title: A combined incision technique of radial keratotomy. A comparison to centripetal and centrifugal incision techniques in human donor eyes.
abstract: OBJECTIVE
  To evaluate and compare the extent of corneal flattening and the anatomy of the incision grooves produced by centrifugal, centripetal, and combined incisions in a human donor eye model.
  
  
  METHODS
  Twenty-seven eyes, divided into three groups of nine, received eight-incision radial keratotomy using the centrifugal, centripetal, or combined incision technique. Corneal curvature was evaluated using a topography system, and the anatomy of the incision was assessed by light microscopy and scanning electron microscopy.
  
  
  RESULTS
  The average central corneal flattening at the 3-mm clear zone was 4.16 +/- 1.47 diopters (D) for centrifugal incisions; 7.71 +/- 2.77 D for centripetal incisions; and 9.26 +/- 1.75 D for combined incisions. The difference in corneal flattening between eyes that received centrifugal versus either centripetal or combined incisions was significant (P < 0.01), whereas the difference between combined and centripetal incisions was not significant (P = 0.174). Anatomic differences were observed within the incision grooves produced by the three techniques.
  
  
  CONCLUSIONS
  The authors describe a novel combined incision technique of radial keratotomy that provides the potential safety of a centrifugal incision with the effect of a centripetal incision.
authors.affiliation: Anheuser-Busch Eye Institute, St. Louis University School of Medicine, Department of Ophthalmology, MO 63104.
authors.forename: K K
authors.initials: KK
authors.lastname: Assil
authors.forename: J
authors.initials: J
authors.lastname: Kassoff
authors.forename: D J
authors.initials: DJ
authors.lastname: Schanzlin
authors.forename: A J
authors.initials: AJ
authors.lastname: Quantock
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003315:Cornea / Q000502:physiology / Q000601:surgery* / Q000648:ultrastructure; D005069:Evaluation Studies as Topic; D006801:Humans; D007646:Keratotomy, Radial / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D014019:Tissue Donors