Comparison of Results between Hahn Test and D-15 Test in Patients with Optic Neuritis

Purpose: The results of the Hahn Chun Suk color test (Hahn test) and the Farnsworth-Munsell D-15 test (D-15 test) were compared in patients with acute optic neuritis.Methods: Patients with acute optic neuritis evaluated using both the Hahn and D-15 tests in the acute phase and 2 months later were evaluated. The results of the acute phase tests were compared. Correlations were sought between color deficiency and all of visual acuity, the visual field index (VFI), and the severity of optic disc edema. Changes in the test results 2 months later were also evaluated and correlated with other visual functions.Results: Twenty-seven eyes of 22 patients were enrolled. The mean patient age was 49.4 years and the logarithm of the minimum angle of resolution visual acuity 0.5. In the acute phase, the perception number was 10.06 in the Hahn test. On the D-15 test, the ‘strong’ grade predominated (40.7%). The concordance rates of severity and type were 55.6 and 54.5% between the two tests. In 9 of 12 eyes exhibiting inconsistent severity, the D-15 test afforded better results than did the Hahn test. A significant positive correlation was evident between the Hahn test results and visual acuity (r = 0.560, p = 0.002). The mean deviation (MD) and the VFI also correlated with the results of the Hahn test (r = -0.432, p = 0.027 for the MD; r = -0.517, p = 0.007 for the VFI). The D-15 test results correlated only with visual acuity (r = 0.476, p = 0.012). After 2 months, the results of both tests correlated significantly only with visual acuity.Conclusions: In the acute phase, the concordances of the Hahn and D-15 test results were 55.6% in terms of severity and 54.5% in terms of type. The Hahn test results correlated with the visual acuity and VFI. In contrast, the D-15 test results correlated with visual acuity only.