The shape factor in radial keratotomy.
The corneal contour as defined by the shape factor was found by photokeratoscopy both before and after radial keratotomy to reduce myopia. In 51 eyes with mean pre-operative myopia of -5.67 DS there was a mean reduction of -5.23 DS, and the shape factor became negative in all cases. A relationship was found between the pre-operative myopia and the shape factor, and the size of optical zone to be left untouched when attempting to achieve emmetropia. The importance of taking shape factor into account when forming the surgical plan was made apparent by retrospective study of the surgery performed.
D000328:Adult; D003315:Cornea / Q000473:pathology / Q000601:surgery*; D006801:Humans; D007646:Keratotomy, Radial / Q000379:methods*; D008875:Middle Aged; D009216:Myopia / Q000473:pathology / Q000601:surgery*; D013813:Therapy, Computer-Assisted