Abstract
Purpose :
To investigate optic disc perfusion changes in diabetic patients in relation to severity of the diabetic retinopathy using OCT Angigraphy Perfusion Density Mapping.
Methods :
A prospective observational study of 19 eyes with diabetic retinopathy with no history of glaucoma and 19 age-matched normal eyes was performed at the New York Eye and Ear Infirmary of Mount Sinai. Optic disc regions was imaged using spectral domain optical coherence tomography (OCT) (Optovue XR Avanti, Fremont, CA) and analyzed with the split-spectrum amplitude decorrelation angiography(SSADA) algorithm. Capillary perfusion density was calculated inside the optic nerve head and in the peripapillary region (defined as the 0.75mm width ring extending from the margins of the optic disc). The Wilcoxon–Mann–Whitney test was used to analyze the data and to compare the different groups.
Results :
Diabetic retinopathy patients were grouped according to severity, 10 patients had non-proliferative diabetic retinopathy (NPDR) and 9 patients had proliferative diabetic retinopathy (PDR). Capillary perfusion density values, both peripapillary and inside the disc, were significantly lower in nearly all patients with diabetic retinopathy compared to the normal controls. This was statistically significant with a p-values of 0.00466 and 0.0002 respectively using the Wilcoxon–Mann–Whitney test. This was also visible on the OCT angiography as there were significant capillary drop outs in the vascular network around the discs in the study patients compared to the controls. In addition, the NPDR group had a statistically significant higher perfusion density in the peripapillary region than the PDR group, but there was no difference in the perfusion density inside the optic nerve head. The p-values are 0.00614 and 0.72634 respectively.
Conclusions :
Diabetic retinopathy patients appear to have a lower optic nerve perfusion both inside the nerve head and in the peripapillary region compared to healthy controls. The observed correlation between the severity of the diabetic retinopathy and the optic nerve head perfusion which may explain the development of disc neovascularization. Additional studies with larger numbers may help clarify this relationship.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.