title: Technique of area measurement of epithelial defects.
abstract: OBJECTIVE
  To compare two commonly used methods of area measurement of corneal epithelial defects, namely, estimation of the area of an equivalent rectangle and use of image analysis software, the gold standard.
  
  
  METHODS
  Thirty-eight patients with corneal epithelial defects were evaluated. The largest linear dimension of the epithelial defect and its largest possible perpendicular within the confines of the epithelial defect were measured using a slit lamp. The area was then measured using digital photographs and image analysis software. A paired sample t test was used to compare the results.
  
  
  RESULTS
  The two measurements of area correlated well (P = 0.84); their difference was insignificant (P = 0.063) and a linear regression relation between the two could be derived with an r2 value of 0.71, which was significant.
  
  
  CONCLUSIONS
  Accurate slit-lamp measurements with estimation of the area of an equivalent rectangle can safely be used as a measure of the epithelial defect size when sophisticated image analysis software is not available.
authors.affiliation: Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India.
authors.forename: Nitin
authors.initials: N
authors.lastname: Mukerji
authors.forename: Rasik B
authors.initials: RB
authors.lastname: Vajpayee
authors.forename: Namrata
authors.initials: N
authors.lastname: Sharma
mesh_terms: D000328:Adult; D003316:Corneal Diseases / Q000473:pathology*; D003936:Diagnosis, Computer-Assisted; D003941:Diagnostic Techniques, Ophthalmological / Q000592:standards; D019573:Epithelium, Corneal / Q000473:pathology*; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D010781:Photography