Abstract
Abstract: :
Purpose: Abnormal levels of factor VIII are associated with thrombophilic disorders such as venous thrombosis. In addition, a thrombophilic tendency may be demonstrated by thromboelastography. The purpose of this study was to measure the level of factor VIII and examine the thromboelastograms (TEG) of patients presenting with branch retinal vein occlusions (BRVO) in order to demonstrate whether a thrombophilic tendency is present in these patients. Methods: Venesection was carried out on 14 consecutive patients presenting to a medical retina clinic with BRVO and the levels of factor VIII measured and compared with levels in the normal population. A TEG was performed within the hour and results compared to 14 coronary artery bypass graft (CABG) patients who acted as age-matched controls. Results: 9 of 14 patients (64%) with BRVO had Factor VIII levels higher than the upper limit of normal. On thromboelastography, the mean maximum amplitude in BRVO patients 61.79 mm (SE +/- 1.30) was statistically significantly greater than in CABG patients 57.39mm (SE +/- 1.31) (paired T test, p<0.02). Conclusion: The results show that a significant proportion of patients presenting with BRVO have increased levels of circulating factor VIII, and increased maximum amplitude of thromboelastograms, indicating a thrombophilic tendency. Hemorheologic abnormalities may be a significant factor in the aetiology of retinal venous occlusions.
Keywords: 554 retina • 615 vascular occlusion/vascular occlusive disease