Detecting papillary neovascularization in proliferative diabetic retinopathy using optical coherence tomography angiography

Diabetic retinopathy (DR) affects almost 30% of patients with diabetes mellitus (DM), and proliferative diabetic retinopathy (PDR) involves 9% of them with consequent severe visual impairment. Proliferative diabetic retinopathy (PDR) represents a heightened risk of life‐threatening systemic vascular complications and occurs due to glycaemic impairment and long periods of metabolic alterations. The natural evolution of PDR is characterized by a series of clinical signs, starting with retinal ischaemia and an abnormal activation of vascular endothelial growth factor (VEGF). This alteration leads to retinal neovascularization and the appearance of retinal haemorrhage, fibrosis and vitreous bleeding in the later stages of the disease. Although the neovascularization in PDR is detectable just by ophthalmoscopy, the advantage of fluorescein angiography (FA) is that it can identify capillary non‐perfusion and leakage area. Recently, a new method of retinal vessel analysis without dye injection has been introduced. Optical coherence tomography angiography (OCT‐A) is based on a split‐spectrum amplitude‐decorrelation angiography (SSADA) algorithm. This algorithm allows the detection and visualization of blood flow and morphology of retinal vessels, ischaemia with special emphasis on the retinal and papillary microvasculature. Nevertheless, OCT‐A cannot ascertain whether neovascularizations are leaking, and this technique is therefore also accompanied with information loss. The aim of this study was to evaluate whether OCT‐A provides better visualization of neovascularization of the optic disc (NVD) in patients with PDR than conventional FA.