As proven in studies dating back to the eighteenth century, color vision changes may occur early in the course of glaucoma. Our aim was to reevaluate the incidence of acquired color vision deficiency in glaucoma patients of the University hospital Zürich by using the Panel D-15 test.
Inclusion criteria of the study involved a diagnosis of glaucoma, age equal or greater than 18 years with no upper limit and a best-corrected visual acuity (BCVA) smaller than ≤ 0.7 logMAR. All volunteers were tested twice monocularly for color vision with (1) the Ishihara color plate test and (2) the Farnsworth and Lanthony Panel D-15 test by one examiner (L.B.). Using the Moment of Inertia Method of Vingrys and King-Smith (Investig Ophthalmol Vis Sci 29(1):50-63, 1988), we measured the color defect type (blue-yellow, red-green or non-selective).
One hundred and fifty-one eyes of 87 glaucoma patients were included in this study. Nine eyes showed a deficient result in the Ishihara test, which proves a congenital red-green weakness. Fifty-one (33.8%) eyes showed color vision anomalies in the desaturated test and 24 (15.9%) eyes in the saturated Panel D-15 test. A total of 25.2% and 8.6% of eyes in the desaturated and saturated test were diffuse dyschromatopsia, respectively. The second most prevalent deficiencies were blue-yellow defects with 4.0% and 4.6% of saturated and desaturated results. Just the covariate visual acuity had a significant influence on the Panel D-15 result, whereas other variables like age, sex or intraocular pressure did not show any impact.
This study ascertains that the long-known theory of color vision defects in patients with glaucoma is also relevant in our sample of 151 eyes, providing continuity to claims firstly reported many years ago. Despite our results highlighting more diffuse dyschromatopsia than other similar experiments, we have also proven that the tritanomalous defects occur more frequently than other color defects.