Marques, Inês P.Kubach, SophieSantos, TorcatoMendes, LuísMadeira, Maria H.Sisternes, Luis deTavares, DianaSantos, Ana RitaLewis, WarrenLobo, ConceiçãoDurbin, Mary K.Cunha-Vaz, José2021-07-232021-07-232021-05-24Marques, I. P., Kubach, S., Santos, T., Mendes, L., Madeira, M. H., de Sisternes, L., Tavares, D., Santos, A. R., Lewis, W., Lobo, C., Durbin, M. K., & Cunha-Vaz, J. (2021). Optical Coherence Tomography Angiography Metrics Monitor Severity Progression of Diabetic Retinopathy—3-Year Longitudinal Study. Journal of Clinical Medicine, 10(11). https://doi.org/10.3390/jcm101122962077-0383http://hdl.handle.net/10400.22/18162To examine retinal vessel closure metrics and neurodegenerative changes occurring in the initial stages of nonproliferative diabetic retinopathy (NPDR) and severity progression in a three-year period. Three-year prospective longitudinal observational cohort of individuals with type 2 diabetes (T2D), one eye per person, using spectral domain-optical coherence tomography (SD-OCT) and OCT-Angiography (OCTA). Eyes were examined four times with one-year intervals. OCTA vessel density maps of the retina were used to quantify vessel closure. Thickness of the ganglion cell + inner plexiform layer (GCL + IPL) was examined to identify retinal neurodegenerative changes. Diabetic retinopathy ETDRS classification was performed using the seven-field ETDRS protocol. A total of 78 eyes/patients, aged 52 to 80 years, with T2D and ETDRS grades from 10 to 47 were followed for 3 years with annual examinations. A progressive increase in retinal vessel closure was observed. Vessel density (VD) showed higher decreases with retinopathy worsening demonstrated by step-changes in ETDRS severity scale (p < 0.001). No clear correlation was observed between neurodegenerative changes and retinopathy progression. Conclusions: Retinal vessel closure in NPDR correlates with DR severity progression. Our findings provide supporting evidence that OCTA metrics of vessel closure may be used as a surrogate for DR severity progression.engOCTADiabetesRetinopathySeverityIschemiajournal article10.3390/jcm10112296