Practice Effects and the Lanthony D15

Area of Science:

• Ophthalmology
• Optometry
• Genetics

Background:

• Congenital colour vision deficiency (CVD) affects an individual's ability to perceive colours accurately.
• The Farnsworth D15 (FD15) test, using saturated colours, has shown that practice can improve performance in individuals with CVD.
• The Lanthony D15 (LD15) test utilizes desaturated colours, presenting a greater challenge, even for those with mild CVD.

Purpose of the Study:

• To investigate whether intentional practice can enhance the performance of individuals with congenital CVD on the Lanthony D15 (LD15) test.
• To determine if subjects with congenital colour vision deficiency can improve their scores on a more challenging colour vision test through deliberate practice.

Main Methods:

• Twenty-one male subjects with congenital CVD underwent a two-visit study.
• Colour vision status was confirmed using standard tests (colour vision book, anomaloscope, FD15).
• Subjects completed four LD15 trials at baseline and four after a practice period, with performance measured by colour confusion indices (CCI).

Main Results:

• A statistically significant reduction in CCI was observed between the baseline and practice visits (p=0.01).
• Subjects with deutan deficiency demonstrated significant improvement (p=0.003), while protan deficiency subjects showed no significant change (p=0.88).

Conclusions:

• Congenital red-green CVD subjects can improve their performance on the Lanthony D15 test through practice.
• The clinical significance of this improvement on pass-fail rates, especially with high baseline CCIs, requires further investigation.