title: Screening for previous refractive surgery in eye bank corneas by using optical coherence tomography.
abstract: OBJECTIVE
  To use optical coherence tomography (OCT) to detect previous refractive surgery in donor corneas.
  
  
  METHODS
  We constructed a tabletop OCT scanner operating at 1310-nm wavelength. Donor corneas at the Cleveland Eye Bank were scanned while sealed within the sterile container immersed in Optisol GS. OCT scanning was performed with 7.6-mm-long lines (512 axial scans) along 8 meridians. Anterior and posterior corneal surfaces were automatically mapped using image processing software that we developed. Curvature was computed from the best parabolic fit in the central 5-mm diameter. Layered analysis of the stromal reflectivity was also performed. Twenty-nine corneas from 19 donors were examined. Five had a history of laser in situ keratomileusis (LASIK).
  
  
  RESULTS
  The flap interfaces could not be visualized on slit-lamp or OCT images but were confirmed by histology. The death-to-scan time was 22.1 +/- 11.4 (SD) hours for normal corneas and 100.6 +/- 57.5 hours for LASIK corneas. The anterior surface power was 67.5 +/- 2.5 D in control corneas and 64.5 +/- 2.4 D in LASIK corneas (P = 0.023). There was no significance between the 2 groups in terms of posterior curvature and thickness parameters. The anterior/posterior reflectivity ratio in the central 4-mm diameter was significantly lower in post-LASIK corneas than in control (P < 0.05).
  
  
  CONCLUSIONS
  OCT provides thickness, topography, and reflectivity maps of donor corneas without taking them out of preservation medium and container. The anterior curvature and the anterior/posterior stromal reflectivity ratio may be useful for detecting previous LASIK.
authors.affiliation: Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.
authors.forename: Roger C
authors.initials: RC
authors.lastname: Lin
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Maolong
authors.initials: M
authors.lastname: Tang
authors.forename: Marcy
authors.initials: M
authors.lastname: McLain
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Rollins
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Izatt
authors.forename: David
authors.initials: D
authors.lastname: Huang
mesh_terms: D000368:Aged; D003315:Cornea / Q000473:pathology* / Q000601:surgery; D016039:Corneal Transplantation; D003941:Diagnostic Techniques, Ophthalmological; D005125:Eye Banks; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D008297:Male; D054140:Refractive Surgical Procedures; D013524:Surgical Flaps / Q000473:pathology; D014019:Tissue Donors; D020858:Tissue and Organ Harvesting; D041623:Tomography, Optical Coherence / Q000379:methods*; D014945:Wound Healing