Abstract
Abstract: :
Purpose: To demonstrate ultrahigh resolution optical coherence tomography’s (OCT) ability to image morphological retinal diseases processes and improve quantitative measurements of retinal features. Methods: A third generation, ultrahigh resolution ophthalmic OCT system has been developed using a femtosecond laser generating bandwidths of up to 300 nm at 800 nm center wavelength. This OCT system enables imaging of the retina with less than 3 µm axial resolution. Significant improvement in the system scanning speed allows high transverse pixel densities of 400 to 600 axial scans. This enables real-time cross-sectional imaging of retinal morphological architecture in patients with macular disease and glaucoma. Expert edge detection and segmentation algorithms were developed to quantify retinal and intraretinal morphology. OCT is compared to ophthalmoscopic examination, fluorescein angiography and visual field. Results: OCT imaging with axial resolutions of less than 3 µm has been performed in eyes of patients with various retinal diseases. OCT imaging at this resolution enables the visualization of intraretinal morphology such as the ganglion cell layer, plexiform layers, as well as the nerve fiber layer. Quantitative measurements of retinal features associated with pathology were obtained using the ultrahigh resolution OCT and compared with measurements taken with the standard resolution (10-15 µm) commercial OCT system. The improved axial resolution and pixel density of the ultrahigh resolution OCT system enables better differentiation and more accurate measurements of retinal pathology associated with diseases such as glaucoma, diabetic retinopathy, and macula diseases. Conclusion: Ultrahigh resolution ophthalmic OCT enables non-invasive in vivo visualization of intraretinal morphology associated with retinal diseases. The increased resolution of the ultrahigh resolution OCT system over the standard commercial OCT system facilitates more accurate measurements of retinal ultrastructure. The improved ability to detect changes in retinal pathology promises to improve the early diagnosis of a variety of ocular diseases such as glaucoma, diabetic macular edema, or age-related macular degeneration.
Keywords: 432 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • 430 imaging/image analysis: clinical • 431 imaging/image analysis: non-clinical