Clinical outcomes and prognostic factors associated with acanthamoeba keratitis.
OBJECTIVE
To describe the clinical characteristics, time of presentation, risk factors, treatment, outcomes, and prognostic factors on a recent series of Acanthamoeba keratitis (AK) treated at our institution.


METHODS
Retrospective case series of 59 patients diagnosed with AK from January 1, 2004 to December 31, 2008. Of these 59 patients, 51 had complete follow-up data and were analyzed using univariate and multivariate logistic regression analyses performed with "failure" defined as requiring a penetrating keratoplasty (PKP) and/or having (1) best-corrected visual acuity (BCVA) < 20/100 or (2) BCVA < 20/25 at the last follow-up. A single multivariate model incorporating age, sex, steroid use before diagnosis, time to diagnosis, initial visual acuity (VA), stromal involvement, and diagnostic method was performed.


RESULTS
Symptom onset was greatest in the summer and lowest in the winter. With failure defined as requiring PKP and/or final BCVA < 20/100, univariate analysis suggests that age > 50 years, female sex, initial VA < 20/50, stromal involvement, and patients with a confirmed tissue diagnosis had a significant risk for failure; however, none of these variables were significant using multivariate analysis. Univariate analysis, with failure defined as requiring PKP and/or final BCVA < 20/25, showed stromal involvement and initial VA < 20/50 were significant for failure-only initial VA < 20/50 was significant using multivariate analysis.


CONCLUSIONS
Symptom onset for AK is greatest in the summer. Patients with confirmed tissue diagnosis and female patients may have a higher risk for failure, but a larger prospective population-based study is required to confirm this. Failure is likely associated with patients who present with stromal involvement and patients presenting with an initial BCVA worse than 20/50.
Cornea Service, Wills Eye Institute, Jefferson Medical College, Thomas Jefferson University, Philadelphia, PA, USA. hall.chew@utoronto.ca
Hall F
HF
Chew
Elvin H
EH
Yildiz
Kristin M
KM
Hammersmith
Ralph C
RC
Eagle
Christopher J
CJ
Rapuano
Peter R
PR
Laibson
Brandon D
BD
Ayres
Ya-Ping
YP
Jin
Elisabeth J
EJ
Cohen
D015823:Acanthamoeba Keratitis / Q000175:diagnosis* / Q000453:epidemiology* / Q000628:therapy; D000293:Adolescent; D000328:Adult; D000368:Aged; D000981:Antiprotozoal Agents / Q000627:therapeutic use; D002648:Child; D003315:Cornea / Q000469:parasitology / Q000473:pathology; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015948:Keratoplasty, Penetrating; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D012621:Seasons; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology
D000981:Antiprotozoal Agents