New computer-based test for red desaturation in optic neuropathy

The authors designed a simple, computer-based test for quantifying red desaturation severity in patients with optic neuropathy. 

Red desaturation is a subjective, sensitive test for patients with optic nerve disease. There is no quantitative clinical test to measure the severity of color desaturation. The current study introduces a simple test in the form of a PowerPoint presentation for quantification of red desaturation in patients with optic neuritis.

In the test, the patient holds a black cardboard divider between his or her eyes, such that each eye can see one-half of the screen. Each eye is shown a red square that changes in the degree of red desaturation in successive slides until the desaturation of the red square presented to the normal eye matches the color of the red square seen with the tested eye.

The authors administered the test to 42 normal volunteers and 41 patients with optic neuritis. Desaturation was graded by the number of slide changes needed until subjective equal color between the eyes is perceived.

Patients with optic neuritis had a significantly increased desaturation compared to controls (6.17 vs. 0.24, respectively; P < 0.0001).

The authors conclude that this test is easy to create and fills the need for a quickly administered, easily scored quantitative test for clinical use in acquired color vision deficiencies, such as optic neuritis.