title: Sterile keratitis after combined riboflavin-UVA corneal collagen cross-linking for keratoconus.
abstract: OBJECTIVE
  To investigate patient risk factors and to look for potential causes of sterile infiltrates following an unexpected cluster of sterile keratitis after a routine collagen cross-linking (CXL) list.
  
  
  METHODS
  The records of all 148 cases of CXL were reviewed retrospectively. The equipment and solutions used and our clinic's standard operating procedure for CXL were reviewed. An in-vitro experiment to explore the variation in ultraviolet A (UVA) irradiance from fluctuations in the working distance of the UVA lamp was conducted.
  
  
  RESULTS
  The four patients who developed sterile infiltrates had steeper maximum corneal curvatures (68.0±7.3 D) and thinner pachymetry (389.9±49.0 μm) than the 144 who did not (57.0±8.2 D, P=0.05; 454.6±45.4 μm, P=0.08). A corneal curvature of >60 Dand a pachymetry of <425 μm were significant risk factors. All four affected cases obtained a complete resolution with topical antibiotics and steroids. The unaided VA and the maximum K improved from their pre-operative levels in three out of four patients. A 2-mm reduction in distance of the VEGA C.B.M. X-Linker from a treated surface increased irradiance to 3.5-3.7 mW/cm(2), which is above the threshold for endothelial toxicity.
  
  
  CONCLUSIONS
  Patients with thinner and steeper corneas are at an increased risk of developing sterile keratitis. The visual outcomes despite this complication are good.
authors.affiliation: The Corneoplastic Unit, Queen Victoria Hospital, West Sussex, UK.
authors.forename: F C
authors.initials: FC
authors.lastname: Lam
authors.forename: P
authors.initials: P
authors.lastname: Georgoudis
authors.affiliation: The Corneoplastic Unit, Queen Victoria Hospital, West Sussex, UK.
authors.forename: P
authors.initials: P
authors.lastname: Geourgoudis
authors.affiliation: The Corneoplastic Unit, Queen Victoria Hospital, West Sussex, UK.
authors.forename: M A
authors.initials: MA
authors.lastname: Nanavaty
authors.affiliation: The Corneoplastic Unit, Queen Victoria Hospital, West Sussex, UK.
authors.forename: S
authors.initials: S
authors.lastname: Khan
authors.affiliation: The Corneoplastic Unit, Queen Victoria Hospital, West Sussex, UK.
authors.forename: D
authors.initials: D
authors.lastname: Lake
mesh_terms: D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D003094:Collagen / Q000378:metabolism*; D063171:Corneal Pachymetry; D003319:Corneal Stroma / Q000378:metabolism; D003432:Cross-Linking Reagents; D005260:Female; D005938:Glucocorticoids / Q000627:therapeutic use; D006801:Humans; D007634:Keratitis / Q000188:drug therapy / Q000209:etiology*; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism; D008297:Male; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011183:Postoperative Complications; D012189:Retrospective Studies; D012256:Riboflavin / Q000627:therapeutic use*; D012307:Risk Factors; D014466:Ultraviolet Rays; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D003432:Cross-Linking Reagents; D005938:Glucocorticoids; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin
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