The OCT devices we work with are the Cirrus HD-OCT (Carl Zeiss Meditec Dublin, California), Spectralis (Heidelberg Engineering Heidelberg, Germany), and RTVue-100 (Optovue Fremont, California) we’ll refer to them throughout the article. Spectral-domain units are made by several manufacturers the devices differ in scanning protocols and segmentation algorithms, so their measurements are not easily interchangeable. 3 With side by side comparison, they were able to show that the reflectance patterns imaged by SD-OCT corresponded precisely to the various retinal layers.Ĭurrently, SD-OCT is the OCT device most commonly used in clinical practice. The correlation between anatomic structures and volumetric spectral domain-OCT images of the optic nerve head was made clear in a study by Nicholas Strouthidis, MD, and his colleagues at Devers Eye Institute, Oregon, when they performed SD-OCT imaging of the optic nerve head in monkeys and obtained thin histological sections of the same tissues. 2 In addition to cupping of the optic nerve, glaucoma patients often show sectorial loss of nerve fiber layer, which can be visualized with a red-free light. 1 In addition, the connective tissue in the ONH undergoes profound remodeling in glaucoma, leading to posterior deformation of the lamina cribrosa as well as expansion of anterior and posterior neural canal openings, as illustrated in an experimental monkey model of glaucoma. Green, MD, demonstrated that the increased optic disc cup size was caused by the loss of retinal ganglion cells and their axons. In 1979, Harry Quigley, MD, and William R. The axons exit the eye through the neural canal opening and are supported by the lamina cribrosa (essentially a connective tissue structure), which comprises the floor of the physiologic cup. The ONH is formed by the axons of the retinal ganglion cells, blood vessels and glial tissue. Glaucoma is characterized by loss of retinal ganglion cells and their axons, and by the remodeling of the optic nerve head, which manifests as neuroretinal rim narrowing, optic disc excavation and displacement of lamina cribrosa. Therefore, we’ll discuss the various tissue structures affected by glaucoma progression and then provide practical tips for using OCT to monitor them. One major advantage of OCT is its ability to show detailed, quantitative information about the various retinal layers, which corresponds to tissue sections on a histology slide. In this article, we’ll provide tips on how to use the OCT devices we’re familiar with to monitor progression, and how to avoid artifacts and other errors that can lead you astray. Although these remain key elements of the glaucoma evaluation, they’re still subjective and qualitative in nature, limiting their ability to detect progression reliably. Before the introduction of optical coherence tomography, determination of glaucoma progression relied heavily on clinical assessment of the optic nerve, comparison of disc photos over time and visual field analysis. 1856 10:170–93.S ince glaucoma is a progressive disease, physicians are constantly searching for reliable tools to monitor it over time. Zur pathologischen anatomic der netzaut und des scherven. Syndrome of myelinated retinal nerve fibers, myopia, and amblyopia: a review. Tarabishy AB, Alexandrou TJ, Traboulsi EI. Straatsma BR, Foos RY, Heckenlively JR, Taylor GN. Characteristics of myelinated retinal nerve fiber layer in ophthalmic imaging: findings on autofluorescence, fluorescein angiographic, infrared, optical coherence tomographic, and red-free images. Shelton JB, Digre KB, Gilman J, Warner JEA, Katz BJ. Acquired retinal myelination in neurofibromatosis 1. Development of myelin in human optic nerve and tract: a light and electron microscopic study. Myelinated retinal nerve fibers: prevalence, location and effect on visual acuity. Acquired and progressive retinal nerve fiber layer myelination in an adolescent. Jean-Louis G, Katz BJ, Digre KB, Warner JEA, Creger DD. The relation of the blind spot to medullated nerve fibers in the retina. Morphological consequences of myelination in the human retina. A sign of multiple basal cell nevi (Gorlin’s) syndrome. 2013 161(4):829–34.ĭe Jong PT, Bistervels B, Cosgrove J, de Grip G, Leys A, Goffin M. GAPO syndrome: four new patients with congenital glaucoma and myelinated retinal nerve fiber layer. Progression of retinal nerve fiber myelination in childhood. 1985 103:542–4.Īli BH, Logani S, Kozlov KL, Arnold AC, Bateman B. Acquired and progressive myelinated nerve fibers.

Nerve fiber layer of retina