title: The Effect of Corneal Epithelium on Corneal Curvature in Patients with Keratoconus.
abstract: OBJECTIVE
  To investigate the effects of corneal epithelium on corneal curvature in patients with keratoconus.
  
  
  METHODS
  This is a prospective, nonrandomized study.
  
  
  METHODS
  Fifty-nine eyes of 47 patients diagnosed as keratoconus and for whom corneal collagen crosslinking (CXL) was recruited in this study.
  
  
  METHODS
  This study is a single-center clinical trial. Pregnancy, lactation, connective tissue disease, corneal thickness below 350 μm, severe dry eyes, or scar of corneal surgery were exclusion criteria. Before and during CXL procedure after removing the corneal epithelium, maximum values of corneal apical curvature, simulated keratometry 1 (Sim-K1), simulated keratometry 2 (Sim-K2), temporal and inferior curvature values, all of which are 1.5 mm from the corneal center, were calculated. These values before and after removal of epithelium were compared statistically.
  
  
  RESULTS
  Mean age of patients was 23.30 ± 5.5 (12-38) years. Twenty-eight (59%) were male while 19 (41%) were female. Mean values measured before and after removing the corneal epithelium were: apical curvature; 59.19 ± 7.2 (47.06-82.40) diopter (D) and 61.70 ± 8.8 (49.19-92.66) D (p = 0.001), SimK1; 47.57 ± 4.3 (39.14-64.57) D and 48.23 ± 4.3 (41.89-66.70) D (p = 0.001), SimK2; 52.04 ± 5.3 (43.56-69.34) D and 53.34 ± 5.6 (43.73-70.89) D (p = 0.001), inferior curvature; 53,85 ± 5.2 (43.47-76.56) D and 55.05 ± 5.8 (44.56-81.93) D (p = 0.002), temporal curvature 49.49 ± 5.1 (41.50-71.03) D and 51.53 ± 5.4 (41.58-73.34) D (p = 0.001), respectively.
  
  
  CONCLUSIONS
  In keratoconus patients during CXL treatment, after removing the corneal epithelium, more steepness is detected in the curvature of the steeper area of the cornea. When evaluating patients with keratoconus, the masking effect of corneal epithelium on values of curvature should be taken into consideration.
authors.affiliation: a Yildirim Beyazit University, Ankara Ataturk Training and Research Hospital , Ankara , Turkey.
authors.forename: Emine Kalkan
authors.initials: EK
authors.lastname: Akcay
authors.affiliation: a Yildirim Beyazit University, Ankara Ataturk Training and Research Hospital , Ankara , Turkey.
authors.forename: Betul Seher
authors.initials: BS
authors.lastname: Uysal
authors.affiliation: a Yildirim Beyazit University, Ankara Ataturk Training and Research Hospital , Ankara , Turkey.
authors.forename: Ozge
authors.initials: O
authors.lastname: Sarac
authors.affiliation: a Yildirim Beyazit University, Ankara Ataturk Training and Research Hospital , Ankara , Turkey.
authors.forename: Nagehan
authors.initials: N
authors.lastname: Ugurlu
authors.affiliation: a Yildirim Beyazit University, Ankara Ataturk Training and Research Hospital , Ankara , Turkey.
authors.forename: Fatma
authors.initials: F
authors.lastname: Yulek
authors.affiliation: a Yildirim Beyazit University, Ankara Ataturk Training and Research Hospital , Ankara , Turkey.
authors.forename: Nurullah
authors.initials: N
authors.lastname: Cagil
authors.affiliation: a Yildirim Beyazit University, Ankara Ataturk Training and Research Hospital , Ankara , Turkey.
authors.forename: Nabi
authors.initials: N
authors.lastname: Aslan
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003094:Collagen / Q000378:metabolism; D003315:Cornea / Q000473:pathology*; D063171:Corneal Pachymetry; D003319:Corneal Stroma / Q000378:metabolism; D019781:Corneal Topography; D003432:Cross-Linking Reagents; D003646:Debridement; D019573:Epithelium, Corneal / Q000473:pathology*; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000175:diagnosis* / Q000188:drug therapy / Q000378:metabolism; D008297:Male; D017319:Photosensitizing Agents; D011446:Prospective Studies; D012256:Riboflavin / Q000627:therapeutic use; D014466:Ultraviolet Rays; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin
keywords: Cornea; crosslinking; curvature; epithelium; keratoconus