Electroretinographic Findings in Patients with Branch Retinal Vein Occlusion

To evaluate the electroretinographic findings in cases of branch retinal vein occlusion(BRVO), Electroretinogram(ERG) were performed according to ISCEV(International Society for Clinical Electrophysiology of Vision) protocol in 17 unilateral BRVO patients. According to fluorescein angiographic acute stage group, hemorrhagic area of fundus was evaluated from retinal photo obtained by fundus camera. And correlation between hemorrhagic area and ERG was evaluated In acute stage group, the b-wave amplitude and b/a ratio of scotopic maximal combined response and oscillatory potential were significantly decreased at the affected eye compared unaffected eye. These findings were not found in chronic stage group. The relationship between hemorrhagic area and ERG finding was not detected in acute stage group. ERG findings in the acute stage of BRVO show that main pathologic lesion of BRVO is located in the inner retinal layer and inner retinal circulation. With further follow-up study, It is possible to use ERG data as a predictor of the course of BRVO.

The Effects of Calcium Dobesilate(Doxium) on the Electroretinogram in Patients with Diabetic Retinopathy

The purpose of the study is to evaluate the effects of calcium dobesilate (Doxium) on the electroretinographic changes in 60 non-insulin dependent diabetic patients with mild to moderate diabetic retinopathy, randomly assigned to receive either oral calcium dobesilate l000mg twice 8 day for 6 months or without medication. And also the effects of blood HbAlc and retinal photocoaglulation on the electroretinographic changes were evaluated. All patients were tested electroretinography with UTAS-2000 (LKC co., USA) before treatment and six months later respectively. The time interval changes of the electroretinogram were analyzed with student t-test program. As a result, no interval changes of the electroretinographic b-wave amplitudes and b/a ratio were noted in both groups, but the oscillatory potentials were significantly decreased after 6 months in the non-treated group (p:0.002). As compared to calcium dobesilate treated group, the non-treated group with blood HbAlc over 6.5mg% (p:0.008) or treated with retinal photocoagulation (p:0.001) showed a significant decrease of the oscillatory potentials. In conclusion, the administration of calcium dobesilate in the patients with diabetic retinopathy prevents an oscillatory potentials reduction, especially in patients with blood level of HbAlc below 6. 5mg% or treated with retinal photocoagulation.

ERG b/a ratio and retinal circulation time of CRVO

Fourteen cases of central retinal vein occlusion (CRVO) were studied with electroretinogram (ERG) and fluorescein angiogram. The cases were divided into a venous stasis retinopathy group (VSR,9 cases) and a hemorrhagic retinopathy group(HR, 5 cases). The b/a ratio and retinal circualtion time (RCT) were measured and compared with the control group. The mean b/a ratio of the HR group (0.86) was decreased as compared with the VSR group (1.18) and the control group (1.23). The RCT of the HR group was markedly delayed to 13.68 seconds as compared with the VSR group (11.09 sec) and the control group (6.4 sec). These facts suggest that both the b/a ratio and the RCT are possible parameters for estimating retinal ischemia and that the ERG is a reliable examination method for classification of CRVO.