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, a nd -13.0+/-3.2 D for convex applanation surfaces with a vertex of +100 mu m, +125 mu m, and +150 mu m in the microkeratome and +1.5+/-2.0 an d +2.5+/-2.6D for concave applanation surfaces with a vertex of -100 p m and -125 mu m. The pachymetric corneal changes were +43+/-24 mu m, 39+/-32 mu m, and +71+/-24 mu m for the convex applanation surfaces an d -21+/-40 mu m and -17+/-24 mu m for the concave. Wound healing was u ncomplicated. The scar at the interface was 0-5 mu m wide. The mean ce ntral density of nerve endings was 1,255+/-532/mm(2). The endothelial cell size was 25.1% (p < 0.01) greater as measured by specular microsc opy than by vital preparation technique; this difference was greater w ith higher (33.4%) than with lower (18.02%) corneal refraction (p = 0. 02). In addition, there was a method-independent correlation (correlat ion coefficient, -0.63) between endothelial cell count and corneal thi ckness. This may indicate an increased demand on corneal endothelium i n thickened corneas.