In the present study, structures in retinal inner and outer plexiform layers, subretinal layer, optic nerve head, and cornea were all consistently identified by morphological identification utilizing planar projections of their three-dimensional structures. In the case of the retinal capillaries in the inner and outer plexiform layers, the finding may be counterintuitive to those experienced in retinal OCT imaging. In on the nasal (upper right) optic nerve head, large vessels appear as black ovals. Indeed, blood moving in large vessels results in a loss of back-scattering signal due to fringe washout [20
]. But in the present study, the slow moving blood within retinal capillaries produced a high intensity back-scatter signal relative to the surrounding tissue (, arrows). The fact that slow moving or stationary blood produces a strong OCT signal implies that the bright circle surrounding the black center of large blood vessels is slow moving blood near the vessel edge, and not the vascular lumen ().
In (upper left), it appears that blood within the choriocapillaris did not create a reflective signal. The lack of reflectance may suggest that, similar to blood in large retinal vessels, the blood within the choriocapillaris is moving so fast that fringe washout renders back-scattered light immeasurable with the present system. Inverting the data volume black/white provides visualization of the lack of back-scattered light, yielding an image reminiscent of previous vascular casting studies of the choroid.
Cross-sectional imaging of laminar pores may be clinically useful in the future, but the subjective examination of laminar pore size and distribution is currently considered in the management of glaucoma. demonstrates that lamina cribrosa pores can be visualized by focusing deep within the optic nerve head, and isolating the layer within a C-mode slab. The distribution and size of pores within the lamina cribrosa are each more readily visible in the C-mode slab than in the optic disc photo, suggesting that visualization of pores located beneath nerve fiber tissues is feasible with SdOCT.
In the corneal image, a highly reflective structure () is observed extending from the limbus into the cornea. (, top) Given the avascular nature of the cornea, it is possible that these are cornea nerves. The low intensity of the secondary structure was due to slight displacement from the location of the C-mode used. Slight anterior relocation of the C-mode slab caused a number of nerves not readily visible in the cross-sectional series to come into view (, bottom).