Adaptive optics optical coherence tomography (AO-OCT) provides depth resolved images of the retina with cellular resolution [1, 2]. So far, various cell types have been visualized with this technique including rod photoreceptors , retinal pigment epithelium cells [3, 4] or Ganglion cells [5, 6]. However, a translation of this technology into clinical settings remains challenging as AOOCT systems are quite bulky and complex to operate. In addition, the clinical benefit of AO-OCT imaging has not yet been demonstrated as especially elderly patients are difficult to image. This presentation gives an overview over the performance of AO-OCT technology in a clinical setting.
In this work we investigate the benefits of using optical coherence tomography angiography (OCTA) in combination with adaptive optics (AO) technology. It has been demonstrated that the contrast of vessels and small capillaries can be greatly enhanced by the use of OCTA. Moreover, small capillaries that are below the transverse resolution of the ophthalmic instrument can be detected. This opens unique opportunities for diagnosing retinal diseases. However, there are some limitations of this technology such as shadowing artifacts caused by overlying vasculature or the inability to determine the true extension of a vessel. Thus, the evaluation of the vascular structure and density can be misleading. To overcome these limitations we applied the OCT angiography technique to images recorded with AO-OCT. Due to the higher collection efficiency of AO-OCT in comparison with standard OCT an increased intensity contrast of vasculature can be seen. Using AO-OCTA the contrast of the vasculature to the surrounding static tissue is further increased. The improved transverse resolution and the reduced depth of focus of the AO-OCT greatly reduce shadowing artifacts allowing for a correct differentiation and segmentation of different vascular layers of the inner retina. The method is investigated in healthy volunteers and in patients with diabetic retinopathy.