Visual field loss in glaucoma is the result of damage to the RGCs. Cellular basis for the field of visionĭetection of visual stimuli relies on an intact neural pathway beginning with retinal photoreceptors, and then proceeding through bipolar cells, retinal ganglion cells (RGC), and brain neurons extending from the lateral geniculate to the occipital cortex. At this location, no photoreceptors are present, creating a normal absolute scotoma. Nerve fibers pass through the sclera at the optic nerve head, typically 10-15º nasal to fixation. The field of vision is often depicted as a three dimensional hill, with the peak sensitivity to stimuli occurring at the point of fixation under photopic conditions, decreasing rapidly in the 10º around fixation, and then decreasing very gradually for locations further in the periphery. From the point of fixation, stimuli can typically be detected 60º superiorly, 70º inferiorly, 60º nasally, and 100 degrees temporally, though the true extent of the visual field depends on several features of the stimulus (size, brightness, motion) as well as the background conditions. The normal eye can detect stimuli over a 120º range vertically and a nearly 160 degree range horizontally. The field of vision Normal field of vision Advances in computer technology have facilitated more sensitive and reproducible visual field loss detection than was possible with manual perimetry, allowing clinicians to detect glaucoma earlier in its course and to monitor loss quantitatively over time. This review will focus primarily on standard automated perimetry (SAP). Visual field testing can be performed by various methods, including confrontation technique, Amsler grid, tangent screen, kinetic perimetry, or static perimetry. Visual function assessment is integral to the evaluation and management of glaucoma. 4.3 Identifying Glaucomatous VF Loss on SAP.4.2 Establishing reliability of results.4.1.3 Summary measures of visual field performance.4.1.2 Displays of sensitivities across the visual field. ![]() 3.7.2 Frequency doubling technology (FDT).3.7.1 Short-wavelength automated perimetry (SWAP).3.4.3 Swedish Interactive Threshold Algorithm (SITA).2.4 Characteristics of visual field loss in glaucoma.2.3 Retinal nerve fiber paths and the field of vision.2.2 Cellular basis for the field of vision.
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