title: Corneal ciprofloxacin precipitation during bacterial keratitis.
abstract: OBJECTIVE
  To examine how age affects the risk of developing a white corneal precipitate during ciprofloxacin therapy for bacterial keratitis and to explore the effect of a white precipitate on rates of clinical improvement and cure.
  
  
  METHODS
  Prospective, multicenter, observational cohort study.
  
  
  METHODS
  Occurrence of a white precipitate of the corneal surface was recorded among 624 patients with presumed bacterial keratitis who were treated with topical ciprofloxacin 0.3% solution or ointment. Relative risks of corneal precipitation were estimated from logistic regression for age categories and other clinical characteristics. The time-dependent effects of precipitate on rates of infection resolution and corneal reepithelialization were estimated by proportional hazards regression.
  
  
  RESULTS
  Ninety-five (15.2%) patients developed a white corneal precipitate during ciprofloxacin therapy; 72 (75.8%) began within the first 3 days of treatment. Compared with those younger than 40 years old, patients aged 60 to 69 years had 2.8 (95% confidence limits [CL], 1.9, 3.9) times the risk of ciprofloxacin precipitation; patients 70 years and older had 3.7 (95% CL, 2.6, 5.0) times the risk. Median duration of the visible corneal precipitate was 8.5 days (90% decile, 32 days). Presence of ciprofloxacin precipitation did not significantly affect the time until therapeutic improvement (P =.09) but slowed the time until reepithelialization by 55% (95% CL 32%, 70%).
  
  
  CONCLUSIONS
  Older patients treated with topical ciprofloxacin for bacterial keratitis have a higher risk of corneal deposition. A white precipitate apparently does not interfere with antibacterial therapeutic response but may delay epithelial healing of ulcerative keratitis.
authors.affiliation: Department of Ophthalmology, Baylor College of Medicine, Houston, Texas 77030, USA. kirkw@bcm.tmc.edu
authors.forename: Kirk R
authors.initials: KR
authors.lastname: Wilhelmus
authors.forename: Robert L
authors.initials: RL
authors.lastname: Abshire
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000890:Anti-Infective Agents / Q000009:adverse effects* / Q000627:therapeutic use; D011232:Chemical Precipitation; D002648:Child; D002939:Ciprofloxacin / Q000009:adverse effects* / Q000627:therapeutic use; D003315:Cornea / Q000187:drug effects* / Q000503:physiopathology; D003316:Corneal Diseases / Q000139:chemically induced* / Q000503:physiopathology; D003460:Crystallization; D015818:Eye Infections, Bacterial / Q000188:drug therapy* / Q000382:microbiology / Q000503:physiopathology; D005260:Female; D006801:Humans; D007634:Keratitis / Q000188:drug therapy* / Q000382:microbiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors
chemical_list: D000890:Anti-Infective Agents; D002939:Ciprofloxacin