title: Femtosecond laser correction of presbyopia (INTRACOR) in emmetropes using a modified pattern.
abstract: OBJECTIVE
  To evaluate functional results and corneal changes after femtosecond laser correction of presbyopia (INTRACOR, Technolas Perfect Vision GmbH) in emmetropes using a modified treatment pattern over a 12-month period.
  
  
  METHODS
  Twenty eyes from 20 emmetropic patients were treated with a modified intrastromal INTRACOR pattern consisting of 5 central rings and 8 radial cuts in a prospective, nonrandomized, uncontrolled, open, single-center, clinical study. Refraction, visual acuity, endothelial cell density, corneal pachymetry, total corneal power, and stray light were evaluated preoperatively and 1 (except endothelial cell density and stray light), 3, 6, and 12 months postoperatively. Patients filled out a subjective questionnaire at 12 months postoperatively.
  
  
  RESULTS
  Comparison of preoperative versus 12-month postoperative median values revealed a significant improvement in uncorrected near visual acuity (UNVA) from 0.60 (20/80) to 0.10 logMAR (20/25) (P<.0001) and a significant decrease in corrected distance visual acuity (CDVA) from -0.10 (20/16) to 0.00 logMAR (20/20), which equals a median loss of one line (P=.0005). Fifteen percent of patients lost two lines of CDVA in the treated eye. Subjective spherical equivalent refraction remained unchanged at 0.00 diopters (D) (P=.194). After INTRACOR treatment, significant corneal steepening of 1.40 D and midperipheral flattening of 0.50 D occurred (both P<.0001). Corneal pachymetry at the thinnest point and endothelial cell density did not change significantly (P=.829 and P=.058, respectively).
  
  
  CONCLUSIONS
  After 12 months, the modified INTRACOR pattern improved UNVA in emmetropic patients without inducing a myopic shift or significant changes in endothelial cell density or pachymetry.
authors.affiliation: International Vision Corection Research Centre, Department of Ophthalmology, University of Heidelberg, Germany.
authors.forename: Bettina C
authors.initials: BC
authors.lastname: Thomas
authors.forename: Anna
authors.initials: A
authors.lastname: Fitting
authors.forename: Gerd U
authors.initials: GU
authors.lastname: Auffarth
authors.forename: Mike P
authors.initials: MP
authors.lastname: Holzer
mesh_terms: D057128:Aberrometry; D000368:Aged; D002452:Cell Count; D063171:Corneal Pachymetry; D003319:Corneal Stroma / Q000601:surgery*; D057108:Corneal Wavefront Aberration / Q000503:physiopathology*; D058453:Emmetropia / Q000502:physiology*; D004728:Endothelium, Corneal / Q000473:pathology; D005260:Female; D006801:Humans; D053685:Laser Therapy / Q000379:methods*; D008027:Light; D008297:Male; D008875:Middle Aged; D011305:Presbyopia / Q000601:surgery*; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D012542:Scattering, Radiation; D011795:Surveys and Questionnaires; D014792:Visual Acuity / Q000502:physiology