Abstract
PURPOSE: To generate a normative donor topographic database from rasterstereography images of whole globes acquired in an eye-bank setting with minimal manipulation or handling
SETTING: Eye-bank laboratory
METHODS: In a retrospective study, rasterstereography topographic images that had been prospectively collected in duplicate of donor eyes received by the Central Ohio Lions Eye Bank between 1997 and 1999 were analyzed Best-fit sphere (BFS) and simulated keratometry (K) values were extracted. These values were recalculated after application of custom software to correct any tilt of the mapped surfaces relative to the image plane The mean value variances between right eyes and left eyes, between consecutive scans, and after untilting were analyzed by repeated-measures analysis of variance and t tests (P <= 05)
RESULTS: A keratographic database of 556 pair-matched right and left eyes was generated. Normal distributions were observed in frequency histograms of each value (P> 05, Kolmogorov-Smirnov) There was no difference between right and left eyes or consecutive scans (P> 05) The mean values changed when the images were tilt-corrected (P<.05) The right eye BFS, Kflat, and Ksteep values of 42.03 diopters (D) +/- 1.88 (SD), 42 21 +/- 210 D, and 43.82 +/- 200 D, respectively, increased to 42.52 +/- 1 73 D. 43.05 +/- 1 99 D. and 44.57 +/- 2 02 D, respectively, after tilt correction.
CONCLUSIONS: Keratometric parameter frequency distributions from the donor database of tilt-corrected data were normal in distribution and comparable to parameters reported for normal eyes in a living population. These findings show the feasibility and reliability of routine donor-eye topography by rasterstereography