title: Contact lens-assisted collagen cross-linking (CACXL): A new technique for cross-linking thin corneas.
abstract: OBJECTIVE
  To report a novel method of contact lens-assisted corneal cross-linking (CACXL) in eyes with thin corneas.
  
  
  METHODS
  Patients diagnosed as having progressive keratectasia with a minimum corneal thickness less than 400 and greater than 350 μm after epithelial abrasion were included. After epithelial abrasion, the iso-osmolar riboflavin 0.1% in dextran was applied every 3 minutes for 30 minutes. An ultraviolet barrier-free soft contact lens (0.09-mm thickness, 14-mm diameter) soaked in iso-osmolar riboflavin 0.1% for 30 minutes was placed on the cornea. Once the minimum corneal thickness value was confirmed to be greater than 400 μm, the ultraviolet-A irradiance was started along with instillation of iso-osmolar riboflavin 0.1% in the pre-corneal and pre-contact lens region. Intraoperative minimum corneal thickness changes were recorded with ultrasound pachymetry and optical coherence tomography. Postoperative visual acuity, corneal topography (Orbscan; Bausch & Lomb, Rochester, NY), endothelial cell loss (EM-3000; Tomey, Nagoya, Japan), and stromal demarcation line (Visante; Carl Zeiss Meditec, Jena, Germany) were measured.
  
  
  RESULTS
  Fourteen eyes underwent the procedure. Mean preoperative minimum corneal thickness after epithelial abrasion was 377.2 ± 14.5 μm (range: 350 to 398 μm). There was a significant difference in minimum functional corneal thickness (Friedman test, P = .000) intraoperatively, before epithelial abrasion, after epithelial abrasion, and with contact lens and riboflavin film. Mean minimum functional corneal thickness after the contact lens was 485.1 ± 15.8 μm (range: 458 to 511 μm). Mean absolute increase in the minimum corneal thickness along with the contact lens and pre-corneal riboflavin film was 107.9 ± 9.4 μm (range: 90 to 124 μm). Mean depth of stromal demarcation line was 252.9 ± 40.8 μm (range: 208 to 360 μm). There was no significant endothelial loss (P = .063) and the corneal topography was stable at the last follow-up (P = .505).
  
  
  CONCLUSIONS
  CACXL technique was effective and safe in performing cross-linking in corneas less than 400 μm after epithelial abrasion and appeared effective based on stromal demarcation line depth.
authors: Soosan
authors: S
authors: Jacob
authors: Dhivya Ashok
authors: DA
authors: Kumar
authors: Amar
authors: A
authors: Agarwal
authors: Sushanth
authors: S
authors: Basu
authors: Pratheek
authors: P
authors: Sinha
authors: Ashvin
authors: A
authors: Agarwal
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003094:Collagen / Q000378:metabolism; D003263:Contact Lenses, Hydrophilic; D003315:Cornea / Q000187:drug effects / Q000473:pathology*; D063171:Corneal Pachymetry; D003319:Corneal Stroma / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000008:administration & dosage*; D004108:Dilatation, Pathologic / Q000188:drug therapy / Q000378:metabolism; D016503:Drug Delivery Systems; D005260:Female; D006801:Humans; D007640:Keratoconus / Q000188:drug therapy* / Q000378:metabolism; D008297:Male; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage; D010865:Pilot Projects; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D012256:Riboflavin / Q000008:administration & dosage; D041623:Tomography, Optical Coherence; D016896:Treatment Outcome; D014466:Ultraviolet Rays; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult
chemical_list: D003432:Cross-Linking Reagents; D017319:Photosensitizing Agents; D003094:Collagen; D012256:Riboflavin