[New Possibilities in Retinal Diagnostics Using OCT Angiography]

Instruments for using OCT angiography (OCTA) in daily clinical practice have recently become available. The aim of this paper is to report the possibilities, advantages and limitations of OCTA in the clinical diagnosis of diseases of the posterior segment of the eye.

Patients with diabetic retinopathy, retinal vascular occlusions, and age-related macular degeneration who had been assigned to fluorescein angiography (FA) additionally underwent an AngioPlex™-OCTA examination, which captures a 6 × 6 mm scanning area centred on the fovea. If deemed necessary, 3 × 3 mm volume scans were created in regions of interest. The findings of FA and OCTA were correlated and compared.

The OCTA procedure took only a few seconds, was easily integrated into the standard OCT diagnostic imaging procedure, and delivered highly detailed, three dimensional images of the entire microvasculature of the retina and choroid. Microvascular changes, such as microaneurysms, intraretinal microvascular abnormalities, non-perfused areas, alterations in the foveal avascular zone (FAZ) and neovascularization were reliably detected. Overall, OCTA results were in good agreement with the results of the FA. Additionally, OCTA provided more detailed and three dimensional information and thus permitted a better assessment of the spatial extension of microvascular abnormalities. Due to OCTA's limited scanning area, vascular alterations in the mid-periphery were detected only if their location had already been determined by FA. Although OCTA does not show leakage, macular oedema can be diagnosed from OCTA, together with OCT thickness measurements.

OCTA provides important three dimensional information on vascular alterations and is already an indispensable diagnostic method. As the procedure takes just a few seconds and can be performed non-invasively, OCTA is well suited as a monitoring method and may allow early diagnosis. In this sense, prospective studies are required to determine precise OCTA analytical strategies for specific diseases. It is very likely that OCTA will revolutionise the diagnosis of retinal and choroidal diseases; however, it is not yet clear estimated to what extent it will replace FA.