title: Optical analysis of presbyLASIK treatment by a light propagation algorithm.
abstract: OBJECTIVE
  To evaluate the changes in the optical quality of corneas of hyperopic patients operated using central multifocal presbyLASIK treatment through the study of light patterns around the retinal plane.
  
  
  METHODS
  This study included eight hyperopic eyes that underwent central presbyLASIK surgery with Presby-one software using an H. Eye Tech Technovision excimer laser platform. Mean patient age was 57 years. Mean preoperative spherical equivalent refraction was 1.28 +/- 0.87 diopters (D). Mean distance decimal visual acuity with correction was 1.02 +/- 0.13 and without correction was 0.37 +/- 0.15. The optical quality was characterized by the Strehl ratio, the spot size on the retina, and objective decimal visual acuity calculated based on measured corneal topography using Fresnel propagation algorithm based on a realistic eye model.
  
  
  RESULTS
  The postoperative spherical equivalent refraction was -0.55 +/- 0.48 D. The distance decimal visual acuity with correction was 0.94 and without correction was 0.70. The pseudoaccommodation range was 1.60 +/- 0.40 D. A good Pearson correlation coefficient was obtained (r2 = 0.86) for the linear fit between the real and calculated decimal visual acuity for the eight eyes. The Strehl ratio value on the retinal plane increased after the surgery by a mean factor of 4.7.
  
  
  CONCLUSIONS
  With a complete characterization of the eye and a complete propagation algorithm (that takes into account all refractive surfaces in the eye at the same time), it is possible to evaluate the optical quality in eyes of patients who have undergone central presbyLASlK treatment.
authors.affiliation: Research and Investigation Department, Instituto Oftalmológico Alicante, Vissum Corporation, Avda Denia s/n Edificio Vissum, 03016 Alicante, Spain. rdioa@vissum.com
authors.forename: Dolores
authors.initials: D
authors.lastname: Ortiz
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Alió
authors.forename: Carlos
authors.initials: C
authors.lastname: Illueca
authors.forename: David
authors.initials: D
authors.lastname: Mas
authors.forename: Esperanza
authors.initials: E
authors.lastname: Sala
authors.forename: Jorge
authors.initials: J
authors.lastname: Pérez
authors.forename: J
authors.initials: J
authors.lastname: Espinosa
mesh_terms: D000368:Aged; D000465:Algorithms; D003315:Cornea / Q000473:pathology*; D019781:Corneal Topography; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D008875:Middle Aged; D011305:Presbyopia / Q000473:pathology / Q000601:surgery*; D012029:Refraction, Ocular; D016896:Treatment Outcome; D014792:Visual Acuity