Polarization-sensitive optical coherence tomography can be used to measure the birefringence of biological tissue such as the human retina. Previous measurements with a time-domain polarization-sensitive optical coherence tomography system revealed that the birefringence of the human retinal nerve fiber layer is not constant, but varies as a function of location around the optic nerve head. Her...

PURPOSE To evaluate the effect of age on optic nerve axon counts, spectral-domain optical coherence tomography (SDOCT) scan quality, and peripapillary retinal nerve fiber layer thickness (RNFLT) measurements in healthy monkey eyes. METHODS In total, 83 healthy rhesus monkeys were included in this study (age range: 1.2-26.7 years). Peripapillary RNFLT was measured by SDOCT. An automated algori...

Methods: Optical coherence tomographic images from 60 subjects (20 with ODE, 20 with ONHD, and 20 control subjects) were assessed qualitatively and quantitatively. Qualitative criteria for ODE included an elevated optic nerve head with smooth internal contour and subretinal hyporeflective space (SHYPS) with recumbent “lazy V” pattern. Optic nerve head drusen displayed a “lumpybumpy” internal op...

The objective of this paper is to offer experimental evidence which shows that the process of excitation in the nerve is accompanied by a transient change in optical properties of the nervous tissue. The optical properties examined include fluorescence, turbidity, and birefringence. Changes in fluorescence were examined after nervous tissues were stained with the dye 8-anilinonaphthalene-1-sulf...

Glaucoma is characterized by a combination of structural changes in the retina and optic nerve head and functional perimetric damage. Examination and documentation of the retinal nerve fiber layer are essential for the diagnosis and monitoring of glaucoma. Spectral domain Optical coherence tomography (OCT) is a high resolution imaging device capable of obtaining reproducible retinal nerve fiber...

Introduction: For many years, amblyopia was regarded as a disorder of the visual system in which an organic cause could not be identified. Optical Coherence Tomography opens new horizons in understanding the etiopathology of amblyopia and seems to highlight morphologic anomalies in the retina of the amblyopic eye. Purpose: The objective of this paper is to analyze the macular thickness, optic n...

Previously we have reported a near-infrared optical response in the region occupied by a peripheral nerve that is distal to the site of electrical stimulation of that peripheral nerve. This "intermediate" signal is vascular in nature but its biological origin not been elucidated. In the present study, an animal model of the signal has been created and our human studies expanded to directly inve...

Peripheral nerve injuries remain a challenge for reconstructive surgeons with many patients obtaining suboptimal results. Understanding the level of injury is imperative for successful repair. Current methods for distinguishing healthy from damaged nerve are time consuming and possess limited efficacy. Confocal laser endomicroscopy (CLE) is an emerging optical biopsy technology that enables dyn...

Nerve block can eliminate spasms and chronic pain. Kilohertz frequency alternating current (KHFAC) produces a safe and reversible nerve block. However, KHFAC-induced nerve block is associated with an undesirable onset response. Optical inhibition using infrared (IR) laser light can produce nerve block without an onset response, but heats nerves. Combining KHFAC with IR inhibition [alternating c...

The detection of individual action potentials in nerve cells via intrinsic optical signals could open a new modality for the analysis of cellular properties in spatially extended cells and emergent properties in networks of neurons. Here we review the experimental evidence for the detection of changes in intrinsic optical properties, i.e., changes in optical refractive index, that covary with c...