Does in vitro susceptibility predict clinical outcome in bacterial keratitis?
OBJECTIVE
To determine whether clinical outcomes in bacterial keratitis are associated with antibiotic susceptibility.


METHODS
Retrospective, ancillary study using data and samples from a completed randomized clinical trial.


METHODS
Forty-two patients were enrolled with culture-confirmed bacterial keratitis at Aravind Eye Hospital in South India. All patients received topical moxifloxacin and were randomized to receive either topical prednisolone phosphate or placebo. Outcomes included time to epithelialization, best spectacle-corrected visual acuity (BSCVA), and infiltrate/scar size at three months. Bacterial isolates were cultured, and minimum inhibitory concentration (MIC) to moxifloxacin was measured using Etests. Multiple linear regression was used to assess the effect of MIC on outcome, adjusting for enrollment characteristics.


RESULTS
MIC was associated with three-month infiltrate/scar size: each two-fold increase in MIC was associated with a 0.33-mm average diameter increase in scar size (P=.01). MIC was not associated with three-month BSCVA (P=.71) or time to epithelialization (P=.35).


CONCLUSIONS
MIC was associated with infiltrate/scar size in bacterial keratitis. An ongoing larger, multicenter trial should provide further information on whether this association is maintained across subgroups of organisms.
Chen
Aiyin
A
F.I. Proctor Foundation, Department of Ophthalmology, University of California, San Francisco, San Francisco, California 94143, USA.
Prajna
Lalitha
L
Srinivasan
Muthiah
M
Mahalakshmi
Rajendran
R
Whitcher
John P
JP
McLeod
Stephen
S
Lietman
Thomas M
TM
Acharya
Nisha R
NR
D000890:Anti-Infective Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001372:Aza Compounds / Q000494:pharmacology* / Q000627:therapeutic use; D001419:Bacteria / Q000187:drug effects*; D003320:Corneal Ulcer / Q000175:diagnosis / Q000188:drug therapy / Q000382:microbiology*; D004198:Disease Susceptibility; D015818:Eye Infections, Bacterial / Q000175:diagnosis / Q000188:drug therapy / Q000382:microbiology*; D024841:Fluoroquinolones; D006801:Humans; D008826:Microbial Sensitivity Tests; D000077266:Moxifloxacin; D010865:Pilot Projects; D011239:Prednisolone / Q000627:therapeutic use; D011804:Quinolines / Q000494:pharmacology* / Q000627:therapeutic use; D016032:Randomized Controlled Trials as Topic; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity
D000890:Anti-Infective Agents; D001372:Aza Compounds; D024841:Fluoroquinolones; D011804:Quinolines; D011239:Prednisolone; D000077266:Moxifloxacin