PRESENCE OF PERIPHERAL LESIONS AND CORRELATION TO MACULAR PERFUSION, OXYGENATION AND NEURODEGENERATION IN EARLY TYPE II DIABETIC RETINAL DISEASE.

PURPOSE: The impact of peripheral retinal lesions (PL) visualized with ultra-wide-field imaging on diabetic retinopathy (DR) remains unclear. The purpose of this study was to assess the presence of PL and their association with macular microvasculopathy, metabolic dysfunction, and neurodegeneration in patients with Type II diabetes and early retinal disease. METHODS: Forty-five degree color fundus (Topcon) and 200° ultra-wide-field images (Optos) were assessed for the presence and severity of DR. Lesions anterior to the 45° were considered peripheral. The foveal avascular zone area, perimeter and acircularity index, and foveal full-retina and parafoveal superficial/deep complex vessel density were evaluated with RTVue optical coherence tomography angiography. Vessel oxygen saturation was measured with oximetry. Peripapillary retinal nerve fiber and individual macular retinal layer thicknesses were measured with Spectralis optical coherence tomography. RESULTS: Among the 161 eyes (80 left eyes) of 81 patients (34 female), 64 (39.8%) showed higher levels of DR on ultra-wide-field than on 45° fundus images (P < 0.0001). PL were identified in 97 eyes (60.3%) and in 59 among 115 eyes without central signs of DR. No significant correlation to biomarkers of central microvascular disease (foveal avascular zone/vessel density variables), oxygen saturation, and retinal layer thickness was found. CONCLUSION: Ultra-wide-field imaging helps to detect more eyes with early DR due to the detection of PL, which appear independently of biomarkers of macular microvascular impairment, metabolic function, and neuropathy in eyes without central signs of DR. These results suggest that the evaluation of the retinal periphery may become crucial in DR screening if PL are proven to influence disease outcomes.