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Updated: Jul 25, 2026

Measurement of Factor V Activity in Human Plasma Using a Microplate Coagulation Assay
Published on: September 9, 2012
Factor VII deficiency in a patient with retinal arteriolar tortuosity syndrome
1Department of Ophthalmology, Assaf Harofeh Medical Center, Zerifin, Israel.
Purpose:
To report a pedigree with hereditary retinal arteriolar tortuosity with macular haemorrhage and abnormality of the coagulation system.
Methods:
Case report and literature review.
Results:
A 49-year-old woman was referred due to macular haemorrhage in both eyes. Her 16-year-old son had recurrent retinal haemorrhages which presented at age 16 years and had mild retinal arteriolar tortuosity. Coagulation studies in the son revealed normal activated partial thromboplastin time (APTT), prolonged prothrombin time (PT) and 30% activity of factor VII.
Conclusions:
Factor VII deficiency may aggravate the haemorrhages in retinal arteriolar tortuosity syndrome. We therefore suggest conducting routine coagulation studies (PT, APTT) in all patients with retinal arteriolar tortuosity syndrome. Determination of factor VII activity is warranted only in patients with normal APTT and prolonged PT.
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