Abstract
Abstract: :
Purpose: To investigate the ability of ultrahigh resolution optical coherence tomography (OCT) to discriminate the microscopic anatomy of the human retina and to compare ultrahigh resolution OCT measurements to histomorphometry in the same normal and diseased human eye. Methods: Imaging was performed using a third generation ultrahigh resolution OCT system with a femtosecond laser light source which generates bandwidths of 300 nm at 800 nm center wavelength. This broadband light source enables ultrahigh resolution OCT imaging with 2-3 µm axial resolution in air. Cadaver human eyes were obtained from NDRI or NEMC and were scanned within 48 hours of death and fixed in a 3% glutaraldehyde solution. To minimize subretinal fluid perfluorocarbon solution was used after sectioning the eye to flatten the retina. The retinal thickness was measured directly on the OCT scans. The corresponding histomorphometry was performed using a Nikon Elipse E400 microscope and retinal thicknesses were measured. Results: Ultrahigh resolution OCT and histomorphometry produced similar data for retinal thickness in normal and glaucomatous eyes. Retinal layers, including the nerve fiber layer, inner nuclear layer, outer nuclear layer, the retinal pigment epithelium, choriocapillaris and choroids could be distinguished. There were differences in retinal thickness between normal and glaucomatous eyes by both ultrahigh resolution OCT and histomorphometry. Conclusion: Ultrahigh resolution OCT imaging differentiates retinal layers similar to those seen by light microscopy both qualitatively and quantitatively in both normal and diseased human eyes.
Keywords: 432 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound) • 554 retina • 498 optic disc