AIM: To identify the
risk factors for, and to report the
microbiological findings and clinical outcomes of, severe
microbial keratitis (MK). METHODS: This was a retrospective study of all cases of presumed MK admitted to a tertiary referral center over a 2-year period (September 2001 to August 2003). Data recorded included demographic data, details relating to possible
risk factors, results of
microbiological studies, clinical findings at presentation, and clinical and
visual outcomes. RESULTS: Ninety patients were admitted with a diagnosis of presumed MK during the study period. The
mean age of patients was 45 +/- 32 years, and the male to female ratio was 47:43 (52.2%:47.7%). Predisposing
risk factors for MK included
contact lens wear (37; 41.1%),
anterior segment disease (19; 21.1%), ocular trauma (13; 14.4%), systemic disease (5; 5.6%), and previous ocular
surgery (1; 1.1%). Cultured organisms included
gram-negative bacteria (17; 51.5%),
gram-positive bacteria (11, 33.3%),
acanthamoeba (2; 6.1%), and
fungi (1; 3%).
Visual acuity improved significantly after treatment [
mean best-corrected
visual acuity (+/-
standard deviation) at presentation: 0.76 (+/-0.11);
mean best-corrected
visual acuity at last follow-up: 0.24 (+/-0.07); P < 0.001]. Secondary
surgical procedures were required in 18 (20%) cases, and these included punctal cautery (1; 1.1%), tissue
glue repair of
corneal perforation (2; 2.2%),
tarsorrhaphy (9; 9.9%),
Botulinum toxin-induced ptosis (1; 1.1%),
penetrating keratoplasty (3; 3.3%), and evisceration (2; 2.2%). CONCLUSIONS:
Contact lens wear remains a significant
risk factor for severe MK. MK remains a threat to vision and to the
eye, but the majority of cases respond to prompt and appropriate
antimicrobial therapy.
