The Light and the Dark of Early and Intermediate AMD: Cone- and Rod-Mediated Changes Are Linked to Fundus Photograph and FAF Abnormalities

Abstract

The light and the dark of early and intermediate AMD: cone-and rodmediated changes are linked to fundus photograph and FAF abnormalities.

Are Current Methods of Measuring Dark Adaptation Effective in Detecting the Onset and Progression of Age-Related Macular Degeneration? A Systematic Literature Review

“…Dimitrov et al [15,41] assessed using both techniques. Eight studies used an adapted Humphrey Visual Field Perimeter (HVFP; Carl Zeiss Meditec, Inc, Dublin, CA, USA) [43][44][45][46][47][48][49][50] and eight utilised an 'in-house' adaptometer, with methods developed by investigators [15,41,42,[61][62][63][64][65]. Other adaptometers, featured in more than one study, included the Medmont Dark Adapted Chromatic perimeter (MDAC; Medmont Pty Ltd, Melbourne, Australia) (5 out of 27 studies) [55][56][57][58][59] and the Macular Disease Detection MDD-2 Ò device (Health Research Science, LLC, Lighthouse Pt, FL, USA) (2 out of 27 studies) [53,54].…”

“…The most frequently reported parameters of DA in studies that did not use the AdaptDx were RCB (10 out of 27 studies) [41, 42, 44-48, 60, 63, 65], cone absolute threshold (9 out of 27 studies) [41, 42, 44-48, 63, 65], cone time constant (8 out of 27 studies) [44][45][46][47][48][49][50]65] and RIT/ rod criterion time (7 out of 27 studies) [41,[55][56][57][58][59]63]. Other parameters in the reviewed papers included rod absolute threshold (5 out of 27 studies) [41,[46][47][48]63] and 'second slope' or rod slope (5 out of 27 studies) [42,[46][47][48]65], which refers to the second phase of rod recovery when threshold data are fitted with a model based on the physiological process of DA [7].…”

“…To examine cone-mediated DA, frequently reported stimulus wavelengths of * 620 nm [55,56] or 650 nm [47,48] were seen in the literature. Eight studies used a threshold location of 12°eccentricity [46][47][48][55][56][57][58][59], seven studies used a 5.5-6°l ocation [42,[55][56][57][58][59]65], seven studies used an 3.5-4°location [15,41,[55][56][57][58][59], six studies used a foveal location [41,44,45,49,50,63], five studies used an 8°location [55][56][57][58][59] and two studies used a 3°location [42,65].…”

“…No cut-off times signifying the end of the DA assessment were reported for the photostress tests, as the nature of the examination is for the patient to return to baseline sensitivity, which occurs relatively quickly [43,52,64]. The most often reported cut-off time for the DA procedure was 30 min (7 out of 27 studies) [15,41,45,55,57,59,63], followed by 60 min (3 out of 27 studies) [47,48,65]. Four of these studies reported that the recovery parameter was set to the maximum test time as a censored data point [44,45,58,59,65], similar to the procedure followed by studies that used the AdaptDx.…”

“…Furthermore, Rodrigo-Diaz et al [65] found that parameters of the DA curves such as the rod-mediated second slope and the RCB were associated with FAF changes and CFP grading. However, only a moderate correlation at best was found between cone time constant and measures from FAF and CFP grading [65].…”