Comparison between two wide-field imaging systems on the extent of retinal periphery area viewing – Short title: comparison of wield-field imaging

Fundus imaging has become an integral tool in retinal diagnosis. Although single- field fundus photography covers a vital region of the retina, it leaves a large portion of the periphery undiscovered. The wide-field imaging system showed its superiority in early detection of lesions determined by diabetic retinopathy, especially as a screening tool for high-risk patients. In Austria, there are two different wide-field imaging systems available. The first device on the market was the Optos (Optos PLC, Dunfermline, UK) and several years later the Clarus 500 (Carl Zeiss, Meditec AG, Jena, Germany) was introduced. The aim of the study is to compare two CE-marked imaging systems concerning the extent of retinal periphery area viewing.