title: Straylight and contrast sensitivity after corneal refractive therapy.
abstract: OBJECTIVE
  To compare intraocular straylight and contrast sensitivity determined before corneal refractive therapy and after 15 days and 1 month of treatment.
  
  
  METHODS
  A single-center, prospective, and longitudinal study was performed in 30 subjects undergoing corneal refractive therapy. In each subject, high-contrast visual acuity (HCVA), low-contrast visual acuity (LCVA), straylight, and contrast sensitivity were determined at baseline and after 15 days and 1 month after the treatment. Straylight was measured using the van den Berg straylight meter (third generation). Contrast sensitivity was determined under both photopic and mesopic conditions using the VCTS 6500 instrument (Vision Contrast Test System). EDTRS charts (logMAR units) were used to measure HCVA and LCVA.
  
  
  RESULTS
  Straylight (mean ± standard deviation) significantly fell from baseline (0.94 ± 0.14) to the values recorded at 1 month (0.85 ± 0.11, p = 0.009). Photopic contrast sensitivity remained stable yet mesopic contrast sensitivity measured at high spatial frequencies was significantly reduced. No correlations between intraocular straylight and contrast sensitivity, HCVA, or LCVA were observed 15 days and 1 month after corneal refractive therapy.
  
  
  CONCLUSIONS
  Our findings suggest improved intraocular straylight readings 1 month after starting the treatment, although the changes observed in straylight could not be related to changes in mesopic and photopic contrast sensitivity or HCVA and LCVA. Mesopic contrast sensitivity was more affected by the treatment intervention than photopic contrast sensitivity.
authors.affiliation: Department of Optics II, University School of Optics and Clinicas Novovision, Madrid, Spain. alorente@opt.ucm.es
authors.forename: Amalia
authors.initials: A
authors.lastname: Lorente-Velázquez
authors.forename: Amelia
authors.initials: A
authors.lastname: Nieto-Bona
authors.forename: César Villa
authors.initials: CV
authors.lastname: Collar
authors.forename: Ana González
authors.initials: AG
authors.lastname: Mesa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D015350:Contrast Sensitivity; D003315:Cornea / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D019466:Glare; D006801:Humans; D007223:Infant; D020731:Keratomileusis, Laser In Situ; D008027:Light; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011446:Prospective Studies; D012030:Refractive Errors / Q000503:physiopathology*; D012542:Scattering, Radiation; D055815:Young Adult