title: The Impact of Topical Corticosteroids Used in Conjunction with Antiamoebic Therapy on the Outcome of Acanthamoeba Keratitis.
abstract: To examine the impact of topical corticosteroid use after the start of antiamoebic therapy (AAT) on the outcomes of Acanthamoeba keratitis (AK) therapy.
  
  
  
  Cohort study.
  
  
  
  A total of 196 patients diagnosed with AK at Moorfields Eye Hospital, London, between January 1991 and April 2012. In 13 patients with bilateral AK, 1 eye was randomly excluded from analysis.
  
  
  
  Patient demographics and clinical examination findings were collected both at the start of AAT and subsequently at the time that topical corticosteroid therapy was initiated. Preliminary a priori investigations were used to identify effect modifiers/confounders and extreme associations requiring consideration in multivariate regression modeling. A multivariable logistic model, optimized for assessment of corticosteroid use after the start of AAT, was used to estimate the odds ratios (ORs) of a suboptimal outcome.
  
  
  
  Suboptimal outcome was defined as final visual acuity ≤20/80, corneal perforation, or the need for keratoplasty.
  
  
  
  In multivariable analysis, restricted to 129 eyes (1 eye per patient) free of scleritis and hypopyon at the start of AAT, topical corticosteroids were not associated with worse outcomes (OR, 1.08; 95% confidence interval [CI], 0.39-3.03), even when corticosteroids had been used before the start of AAT. Risk factors significantly associated with worse outcomes were topical corticosteroid use before the start of AAT (OR, 3.85; 95% CI, 1.35-11.03), a corneal ring infiltrate (together with at least 1 other feature of AK) present at the start of AAT (OR, 5.89; 95% CI, 1.17-29.67), and age ≥33 years at the start of AAT (OR, 4.02; 95% CI, 1.46-11.06).
  
  
  
  Many corneal specialists currently are uncertain about the risk benefit associated with the use of topical corticosteroids for the management of inflammatory complications of AK. The evidence from this study gives clinicians and patients reassurance that the potential benefits of topical corticosteroid therapy, for treating pain and discomfort, are not associated with worse outcomes when initiated after starting modern AAT. Other potential benefits, in terms of resolution of inflammatory complications, will not be demonstrated without a carefully designed randomized clinical trial.
authors.affiliation: Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; Save Sight Institute, University of Sydney, Sydney, Australia.
authors.forename: Nicole
authors.initials: N
authors.lastname: Carnt
authors.affiliation: Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; Save Sight Institute, University of Sydney, Sydney, Australia.
authors.forename: Dana
authors.initials: D
authors.lastname: Robaei
authors.affiliation: Save Sight Institute, University of Sydney, Sydney, Australia.
authors.forename: Stephanie L
authors.initials: SL
authors.lastname: Watson
authors.affiliation: EpiVision Ophthalmic Epidemiology Consultants, Buckinghamshire, UK.
authors.forename: Darwin C
authors.initials: DC
authors.lastname: Minassian
authors.affiliation: National Institute of Health Research Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom. Electronic address: j.dart@ucl.ac.uk.
authors.forename: John K G
authors.initials: JK
authors.lastname: Dart
mesh_terms: D015823:Acanthamoeba Keratitis / Q000188:drug therapy* / Q000503:physiopathology; D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D000368:Aged; D000981:Antiprotozoal Agents / Q000627:therapeutic use*; D001550:Benzamidines / Q000627:therapeutic use; D015331:Cohort Studies; D004359:Drug Therapy, Combination; D015822:Eye Infections, Parasitic / Q000188:drug therapy* / Q000503:physiopathology; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D009883:Ophthalmic Solutions; D012189:Retrospective Studies; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D000981:Antiprotozoal Agents; D001550:Benzamidines; D005938:Glucocorticoids; D009883:Ophthalmic Solutions; C046651:propamidine isethionate