Structural and Functional Characteristics of Color Vision Changes in Choroideremia

Abstract

Color vision is considered a marker of cone function and its assessment in patients with retinal pathology is complementary to the assessments of spatial vision [best-corrected visual acuity (BCVA)] and contrast detection (perimetry). Rod-cone and chorioretinal dystrophies—such as choroideremia—typically cause alterations to color vision, making its assessment a potential outcome measure in clinical trials. However, clinical evaluation of color vision may be compromised by pathological changes to spatial vision and the visual field. The low vision Cambridge Color Test (lvCCT) was developed specifically to address these latter issues. We used the trivector version of the lvCCT to quantify color discrimination in a cohort of 53 patients with choroideremia. This test enables rapid and precise characterization of color discrimination along protan, deutan, and tritan axes more reliably than the historically preferred test for clinical trials, namely the Farnsworth Munsell 100 Hue test. The lvCCT demonstrates that color vision defects—particularly along the tritan axis—are seen early in choroideremia, and that this occurs independent of changes in visual acuity, pattern electroretinography and ellipsoid zone area on optical coherence tomography (OCT). We argue that the selective loss of tritan color discrimination can be explained by our current understanding of the machinery of color vision and the pathophysiology of choroideremia.

A cross-sectional study to assess the clinical utility of modern visual function assessments in patients with inherited retinal disease: a mixed methods observational study protocol

“…Recent research has focused on improving visual function measures in patients with choroideremia and RPGR- associated RP, such as optimising microperimetry testing, visual field testing, VA testing strategies and understanding the clinical significance of low luminance VA [ 5 , 10 , 22 , 23 , 28 , 33 – 35 ]. Further research has focused on other measures of visual function in choroideremia, including colour vision and near vision reading acuity [ 36 , 37 ]. This project builds on this previous work, investigating outcome measures in a broader cohort of patients with inherited retinal disease.…”

Alterations of color vision and pupillary light responses in age-related macular degeneration

“…The CCT has been widely used for a wide range of health conditions; still, its limitation remains the same as for most color tests as it also relies on the VA for reliable results. Although some color vision tests are available for patients with lower vision, only few tests are suitable for patients with severely impaired visual acuity or visual field ( Jolly et al, 2021 ). Thus, we focused on early signs of color vision alterations in patients in the first stage of the disease.…”

Optimal Learning Samples for Two-Constant Kubelka-Munk Theory to Match the Color of Pre-colored Fiber Blends

“…In the textile industry, blending two or more pre-colored fibers to produce a variety of colors is an important coloring method, which has special color perception effects such as structural non-uniform or mottled appearance (Jolly et al, 2021). One of the most important tasks for the industry is to find the appropriate proportion of the pre-colored fibers to exactly match the color of a target sample required by the customer.…”