KERATOCONUS AND CORNEAL FAMILIAL TOPOGRAP HIC ABNORMALITIES

Purpose: Computer-assisted corneal topography, allows the detection of early abnormalities, including abortive or subclinical forms of kerat oconus. So, it is possible to identify affected individuals with varia bles degrees, in family members of patients with keratoconus, to draw pedigrees, and to specify the mode of inheritance. Methods: Computer-a ssisted digital videophotokeratoscope was used to map the corneas of 1 06 family members of 30 patients with keratoconus. Results: Abnormalit ies observed included the inferior cornea markedly steeper than the su perior cornea (I-S - 0.86 +/- 0.44 D) and a marked difference between the central corneal powers of the two eyes (Delta PC = 0.72 +/- 0.22 D ). However, there no statistical difference with normal individual dua ls for central corneal power. Conclusion: Pedigree analysis in these f amilies suggests, in 50% of them, an autosomal dominant mode of inheri tance. However, it is impossible to conclude for the other families, b ecause of an insufficient number of cases.