title: Clinical characterization of corneal ectasia after myopic laser in situ keratomileusis based on anterior corneal aberrations and internal astigmatism.
abstract: OBJECTIVE
  To evaluate and characterize the clinical features of corneal ectasia after myopic laser in situ keratomileusis (LASIK) considering internal astigmatism and corneal aberrations and their correlation with other clinical data.
  
  
  METHODS
  Vissum-Instituto de Oftalmológico de Alicante, Alicante, Spain.
  
  
  METHODS
  Retrospective comparative case series.
  
  
  METHODS
  In this multicenter study, eyes were divided into 2 groups. The study group comprised eyes that had corneal ectasia after myopic LASIK. The control group comprised eyes that had successful LASIK to correct high myopia. The clinical outcomes were analyzed and compared. Internal astigmatism was calculated using vectorial analysis.
  
  
  RESULTS
  The study enrolled 91 eyes (48 study group; 40 control group) of 81 patients (age 18 to 67 years). Uncorrected and corrected (CDVA) distance visual acuities and the refractive status were significantly worse in the study group (P ≤ .01). Corneas in the study group had a significantly higher steepest keratometry (K) reading and a more negative central asphericity (P < .01). Internal astigmatism and corneal aberrations were also significantly higher in the study group (P < .01). The CDVA was significantly correlated with primary spherical aberration (r = -0.561, P =.01) and primary coma root mean square (r = 0.451, P =.04). Age was significantly correlated with mean K (r = -0.44, P =.01) and internal astigmatism (r = -0.34, P =.04).
  
  
  CONCLUSIONS
  Larger levels of internal astigmatism and anterior corneal aberrations leading to a visual deterioration were present in eyes with corneal ectasia after myopic LASIK.
  
  
  BACKGROUND
  No author has a financial or proprietary interest in any material or method mentioned.
authors.affiliation: Keratoconus Unit , Vissum-Instituto Oftalmológico de Alicante, the Division of Ophthalmology, Universidad Miguel Hernández, Universidad de Alicante, Alicante, Spain.
authors.forename: David P
authors.initials: DP
authors.lastname: Piñero
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Alió
authors.forename: Rafael I
authors.initials: RI
authors.lastname: Barraquer
authors.forename: Antonio
authors.initials: A
authors.lastname: Uceda-Montanes
authors.forename: Joaquim
authors.initials: J
authors.lastname: Murta
mesh_terms: D057128:Aberrometry; D000293:Adolescent; D000328:Adult; D000368:Aged; D001251:Astigmatism / Q000175:diagnosis*; D003315:Cornea / Q000473:pathology*; D019781:Corneal Topography; D057108:Corneal Wavefront Aberration / Q000175:diagnosis*; D004108:Dilatation, Pathologic / Q000175:diagnosis; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D011183:Postoperative Complications; D012189:Retrospective Studies; D014792:Visual Acuity; D055815:Young Adult