Abstract
Purpose :
The Goldmann-Weekers Dark Adaptometer (GWDA), the historic "gold standard" for clinical measurement of dark adaptation, has been out of production for decades, and few working instruments remain available for clinical use. We compared a new alternative, the Dark Adaptation module for the Espion3/Colordome with the GWDA.
Methods :
Adapting lights were measured with an IL 1700 photometer. Adaptation curves of normal volunteers were obtained on the GWDA after a 5-minute bleach, and using various protocols for the Espion3/Colordome as provided by the manufacturer. Subjects gave informed consent under approval from the NYU Langone IRB.
Results :
The adapting luminance of the GWDA was 1019 cd/m2; the adapting luminance of the Espion3/ColorDome was 542 cd/m2 for a nominal luminance setting of 500 cd/m2.
GWDA adaptation curves featured an initial threshold near 0 dB, a cone-mediated adaptation phase with 2 log units of adaptation over 5-10 minutes, followed by a cone-rod break and second, rod-mediated adaptation phase showing an additional 2 log units of adaptation of the next 10 minutes.
The original Espion3/ColorDome protocol showed an initial threshold of -2.- to -3.0 dB, followed by an adaptation of less than 0.6 dB over the next 5-10 minutes, followed by a rod-cone break and a subsequent rod-mediated adaptation of 2 log units over the next 10 minutes. Subsequent protocols, including a masking attachment for the ColorDome and flickering test lights in lieu of simple brief flashes produced adapdtation curves very similar to those from the GWDA, but with initial thressholds between -2 and -3 dB.
An option on the Espion3/ColorDome to test adaptation with alternating red and green test lights worked well, showing a cone adaptation curve (response to red lights) matching the cone limb of the white light curve, but with no later rod limb, and a curve in response to green test lights which closely tracked the white light adaptation curve.
Conclusions :
The Epions3/ColorDome is a satisfactory alternative to the GWDA. Adaptation curves are similar, though the initial threshold displaced downward by 2 to 3 dB. The red-green test light paradigm clearly distinguishes between cone and rod adaptation processes.
This is a 2020 ARVO Annual Meeting abstract.