular surface diseases (36.9%), a history of ocular surgery (27.9%), and ocular trauma (11.7%). Gram-positive cocci were found in 46.8% of cases, Gram-negative bacilli in 19.8%, Gram-positive bacilli in 7.2%, Gram-negative cocci in 2.7%, and Gram-negative coccobacilli in 0.9%. No infectious agents were found in 22.5% of the cases. Two or more bacteria were found in 25.6%. The mean follow-up time was 6.5 months. Resolution of infection was obtained in 77.5% with only medical treatment and in 99.1% with further surgical treatment. Amniotic membrane transplantation was performed in 16.2% and emergency keratoplasty in 8.1%. The mean LogMAR visual acuity was 1.43 initially and 0.84 at the last examination. The final visual acuity was 1.03 for Gram-positive and 0.35 for Gram-negative organisms (p=0.03).
CONCLUSION: Bacterial keratitis is a sight-threatening infection. Gram-positive keratitis is more frequent, except for contact lens wearers, and is also more severe.