Electrophysiology findings in a large family with central areolar choroidal dystrophy

Purpose: To perform an electrophysiological study of central areolar choroi dal dystrophy (CACD) in the affected members of a four generation family. M ethods: Eight affected family members from the last three generations of a family affected by CACD were assessed by full-field electroretinograms (rod response, maximal combined response, oscillatory potentials, single-hash c one response and 30Hz flicker responses) and electro-oculograms, In additio n three members of the youngest generation, who were visually asymptomatic, had pattern visual evoked potentials (PVEPs) and pattern electroretinogram s (PERGs) performed. Affected status had been determined previously by gene tic analysis. Results: Three youngest generation family members, who were c onsidered affected by genetic haplotype analysis, had no visible optic nerv e or retinal abnormalities. All of these subjects had abnormal PVEPs and PE RGs in both eyes. Abnormalities were also detected in two of these subject' s Rod ERGs, Cone ERGs and one of these subject's Maximal ERGs and 30Hz ERGs . Electrophysiological examination in the older generations demonstrated a similar, more advanced, cone and rod dysfunction. Conclusions: All affected , but clinically normal, youngest generation patients had bilaterally abnor mal PVEPs and PERGs. In CACD the PVEP and PERG proved to be the most sensit ive electrophysiological tests of preclincial macular dysfunction, 3/3 subj ects abnormal. ERG recording to ISCEV guidelines were very useful in these cases; 7/8 subjects abnormal. The EOG was less useful; 4/8 subjects abnorma l. CACD produces a widespread photoreceptor dysfunction in its later stages .