Review of epidemiological features, microbiological diagnosis and treatment outcome of microbial keratitis: experience of over a decade.
OBJECTIVE
To review the epidemiological characteristics, microbiological profile, and treatment outcome of patients with suspected microbial keratitis.


METHODS
Retrospective analysis of a non-comparative series from the database was done. All the patients presenting with corneal stromal infiltrate underwent standard microbiologic evaluation of their corneal scrapings, and smear and culture-guided antimicrobial therapy.


RESULTS
Out of 5897 suspected cases of microbial keratitis 3563 (60.4%) were culture-proven (bacterial--1849, 51.9%; fungal--1360, 38.2%; Acanthamoeba--86, 2.4%; mixed--268, 7.5%). Patients with agriculture-based activities were at 1.33 times (CI 1.16-1.51) greater risk of developing microbial keratitis and patients with ocular trauma were 5.33 times (CI 6.41-6.44) more likely to develop microbial keratitis. Potassium hydroxide with calcofluor white was most sensitive for detecting fungi (90.6%) and Acanthamoeba (84.0%) in corneal scrapings, however, Gram stain had a low sensitivity of 56.6% in detection of bacteria. Majority of the bacterial infections were caused by Staphylococcus epidermidis (42.3%) and Fusarium species (36.6%) was the leading cause of fungal infections. A significantly larger number of patients (691/1360, 50.8%) with fungal keratitis required surgical intervention compared to bacterial (799/1849, 43.2%) and Acanthamoeba (15/86, 17.4%) keratitis. Corneal healed scar was achieved in 75.5%, 64.8%, and 90.0% of patients with bacterial, fungal, and Acanthamoeba keratitis respectively.


CONCLUSIONS
While diagnostic and treatment modalities are well in place the final outcome is suboptimal in fungal keratitis. With more effective treatment available for bacterial and Acanthamoeba keratitis, the treatment of fungal keratitis is truly a challenge.
Gopinathan
Usha
U
Jhaveri Microbiology Centre, Prof. Brien Holden Eye Research Centre, Hyderabad Eye Research Foundation, L.V. Prasad Eye Institute, Prasad Marg, Banjara Hills, Hyderabad, India.
Sharma
Savitri
S
Garg
Prashant
P
Rao
Gullapalli N
GN
D000048:Acanthamoeba; D000328:Adult; D000562:Amebiasis / Q000175:diagnosis* / Q000188:drug therapy; D000563:Amebicides / Q000627:therapeutic use; D000890:Anti-Infective Agents / Q000627:therapeutic use; D001424:Bacterial Infections / Q000175:diagnosis* / Q000628:therapy; D005260:Female; D006801:Humans; D015994:Incidence; D007194:India / Q000453:epidemiology; D007634:Keratitis / Q000453:epidemiology* / Q000382:microbiology* / Q000469:parasitology / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009181:Mycoses / Q000175:diagnosis* / Q000628:therapy; D013508:Ophthalmologic Surgical Procedures; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
D000563:Amebicides; D000890:Anti-Infective Agents