title: [Clinical results of transepithelial corneal collagen cross-linking in the treatment of keratoconus].
abstract: OBJECTIVE
  To evaluate the effect of transepithelial corneal collagen cross-linking (CXL) in the treatment of keratoconus.
  
  
  METHODS
  Prospective study. Sixteen eyes of 16 patients with keratoconus underwent transepithelial CXL, and the fellow eyes were considered as the controls. The mean age was (22.4±6.5) years old. In the CXL group, topical anesthesia (0.1% tetracaine) was given for 15 minutes, and 0.5% riboflavin was applied until saturated in the anterior chamber. Then an ultraviolet A irradiance of 3 mW/cm(2) on the cornea was performed for 30 minutes. Postoperative corneal reepithelization time was recorded. Preoperative and postoperative examinations included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), refractive error, topography, corneal biomechanical parameters, thinnest corneal thickness, and endothelial cell density.
  
  
  RESULTS
  The mean corneal reepithelization time was 1.0(1.0 to 2.0) days. In the transepithelial CXL group, at the end of the 12-month follow-up, CDVA and refractive outcomes were significantly improved (P<0.05). Maximum K-value, anterior and posterior elevations were significantly decreased by (-2.23 ± 2.82)D (t=-3.153, P=0.007), (-4.69 ± 4.99) μm (t=-3.758, P=0.002), and (-13.94 ± 25.81) μm (t=-2.160, P=0.047), respectively. Corneal hysteresis, corneal resistance factor, thinnest corneal thickness, and endothelial cell density showed no significant difference (P>0.05). The differences in the changes of UDVA, CDVA, spherical equivalent refraction, and maximum K-value between the CXL and control groups were significant at 12 months (P<0.05).
  
  
  CONCLUSIONS
  Transepithelial CXL is effective in optimizing the irregular corneal surface of keratoconus, and might halt its progression. (Chin J Ophthalmol, 2016, 52: 525-530).
authors.affiliation: The Affiliated Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China.
authors.forename: S H
authors.initials: SH
authors.lastname: Chen
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.forename: Y N
authors.initials: YN
authors.lastname: Li
authors.forename: P
authors.initials: P
authors.lastname: Ding
authors.forename: Q M
authors.initials: QM
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000867:Anterior Chamber; D016022:Case-Control Studies; D003094:Collagen / Q000378:metabolism*; D003315:Cornea; D003319:Corneal Stroma / Q000378:metabolism*; D019781:Corneal Topography; D003432:Cross-Linking Reagents / Q000627:therapeutic use*; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000627:therapeutic use*; D011184:Postoperative Period; D011446:Prospective Studies; D012256:Riboflavin / Q000627:therapeutic use; D014466:Ultraviolet Rays; D014787:Vision Tests; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin