Abstract
Purpose: :
Adaptive optics-optical coherence tomography (AO-OCT) is a new imaging modality that combines the high axial resolution of Fourier-domain OCT (FD-OCT) with high transverse resolution of adaptive optics (AO). In this study, we compared the morphologic information obtained with AO-OCT to that obtained with FD-OCT for various subtle and unexplained macular pathologies.
Methods: :
Patients with subtle maculopathy (diagnosed on funduscopy, fluorescein angiography and commercial FD-OCT) and/or with unexplained visual symptoms were imaged with AO-OCT and FD-OCT developed at our institution. The AO-OCT system has axial and transverse resolutions of 3 microns. It was used to zoom into macular regions of interest for detailed examination. The FD-OCT system has axial resolution of 4.5 microns and transverse resolution of 10 to 15 microns. Scans centered on the fovea were obtained and compared to images obtained using AO-OCT.
Results: :
AO-OCT revealed additional micro-structures as well as more structural details that were not detected by conventional imaging systems and high resolution FD-OCT. These structures included fine intraretinal structural changes such as subtle intraretinal deposits or disruption of retinal layers. Of special interest is a case of mild bilateral juxtafoveal telangectasia diagnosed by fluorescein angiography. Her unexplained visual symptoms had no apparent morphological basis, except with AO-OCT imaging which revealed subtle deposits in the Fibers of Henle.
Conclusions: :
This study demonstrated that AO-OCT has sufficient resolution to detect subtle microstructural changes associated with various macular pathologies that were not evident with other imaging systems including high resolution FD-OCT. AO-OCT may be a useful tool for furthering our understanding of various macular pathologies.
Keywords: imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • photoreceptors • retina