Colour Vision Deficits in Children with Amblyopia: Impact of Angular Size of Stimuli on Detection

Abstract

This study investigates colour vision deficits in children with amblyopia by employing a computerized colour vision test with varying stimulus sizes (1°, 2°, and 3°). The aim is to delineate the impact of amblyopia on colour discrimination in children and to determine the effectiveness of the computerized colour vision test in detecting these deficits. The study involved 40 participants, divided into 20 children with amblyopia and 20 without amblyopia (control group). Our findings reveal that, during binocular viewing, children with amblyopia exhibit significant impairments in colour vision both for red-green and blue-yellow axes, primarily for 1° chromatic stimuli, but not for larger stimuli (2° and 3°). These findings offer valuable insight into the functional visual limitations in pediatric amblyopia, potentially guiding more targeted clinical assessments and interventions.

Keywords: amblyopia; children; colour vision; computerized colour vision test; stimulus size; visual deficits.

Figure 1

A diagram showing a brief description of the experiment.

Figure 2

The targets for the computerized colour vision test stimuli were as follows: (A) a chromatic target of 1 degree along the protanopia confusion lines, (B) a chromatic target of 2 degrees along the tritanopia confusion lines, and (C) a chromatic target of 3 degrees along the deuteranopia confusion lines.

Figure 3

The chromatic distances along the protanopia confusion lines varied depending on the angular size of the target stimulus across the entire control group.

Figure 4

The chromatic distances along the deuteranopia confusion lines varied depending on the angular size of the target stimulus across the entire control group.

Figure 5

The chromatic distances along the tritanopia confusion lines varied depending on the angular size of the target stimulus across the entire control group.

Figure 6

The CIExy diagram illustrates the colour direction codes along the protan, deutan, and tritan confusion lines, specifically PR-protan-red, PG-protan-green, DG-deutan-green, DR-deutan-red, TB-tritan-blue, and TY-tritan-yellow. The monitor’s white point, represented as a black point in the diagram, is chosen at coordinates (0.3188, 0.36). The confusion lines were selected to include the corresponding confusion points: protan (0.75, 0.25), deutan (1.4, −0.4), tritan (0, 0.17), and the monitor’s white point [45].

Figure 7

The chromatic distances along the protanopia confusion lines varied depending on the angular size of the target stimulus across the entire amblyopic group.

Figure 8

The chromatic distances along the deuteranopia confusion lines varied depending on the angular size of the target stimulus across the entire amblyopic group.

Figure 9

The chromatic distances along the tritanopia confusion lines varied depending on the angular size of the target stimulus across the entire amblyopic group.

Figure 10

The mean chromatic distance, depending on target angular size and visual acuity (in decimal units).