Microperimetry in age: related macular degeneration

Abstract

Age-related macular degeneration (AMD) is one of the major causes of visual loss and legal blindness in people over 55. Visual function tests are the cornerstone of visual function investigation and any therapeutic approach to AMD implies, as primary endpoint, the maintenance or improvement of visual function. The progression of visual impairment and the quantification of final residual visual function are currently determined by means of visual acuity quantification. The quantification of high-contrast visual acuity though has many drawbacks and cannot be considered a complete functional examination. Microperimetry is a non-invasive method used to analyse fixation and central visual field defects in a topographic related manner. The introduction of mesopic and more recently scotopic microperimetry, in research and clinical practice of macular disorders, now allows us to better investigate macular function as it strictly relates to macular morphology. We therefore can monitor the functional natural history and quantify the beneficial or detrimental effects of different therapies. The application of microperimetry in clinical studies has provided interesting diagnostic and prognostic information on functional macular changes in AMD patients. The present review brings new updates on the correlation between macular changes, mainly described with optical coherence tomography, and microperimetry changes in patients with AMD.

Individual Test Point Fluctuations of Macular Sensitivity in Healthy Eyes and Eyes With Age-Related Macular Degeneration Measured With Microperimetry

“…Alternatively, or in combination with VA measurement, clinicians have increasingly used microperimetry to measure macular function. 3 – 7 The advantage of current commercially available microperimetry instruments is that they allow compensation for eye movements, and therefore a precise measurement of the same retinal location is possible. 8 This compensation certainly reduces the fluctuations of the test–retest sensitivity previously found in conventional automated perimetry.…”

Detection of Early Loss of Color Vision in Age-Related Macular Degeneration – With Emphasis on Drusen and Reticular Pseudodrusen

“…Psychophysical tests designed to measure stimulus-specific loss of visual sensitivity by determining the relationship between controlled visual stimuli and a subject's response can be useful indicators of the functional status of the photoreceptors and other visual processing stages in the retina. 3 Although accurate assessment of changes in chromatic sensitivity remains largely unexplored, other vision attributes such as hyperacuity, 4 contrast sensitivity, 5 dark adaptation, 6 and microperimetry 7 have been studied in AMD with some correlation between decreased retinal sensitivity and structural markers derived from spectral-domain optical coherence tomography (SD-OCT). 8,9 With improvements in infrared imaging, the interest in RPD has increased; these deposits are internal to the RPE and the presence of RPD is frequently associated with decrease in scotopic thresholds, suggesting rod dysfunction, 6 but the link to loss of color vision remains unexplored.…”

Developing prognostic biomarkers in intermediate age‐related macular degeneration: their clinical use in predicting progression

“…Ongoing efforts persist to identify clinically meaningful, reliable and appropriately sensitive, functional measures in early to intermediate AMD. More detailed reviews of visual function deficits in AMD are available elsewhere …”