Retinal nerve fiber layer thickness map determined from optical coherence tomography images

Abstract

We introduce a method to determine the retinal nerve fiber layer (RNFL) thickness in OCT images based on anisotropic noise suppression and deformable splines. Spectral-Domain Optical Coherence Tomography (SDOCT) data was acquired at 29 kHz A-line rate with a depth resolution of 2.6 mum and a depth range of 1.6 mm. Areas of 9.6x6.4 mm2 and 6.4x6.4 mm2 were acquired in approximately 6 seconds. The deformable spline algorithm determined the vitreous-RNFL and RNFL-ganglion cell/inner plexiform layer boundary, respectively, based on changes in the reflectivity, resulting in a quantitative estimation of the RNFL thickness. The thickness map was combined with an integrated reflectance map of the retina and a typical OCT movie to facilitate clinical interpretation of the OCT data. Large area maps of RNFL thickness will permit better longitudinal evaluation of RNFL thinning in glaucoma.