Computer-assisted corneal topography in family members of patients with keratoconus
Y. S. Rabinowitz, J. Garbus and P. J. McDonnell
Doheny Eye Institute, University of Southern California School of Medicine, Los Angeles 90033.
In about 6% of patients with keratoconus, there is a history of familial
disease. High keratometric astigmatism and mildly irregular mires observed
by placidois disc have been suggested to represent variable forms of
expression of a gene in family members of patients with keratoconus. We
used a computer-assisted digital videophotokeratoscope to map the corneas
of 28 family members of 5 patients with keratoconus. Abnormalities observed
in family members included central steepening, greater steepening of the
cornea inferior to the apex, and substantial asymmetry in the central
dioptric power between the two eyes of the same individual. These findings
were similar to, but less severe than, those found in patients with
keratoconus and may represent the variable expression of a gene
contributing to the development of keratoconus. Pedigree analysis in these
families suggests an autosomal dominant mode of inheritance.
