Purchase this article with an account.
Louisa Wickham, Abdul-Kadir Karim, Mostafa Elgohary, Kam Ballagan, Raymond Moss, Maria Firth, Gary Firth, Graham Thompson; A comparison of Water Soluble Antioxidants in Human Vitreous Humour in Retinal Ischaemia. Invest. Ophthalmol. Vis. Sci. 2014;55(13):1351.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To estimate the levels of water soluble antioxidants, ascorbate and uric acid in patients with retinal ischaemia from samples taken at the time of vitrectomy.
104 patients undergoing primary vitrectomy were recruited from a vitreoretinal clinic at the time of listing for surgery. Patients were classified according to whether retinal ischaemia was present. A blood sample was taken from patients just prior to the commencement of surgery. A dry core vitreous sample was then taken at the start of surgery. A full drug history, including vitamin supplementation was taken from all patients.
Of the 45 patients classified as ischaemic, 38 were diabetic. In the non-ischaemic group (N = 59) the main indications for surgery were macular hole (N=33) and epiretinal membrane (N=14). The mean age at the time of surgery was 68 years (interquartile range (IQR) 63 - 77) in the non-ischaemic group and 59 years (IQR 49-69) in the ischaemic group. Levels of ascorbate were significantly reduced in the vitreous (p<0.001) and plasma (p<0.001) of patients with retinal ischaemia. There was no significant difference in the number of patients taking vitamin supplements containing ascorbate between the 2 groups (Χ2= 1.2, p=0.265). Vitreous (p<0.001) and plasma (p=0.04) levels of uric acid were significantly increased in patients with retinal ischaemia.
Vitreous levels of ascorbate are decreased in patients with retinal ischaemia and this may reflect it’s antioxidant role in these patients. It is likely that plasma levels of ascorbate are similarly reduced due to mobilisation by active transport across the concentration gradient into the vitreous. Uric acid levels have been reported to be higher in patients with retinal ischaemia, a finding that was repeated in this study.
This PDF is available to Subscribers Only