Abstract
Purpose :
Acquired color and visual field defects are associated with ocular and systemic disorders like diabetes. Traditional perimetry can fail to detect subtle changes in retinal health, leading to interest in the clinical applications of chromatic perimetry. Our group previously reported interocular repeatability of a novel color perimeter. Here we expand on that work to establish its repeatability at four different regions of the same eye in a cohort of healthy subjects over time.
Methods :
Seven subjects (39.57±6.88 years) participated with 2 visits 5 months apart. Functional tests performed were visual acuity, Mars Letter Contrast Sensitivity, L’Anthony Desaturated D-15 and color perimetry. HbA1c was completed to rule out diabetes. The color perimetry measurements were taken at four points all 3° from fixation in the right eye: inferior nasal, inferior temporal, superior temporal, and superior nasal with a stimulus size of 0.5° in diameter. Chromatic sensitivity thresholds were obtained through a staircase method that produced a single threshold value for each location for red, green, blue, and yellow. These thresholds were converted to cone contrast. Test-retest repeatability was measured with Pearson correlation coefficient and Bland-Altman analysis.
Results :
There was no difference in clinical functional testing between visits. The HbA1C (5.40 ± 0.38; p= 0.29); Mars Letter contrast sensitivity (1.77 ± 0.04; p=0.20) and color confusion index (1.033 ± 0.088; p=0.77). The overall threshold values on the color perimetry were 0.033 red, 0.038 green, 0.134 blue, and 0.157 yellow across locations and did not change between visits (all p >0.2). The perimetry had a strong correlation between visits, 0.88 across all points and colors, indicating clinical levels of test-retest repeatability. The positions were also highly correlated (0.92 superior temporal, 0.96 superior nasal, 0.86 inferior nasal and 0.87 inferior temporal). When examining data by color, they ranged in correlation with green (0.72) and red (0.61) having better repeatability over time than blue (0.44) and yellow (0.45).
Conclusions :
Color perimetry has excellent test-retest repeatability over several months in healthy participants. Red and green are especially robust while yellow and blue have more variability. A larger sample is needed, but this provides a good foundation for testing those with diabetes and glucose dysfunction in future work.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.