Slow and Fast Oscillation Electrooculography in Central Retinal Vein Occlusion: A Comparison between Affected Eyes and Fellow Intact Eyes

Using an automated electrooculograph, the Nidek EOG-2, slow and fast oscillations (SO and FO) of an electrooculogram (EOG) were recorded in 21 patients with unilateral, ischemic central retinal vein occlusion (CRVO). Patient age ranged from 49 to 81 years (average: 68 years of age). Fellow eyes in all patients were intact, and served as controls. Results showed that the L/DSO (the light peak/dark trough ratio of the SO), the Rf FO [the average ratio in percentage of the maximum amplitude in the dark period (AD)/the minimum amplitude in the light period (AL) during FO measurement], the df FO (the average difference in µV between AD and AL), and the df/mFO [the percentage ratio of the df FO to the average amplitude of AD + AL (m)] were significantly decreased in the affected eyes compared with the fellow eyes. These results suggest that with regard to SO and FO origin and occurrence, the outer layer of the retina, especially the basal membrane of the retinal pigment epithelium or the choroid may be involved in the etiology of CRVO. These findings correlate with the grade of microcirculatory disturbance or ischemia in the inner layer of the retina. Furthermore, a statistically significant difference was detected in the correlation between each FO parameter and corrected visual acuity at the time of examination of the affected eyes. There was no significance between the SO parameter and the visual acuity. Therefore, it might be possible to presume that the FO parameters can be used as indicators for detecting the severity of macular functional disturbance and predicting the visual outcome for this entity.