title: INTACS inserts using the femtosecond laser compared to the mechanical spreader in the treatment of keratoconus.
abstract: OBJECTIVE
  To determine the efficacy of INTACS insertion using a femtosecond laser in the treatment of keratoconus and to compare it to the technique using a mechanical spreader.
  
  
  METHODS
  INTACS were inserted in 10 eyes using the mechanical spreader to create the channels and subsequently on another 20 eyes using the femtosecond laser. Uncorrected (UCVA) and best spectacle-corrected visual acuity (BSCVA), manifest refraction, and corneal topography were measured prior to surgery, at 6 months (femtosecond group), and 1 year (mechanical group). Pre- and postoperative data were analyzed to determine changes in the above parameters.
  
  
  RESULTS
  Both groups showed significant reduction in average keratometry (K), spherical equivalent refraction, BSCVA, UCVA, surface regularity index (SRI), and surface asymmetry index (SAI). The laser group performed better in all parameters except change in SRI. Results of the laser versus the mechanical spreader were as follows: reduction in spherical equivalent refraction (3.98 vs 2.96), change in average K (2.91 vs 2.52), improvement in UCVA (4.13 vs 3.63), improvement in BSCVA (3.92 vs 1.63), change in SRI (0.37 vs 0.64), and change in SAI (1.00 vs 0.70). Statistical analysis, however, did not reveal any statistically significant differences between the two groups for any single parameter studied. The biggest improvement in the laser group versus the mechanical group was BSCVA (P=.09). Overall success, defined as contact lens or spectacles tolerance, was 85% in the laser group and 70% in the mechanical group.
  
  
  CONCLUSIONS
  Inserting INTACS using the femtosecond laser to create the channels is as effective as using the mechanical spreader.
authors.affiliation: Cornea Genetic Eye Institute, Cedars-Sinai Medical Center, 444 S San Vicente Blvd, #1102, Los Angeles, CA 90048, USA. rabinowitzy@cshs.org
authors.forename: Yaron S
authors.initials: YS
authors.lastname: Rabinowitz
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Li
authors.forename: Teresa S
authors.initials: TS
authors.lastname: Ignacio
authors.forename: Ezra
authors.initials: E
authors.lastname: Maguen
mesh_terms: D000328:Adult; D003319:Corneal Stroma / Q000473:pathology / Q000601:surgery*; D019781:Corneal Topography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007640:Keratoconus / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D053685:Laser Therapy / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D019736:Prostheses and Implants; D011474:Prosthesis Design; D019919:Prosthesis Implantation / Q000379:methods*; D014792:Visual Acuity