![]() ![]() The main techniques for clinical examination of the ONH include direct ophthalmoscopy, indirect ophthalmoscopy, and slit-lamp biomicroscopy with a contact lens or non-contact handheld lens (+66, +78, +90 diopter ) or a Hruby lens. the loss of lines belong to RNFL in red-free illumination (Figures 1A and B, and 2A–F).the changes in peripapillary region (ONH hemorrhages, peripapillary atrophy ) and.the presence of the laminar dot sign in the cup.the shape and configuration of the vessels in the ONH.the size, color, and integrity of the neuroretinal rim (NRR).In the examination of the ONH, the size and shape of the optic disc should be correctly evaluated, as should: However, firstly it is crucial to know what the features and appearance of a healthy optic disc should be. 10,11 Thus, the correct and careful evaluation of the optic disc and tissues immediately surrounding the disc are very important for detecting early glaucomatous damage. 7–9 It is understood that glaucomatous VF defects can be detected on standard automated perimetry when 20–40% of RGCs are lost. Glaucomatous optic nerve damage usually occurs in the ONH before there are any detectable visual field (VF) defects however, some studies have demonstrated that VF defects can also be found without any glaucomatous changes in the optic disc. ![]() 1–6 Therefore, we actually observe the superficial RNFL and the optic cup in the ONH. Although there are no clear lines demarcating the histologic layers of ONH, the ONH consists of the surface retinal nerve fibre layer (RNFL), and pre-laminar, laminar (lamina cribrosa ), and retrolaminar layers. 1–3 Although the ONH and the optic disc are often used to mean the same thing, in fact the optic disc is the part of the ONH which is observed in ophthalmoscopy. The primary site for glaucomatous damage is the ONH. Glaucoma is a progressive optic neuropathy characterized by the loss of retinal nerve fibres and the axons of RGCs at the level of the ONH. It also consists of blood vessels, glial, and connective tissue. The optic nerve head (ONH) is the region where retinal ganglion cells (RGCs) leave the eyeball via the scleral canal. Glaucoma, diagnosis, optic nerve head, optic This guide canįacilitate the diagnosis and exclusion of glaucoma in these subjects. The purpose of this review is to provide a guide to clinicians for the evaluation of the optic disc in glaucoma suspects and patients. However, some studies have demonstrated that visual field defects can also be found without any glaucomatous changes in the optic disc. The correct evaluation of the optic disc, and related structures in ophthalmoscopy, is critical for the diagnosis of open angle glaucomaīecause usually glaucomatous optic nerve damage firstly occurs in the optic disc before detectable visual field defects become apparent ![]()
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