Quantifying Color Vision Changes Associated With Cataracts Using Cone Contrast Thresholds

Abstract

Purpose: To evaluate effects of age and simulated and real cataractous changes on color vision as measured by the high-definition cone contrast test (CCT).

Methods: Twenty-four healthy volunteers from two cohort studies performed CCT using best-corrected visual acuity, filters, mydriasis, and pinhole correction. Retrospective cross-sectional study of patients seen in eye clinics evaluated the relationship between age and color vision, and age and lens status in 355 eyes. Last, 25 subjects underwent CCT before and after cataract surgery.

Results: CCT scores were most reliable in the nonmydriatic condition without pinhole correction. Progressively dense brown filters produced small decreases in S-cone sensitivity. Linear regression analysis of phakic subjects showed a decline for all cone classes with age. Rate of decline was greater for S-cones (slope = -1.09; 95% confidence interval [CI], -1.30 to 0.86) than M-cones (slope = -0.80; 95% CI, -1.03 to -0.58) and L-cones (slope = -0.66; 95% CI, -0.88 to -0.44). CCT scores increased for S-cones but reduced for L- and M-cones in pseudophakic subjects compared with phakic patients. CCT scores after cataract surgery increased for S-cones, M-cones, and L-cones by 33.0 (95% CI, 8.6 to 57.4), 24.9 (95% CI, 3.8 to 46.0), and 22.0 (95% CI, -3.2 to 47.3), respectively.

Conclusions: CCT assessment allows for clinically practical quantitation of color and contrast vision improvement after cataract surgery and aging patients who note poor vision despite good visual acuity.

Translational relevance: CCT testing, which quantifies hereditary and acquired color deficiency, can also quantify the degree of cataract severity and, combined with other parameters, can provide more precise guidance for cataract extraction to optimize patient care.

Keywords: age-related decline in color vision; color vision changes associated with aging; color vision changes before and after cataract surgery; cone contrast test; cone contrast threshold.

Figure 1.

(a) Spectral transmission of NDs. (b) Effect of testing conditions on CCT scores. This was estimated via linear regression with generalized estimating equations to account for repeated measurements (n = 18). Error bars represent 95% CI with Bonferroni correction (α = 0.05/18 = 0.0028) and correspond to 2.77 times the standard error of the mean CCT score for each group. *Statistically significant differences from baseline. LogCS scores are included above each bar of Figure 1b.

Figure 2.

(a) Configuration for measuring cone contrast sensitivity from the ColorDx monitor, with (b) spectral emission of the CCT monitor, (c) spectral transmission of brown filters, and (d) effect of simulated cataractous changes on CCT scores. Error bars represent 95% CI with Bonferroni correction (α = 0.05/18 = 0.0028) and correspond to 2.77 time the standard error of the mean CCT scores for each group. *Statistically significant differences from baseline (n = 6). LogCS scores are included above each bar of Figure 2d.

Figure 3.

Effect of Age on Color Vision in (a) phakic eyes from 6 years to 90 years old (n = 256 eyes) (b) pseudophakic (n = 57) eyes vs phakic eyes (n = 42) in patients older than 50 years of age.

Figure 4.

Changes in color vision before and after cataract surgery (n = 25). Error bars represent 95% CI with Bonferroni correction (α = 0.05/18 = 0.0028) and correspond to 2.77 times the standard error of the mean CCT score. *Mean changes significant. LogCS scores are included above each bar of Figure 4.