title: Objective optical quality analysis using double-pass technique in pterygium surgery.
abstract: OBJECTIVE
  To analyze objective optical quality changes after pterygium surgical excision using the Optical Quality Analysis System.
  
  
  METHODS
  Forty eyes with primary pterygium suitable for surgical treatment were included. Uncorrected distance visual acuity, corrected distance visual acuity (CDVA), objective scattering index (OSI), and cutoff frequency of the modulation transfer function (MTFcutoff) were recorded preoperatively and at 1 and 6 months postoperatively. Slit-lamp measurement of pterygium size was performed to classify them: small in group 1 and medium size/large in group 2. A paired comparative study of all data that included preoperative with 1-month results (comparison A), preoperative with 6-month results (comparison B), and 1 month with sixth-month results (comparison C) was performed.
  
  
  RESULTS
  In global analysis, uncorrected distance visual acuity and OSI showed significant changes in comparison A, all parameters in comparison B, and CDVA, OSI, and MTFcutoff in comparison C. When subdividing into groups, in group 1, there was significant improvement between preoperative uncorrected distance visual acuity value and those at 1 and 6 months. Significant improvement in CDVA, OSI, and MTFcutoff values were observed in comparisons B and C. In group 2, MTFcutoff values significantly improved in comparisons B and C. The comparison of mean values between each group at each evaluation showed a lower value for MTFcutoff at 1 month after surgery. A comparative analysis of the evolution between both groups based on pterygium size did not reveal significant differences.
  
  
  CONCLUSIONS
  Pterygium can undermine visual quality, and its excision provides significant improvement even at 6 months after surgery. Optical Quality Analysis System proved useful for postoperative outcomes.
authors.affiliation: Department of Ophthalmology, Donostia University Hospital, San Sebastian, Spain.
authors.forename: Nahia
authors.initials: N
authors.lastname: Goñi
authors.forename: Aritz
authors.initials: A
authors.lastname: Bidaguren
authors.forename: Beatriz
authors.initials: B
authors.lastname: Macías-Murelaga
authors.forename: Txomin
authors.initials: T
authors.lastname: Alberdi
authors.forename: Itziar
authors.initials: I
authors.lastname: Martinez-Soroa
authors.forename: Javier
authors.initials: J
authors.lastname: Mendicute
mesh_terms: D005260:Female; D006801:Humans; D008027:Light; D008297:Male; D008875:Middle Aged; D013508:Ophthalmologic Surgical Procedures; D011446:Prospective Studies; D011625:Pterygium / Q000503:physiopathology* / Q000601:surgery*; D012542:Scattering, Radiation; D014787:Vision Tests / Q000295:instrumentation*; D014792:Visual Acuity / Q000502:physiology*