Telangiectasia and optic atrophy in cone-rod degenerations
J. R. Heckenlively, D. A. Martin and T. O. Rosales
The diagnosis of cone-rod dysfunction is made with the electroretinogram
(ERG). Characteristically, the photopic ERG is worse than the scotopic ERG,
and both are abnormal. Of a larger group of patients with retinal
dystrophy, 20 cases of cone-rod dysfunction were identified. All patients
had progressive disease, and all three main modes of inheritance were
represented. There was remarkable similarity of findings among all
patients, including temporal disc atrophy, telangiectasia of disc vessels,
and little to no pigmentary retinal changes. Patients were not night-blind
unless advanced disease was present. These patients suggest that neither
telangiectasia nor temporal optic atrophy is pathognomonic for Leber's
optic neuropathy nor dominant optic atrophy, respectively. Using a
combination of electrophysiologic testing, fundus changes and modes of
inheritance may prove helpful in better classifying the different types of
retinal dystrophies, including retinitis pigmentosa.
