Keratokyphosis in rabbits: a functional and morphologic study.

Keratokyphosis, a "nonfreeze keratomileusis" procedure, was applied in rabbits. The refractive changes were -6.5 +/- 0.7 (SD), -9.5 +/- 2.6, and -13.0 +/- 3.2 D for convex applanation surfaces with a vertex of +100 microns, +125 microns, and +150 microns in the microkeratome and +1.5 +/- 2.0 and +2.5 +/- 2.6 D for concave applanation surfaces with a vertex of -100 microns and -125 microns. The pachymetric corneal changes were +43 +/- 24 microns, +39 +/- 32 microns, and +71 +/- 24 microns for the convex applanation surfaces and -21 +/- 40 microns and -17 +/- 24 microns for the concave. Wound healing was uncomplicated. The scar at the interface was 0-5 microns wide. The mean central density of nerve endings was 1,255 +/- 532/mm2. The endothelial cell size was 25.1% (p < 0.01) greater as measured by specular microscopy than by vital preparation technique; this difference was greater with higher (33.4%) than with lower (18.02%) corneal refraction (p = 0.02). In addition, there was a method-independent correlation (correlation coefficient, -0.63) between endothelial cell count and corneal thickness. This may indicate an increased demand on corneal endothelium in thickened corneas.

Duke Scholars

Author W. Robert Lee Radiation Oncology