Topographical analysis of the effects of corneal relaxing incisions on high postkeratoplasty astigmatism.
We used simple visual inspection of keratoscope mires to determine proper placement of corneal relaxing incisions in 4 patients with high postkeratoplasty astigmatism. Retrospectively, the LSU topography analysis system was used to evaluate the pattern of power distribution seen pre- and postoperatively in this group. Analysis of preoperative photographs showed that none of the patients had a classic spherocylindrical pattern of corneal power distribution. Areas of maximum steepening of corneal slope were often present in the peripheral portions of the graft away from the steep hemimeridians suggested by visual inspection of the keratoscope photographs. Since these areas were not recognized preoperatively, steepening remained in the areas postoperatively. These results suggest that preoperative computer analysis of keratoscope photographs may be superior to visual inspection of the photographs in determining proper placement of relaxing incisions.
Maguire
L J
LJ
Department of Ophthalmology, Mayo Clinic, Rochester, Minn.
Bourne
W M
WM
D001251:Astigmatism / Q000209:etiology / Q000601:surgery*; D003196:Computer Graphics; D003315:Cornea / Q000601:surgery*; D016039:Corneal Transplantation; D006801:Humans; D007091:Image Processing, Computer-Assisted; D011183:Postoperative Complications / Q000209:etiology / Q000601:surgery*