ELECTROOCULOGRAPHIC ABNORMALITIES IN AMBLYOPIA

Background-Electrodiagnostic tests have been used to investigate retin al function in amblyopia but previous results have been conflicting. M ethods-It was decided to investigate whether the electro-oculogram (EG G) showed any abnormalities in 12 adult amblyopes and 12 age and sex m atched controls with normal vision. The mean amplitudes of the EOG rec ordings from each eye during 12 minutes of darkness and 18 minutes of light were compared. Results-The mean values amblyopic eyes were lower from the fellow non-amblyopic eyes. At most time points the differenc e was significant (p<0 05). After normalisation of the data to minimis e intersubject variation, the reduction in EOG amplitudes of the ambly opic eyes at all time points was significant (p<0 05). There was no si gnificant difference between the mean values obtained from the right a nd left control eyes at any time point, either before or after normali sation. Conclusion-These results provide evidence for a retinal abnorm ality in amblyopia and implicate the retinal pigment epithelium as bei ng involved. A deficiency in retinal dopaminergic function in amblyopi a is proposed as a possible mechanism causing these results.