title: Overnight orthokeratology-associated microbial keratitis.
abstract: OBJECTIVE
  This study was designed to report the clinical aspects, microbiologic findings, and treatment outcomes of overnight orthokeratology-associated microbial keratitis.
  
  
  METHODS
  Medical records of patients with overnight orthokeratology-associated microbial keratitis at National Taiwan University Hospital from August 2000 to October 2001were reviewed. The clinical and microbiologic characteristics and treatment outcomes were investigated.
  
  
  RESULTS
  Nine patients (in total 10 eyes) from aged 8 to 17 (mean, 12.3 +/- 2.9) years were included in this study. Eight patients had a unilateral infection and one had a bilateral infection. The initial best corrected visual acuities ranged from hand motion to 20/20. The lesions were located at the central cornea in nine eyes (90%). Smears and cultures from corneal scrapings were obtained from all patients. Four eyes were culture-positive, which included nonfermentative Gram-negative bacillus, Pseudomonas aeruginosa and Acanthamoeba. Positive smears from another two eyes revealed Gram-negative bacilli and double-walled cyst. All patients were cured using antimicrobial medications with complete re-epithelization and disappearance of corneal infiltrates. Four eyes had a final best corrected visual acuity of 20/30 or worse after a mean follow-up of 9.4 months, including one eye that had visual acuity of hand motion only. Complications included corneal opacity in all eyes, glaucoma in one eye, and cataract in one eye.
  
  
  CONCLUSIONS
  Overnight orthokeratology is an important risk factor of microbial keratitis, especially in school children. Acanthamoeba and Gram-negative bacilli, especially Pseudomonas aeruginosa, are the most common pathogens in our series. The risk of microbial keratitis after overnight orthokeratology should not be overlooked.
authors.affiliation: Department of Ophthalmology, National Taiwan University Hospital, National Taiwan University, Taipei, Taiwan.
authors.forename: Chia-Hui
authors.initials: CH
authors.lastname: Tseng
authors.forename: Chien-Fan
authors.initials: CF
authors.lastname: Fong
authors.forename: Wei-Li
authors.initials: WL
authors.lastname: Chen
authors.forename: Yu-Chih
authors.initials: YC
authors.lastname: Hou
authors.forename: I-Jong
authors.initials: IJ
authors.lastname: Wang
authors.forename: Fung-Rong
authors.initials: FR
authors.lastname: Hu
mesh_terms: D000048:Acanthamoeba / Q000302:isolation & purification; D015823:Acanthamoeba Keratitis / Q000188:drug therapy / Q000469:parasitology*; D000293:Adolescent; D000818:Animals; D000890:Anti-Infective Agents / Q000627:therapeutic use; D000981:Antiprotozoal Agents / Q000627:therapeutic use; D001251:Astigmatism / Q000628:therapy; D002648:Child; D003261:Contact Lenses / Q000009:adverse effects*; D003315:Cornea / Q000382:microbiology / Q000469:parasitology; D003320:Corneal Ulcer / Q000188:drug therapy / Q000382:microbiology*; D004359:Drug Therapy, Combination; D015818:Eye Infections, Bacterial / Q000188:drug therapy / Q000209:etiology*; D005260:Female; D006090:Gram-Negative Bacteria / Q000302:isolation & purification; D006801:Humans; D008297:Male; D009216:Myopia / Q000628:therapy; D012307:Risk Factors; D016896:Treatment Outcome; D014792:Visual Acuity
chemical_list: D000890:Anti-Infective Agents; D000981:Antiprotozoal Agents