PU Conference Series: Euretina 2018

OCTA Assessment of Choroidal Perfusion Helps Patients with Diabetic Retinopathy Association documented between diminished flow in deeper macular networks and reduced EZ “normalized”.

I n patients with diabetic retinopathy, researchers have demonstrated an association between a diminished flow in the deeper macular microvas- cular networks and a reduced ellipsoid zone (EZ) “normalized” reflectivity. The study supports the concept that macular ischemia is a contributor to photoreceptor loss in diabetic retinopathy. “Eyes with non-proliferative diabetic retinopathy have macular hypoperfusion and photoreceptor damage,” co-author Leonardo Mastropasqua, MD, of the Ophthalmology Clinic at the University “G. D'Annunzio” of Chieti-Pescara in Abruzzo, Italy, said in an interview with Elsevier’s PracticeUpdate . “Importantly,” he added, “hypoperfusion is not limited to the retinal vessels, given that even the choroidal vessels were demonstrated to have a lower perfusion. Finally, diabetic choroidopathy (choroidal hypoperfusion) seems to be strongly associated with photoreceptor damage.” Diabetes may impair visual function in several ways, including macular edema, vitreoretinal hemorrhage, and vitreomacular disorders, Dr. Mastropasqua noted. “Furthermore, diabetic retinopathy is known to be characterized by vascular damage with hypoperfusion of the retinal and choroidal vasculature, resulting macular ischemia. This hypoperfusion is known to damage the structures of the macula, which may impair the visual function.” Optical coherence tomography angiography (OCTA), although still a rapidly evolving tech- nology, has proven to be a valuable tool for the depth-resolved evaluation of the retinal and cho- roidal circulation without the need for dye injection. In the study presented here, the research team investigated the relationship between macular ischemia and photoreceptor damage in eyes with non-proliferative diabetic retinopathy to help shed further light on the relationship between vascular parameters and photoreceptor damage in these eyes. “This could be helpful to better understand the disease pathophysiology and to identify poten- tial biomarkers for disease progression and new

Dr. Leonardo Mastropasqua

targets for pharmacological treatment,” said Dr. Mastropasqua. Macular optical coherence tomography (OCT) and OCTA images were acquired from 18 patients (11 males, 7 females) with clinical evidence of diabetic retinopathy. Nine eyes were affected by mild non- proliferative diabetic retinopathy (NPDR), 3 eyes had moderate NPDR, 4 eyes had severe NPDR, and 2 eyes had proliferative diabetic retinopathy. There were four main outcome measures. These included superficial retinal capillary plexus (SCP), intermediate retinal capillary plexus (ICP) and deep retinal capillary plexus (DCP) perfusion density based on the area of vessels as well as SCP, ICP, and DCP vessel length density based on a map with vessels of 1-pixel width. Choriocapillaris (CC) perfusion density was also measured along with the “normalized” reflectivity of the (EZ) en face image. The latter, the authors noted in their abstract, represents a surrogate for photoreceptor damage. The ICP, DCP, and EZ beneath hyperreflective foci within retina, as well as under superficial retinal vessels, were excluded from the final assessment to avoid shadowing or projection artifacts from confounding the analysis. Normalized EZ reflectivity was correlated with ICP perfusion and vessel length density (P = .005 and P = .046, respectively), DCP perfusion and vessel length density (P = .012 and P = .039), and CC perfusion density (P = .037). In multiple regression

PRACTICEUPDATE CONFERENCE SERIES • EURETINA 2018 10