For many years, the standard method of measuring the visual dysfunction that occurs with glaucomatous injury has been assessment of the visual field with perimetry, which measures differential light sensitivity, or the ability of the subject to detect a stimulus on a uniformly illuminated background.
Perimetry serves 2 major purposes in the management of glaucoma:
identification and quantification of abnormalities in the visual field
longitudinal assessment to detect glaucomatous progression and measure rates of change
Quantitation of visual sensitivity enables detection of visual field defects by comparison with normative data. Regular visual field testing in known cases of disease provides valuable information for helping to differentiate between stability and progressive loss.
Automated static perimetry is currently the standard method for assessing visual function in glaucoma. With this method, sensitivity measurements are performed at a number of test locations using white stimuli on a white background (“white on white”); this is known as standard automated perimetry (SAP), or achromatic automated perimetry. Automated perimetry offers obvious advantages compared with manual perimetry; in automated perimetry, stimulus presentation, as well as the recording of patient responses, can be standardized, which leads to results that are more reproducible. Therefore, manual kinetic perimetry is now rarely performed for visual field assessment in glaucoma. However, kinetic perimetry may be helpful for monitoring visual fields in patients who are unable to perform the automated test. Some perimeters are capable of performing automated kinetic perimetry, although its value for assessing visual field loss in glaucoma is not well established.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.