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

To analyze risk factors and prognosis factors of severe bacterial keratitis.

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).

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).

Bacterial keratitis is a sight-threatening infection. Gram-positive keratitis is more frequent, except for contact lens wearers, and is also more severe.