title: Size of the Lesions of Superficial Punctate Keratitis in Dry Eye Syndrome Observed With a Slit Lamp.
abstract: OBJECTIVE
  To evaluate the size distribution of epithelial lesions of superficial punctate keratitis (SPK) in dry eye after staining of the ocular surface by sodium fluorescein.
  
  
  METHODS
  Fluorescein was instilled in 10 patients with dry eye graded using the Oxford Scheme. Pictures were taken using a standard Topcon slit lamp with cobalt blue light, without barrier filter. Two magnifications (×10 and ×16) were used and calibrated using a certified standard reference grating, allowing the diameter of the observed objects to be determined with ImageJ software. The most visible and isolated SPK lesions (green dots) were selected. The size of 254 SPK lesions was measured by tracing the irradiance profile and manually measuring the full width at half maximum.
  
  
  RESULTS
  For all patients, with the 2 magnifications combined, the median diameter was 20.9 μm (15.2-26.6 μm, 10-90 percentile). There was a significant difference between the size of SPK lesions measured with ×10 and ×16 magnifications, respectively, 24.3 μm (18.2-29.8) versus 19.0 μm (15.2-26.6) (P < 0.001).
  
  
  CONCLUSIONS
  Lesions seem to be smaller than normal superficial epithelial cells (which are approximately 25 × 50 μm) and might correspond to the staining of dying shrunken cells, according to recent investigations. These new quantitative data will help in developing automated recognition algorithms to obtain reliable objective classification of corneal staining.
authors.affiliation: *Corneal Graft Biology, Engineering and Imaging Laboratory, EA2521, Federative Institute of Research in Sciences and Health Engineering, Faculty of Medicine, Jean Monnet University, Saint-Etienne, France; †Hubert Curien Laboratory (UMR 5516 CNRS), Jean Monnet University, Saint-Etienne, France; ‡Ophthalmology Department, University Hospital, Saint-Etienne, France; and §Institut Universitaire de France, Paris, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Courrier
authors.forename: Thierry
authors.initials: T
authors.lastname: Lépine
authors.forename: Guillaume
authors.initials: G
authors.lastname: Hor
authors.forename: Corinne
authors.initials: C
authors.lastname: Fournier
authors.forename: Zhiguo
authors.initials: Z
authors.lastname: He
authors.forename: Mehdi
authors.initials: M
authors.lastname: Chikh
authors.forename: Caroline
authors.initials: C
authors.lastname: Urrea
authors.forename: Fahran-Falgi
authors.initials: FF
authors.lastname: Al Anazi
authors.forename: Gilles
authors.initials: G
authors.lastname: Thuret
authors.forename: Philippe
authors.initials: P
authors.lastname: Gain
mesh_terms: D015352:Dry Eye Syndromes / Q000175:diagnosis*; D019573:Epithelium, Corneal / Q000473:pathology*; D019793:Fluorescein / Q000008:administration & dosage; D005456:Fluorescent Dyes / Q000008:administration & dosage; D006801:Humans; D007634:Keratitis / Q000175:diagnosis*; D066167:Slit Lamp; D013194:Staining and Labeling / Q000379:methods
chemical_list: D005456:Fluorescent Dyes; D019793:Fluorescein