title: Comparison of Results of Accelerated Corneal Cross-Linking With Hypo-Osmolar Riboflavin Solution Performed on Corneas Thicker and Thinner Than 400 μm.
abstract: OBJECTIVE
  To evaluate the effect of accelerated corneal cross-linking (CXL) according to corneal thickness in keratoconus.
  
  
  METHODS
  Patients undergoing corneal CXL (9 mW/cm(2)) with hypo-osmolar riboflavin solution were included in this study. The patients were divided into 2 groups. Group 1 included patients with corneal thickness below 400 μm (50 eyes from 45 patients), and group 2 included patients with corneal thickness above 400 μm (50 eyes from 47 patients). Visual acuity (VA), refraction, topographic values, and higher-order aberrations were evaluated in the preoperative term and postoperatively at months 1, 3, and 6.
  
  
  RESULTS
  The improvements in VA were significant and similar in both groups [0.25/0.19 logMAR, P = 0.130]. In group 1, the rate of decrease in spherical refraction [0.85/0.27 diopters (D), P = 0.012] and maximum keratometry (Kmax, 2.49/0.68 D, P < 0.001) was significantly higher than that in group 2. The cylindrical change was similar (0.43/0.29 D P = 0.173). Corneal thinning was higher in group 2 (25/40.4 μm P < 0.001). Anterior elevation values decreased at higher rates in group 1 (3.73/0.24 μm P < 0.001); neither group showed a significant difference in posterior elevation (-0.14/-0.4 μm P > 0.05). In group 1, all aberration values except trefoil significantly decreased, whereas in group 2 none of the aberrations decreased except the total root mean square. All higher-order aberration values decreased at significantly higher rates in group 1 (P < 0.05).
  
  
  CONCLUSIONS
  In thin corneas, accelerated corneal CXL provides better anatomical changes; however, the improvement in VA is similar to that in thick corneas.
authors.affiliation: *Department of Ophthalmology, Ulucanlar Eye Training and Research Hospital, Ankara, Turkey; †Department of Ophthalmology, Kafkas University, Kars, Turkey; and ‡Department of Ophthalmology, Kayserigöz Hospital, Kayseri, Turkey.
authors.forename: Mustafa
authors.initials: M
authors.lastname: Koç
authors.forename: Mehmet Murat
authors.initials: MM
authors.lastname: Uzel
authors.forename: Yaran
authors.initials: Y
authors.lastname: Koban
authors.forename: Irfan
authors.initials: I
authors.lastname: Durukan
authors.forename: Kemal
authors.initials: K
authors.lastname: Tekin
authors.forename: Pelin
authors.initials: P
authors.lastname: Ylmazbaş
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; D057108:Corneal Wavefront Aberration / Q000503:physiopathology; D003432:Cross-Linking Reagents; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology; D008297:Male; D009994:Osmolar Concentration; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000737:chemistry / Q000627:therapeutic use*; D012029:Refraction, Ocular / Q000502:physiology; D012189:Retrospective Studies; D012256:Riboflavin / Q000737:chemistry / Q000627:therapeutic use*; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin