Clinical and microbiological profile of Bacillus keratitis

Purpose. To examine the clinical and microbiological profile of Bacillus ke ratitis. Methods. A retrospective review was done of all medical and labora tory records of patients with infectious keratitis in an urban tertiary lev el eye-care center in South India between January 1991 and June 1997. Resul ts. Nineteen eyes of 17 patients having microbiologically proven Bacillus k eratitis were reviewed. The mean age of the patients was 32.64 years (range , 3-70). The duration of symptoms ranged from 1 day to 3 months, with 11 ey es seen within a week of onset of symptoms. Trauma (five eyes), lagophthalm os (two eyes), topical corticosteroid therapy (one eye), bullous keratopath y (two eyes), previous corneal scars (two eyes), and diabetes (one eye) wer e identified as predisposing factors. Severe corneal features, disproportio nate to the duration of symptoms, were present in most of the eves. Gram st ain of corneal scrapings showed variably stained bacilli in eight (42.1%) c ases. Polymicrobial infection was present in six eyes (two fungal, four bac terial). Of the 16 isolates tested for in vitro antibiotic susceptibility, 100% were sensitive to gentamicin, 15 (93.75%) were sensitive to ciprofloxa cin and norfloxacin, 14 (87.5%) were sensitive to chloramphenicol, and 10 ( 62.5%) were sensitive to cefazolin. Whereas 12 (63.1%) eyes required only m edical therapy, adjunctive procedures were required in seven (36.8%) eyes. The ulcers healed (mean time to healing, 37.3 +/- 28.6 days) in 16 eyes (lo st to follow-up, three). Visual acuity had improved after treatment in 10 ( 71.4%) of 14 eyes in whom vision could be recorded. Conclusion. Bacillus is an unusual pathogen in thr clinical setting of infectious keratitis. The i nfection is mostly amenable to treatment with commonly used antibiotics, an d the final outcome is often satisfactory.