Color visual acuity in preperimetric glaucoma and open-angle glaucoma

Purpose To investigate the clinical significance of color visual acuity (CVA) in preperimetric glaucoma (PPG) and open-angle glaucoma (OAG). Methods A total of 123 eyes of 73 subjects (22 normal eyes, 14 PPG eyes, and 87 OAG eyes; mean age: 44.9 +/- 10.1 years, age range: 21-64 years) were enrolled. CVA was tested for red, green-yellow, blue-green and blue-purple with a newly developed test. Results There was no statistical difference in clinical background factors, including age, sex, intraocular pressure, or spherical equivalent between the three groups. Red VA and blue-green VA were significantly worse in the OAG eyes than in the normal eyes (P= 0.008 and P= 0.015, respectively), although green-yellow VA and blue-purple VA were not significantly worse. Furthermore, red VA and blue-green VA were significantly correlated with MD in a group of eyes with either PPG or OAG (r=-0.23, P= 0.023; r=-0.25, P= 0.012, respectively), but green-yellow VA and blue-purple VA were not. Conclusion Red VA and blue-green VA were detectably worse in eyes with OAG, in close association with the degree of functional loss. This suggests that measuring CVA with the new color test described here may be a promising supplement to existing methods of detecting glaucoma and evaluating its severity.