[Comparison between binocular and monocular reading ability and its relation with central visual field sensitivity in...

To evaluate binocular and monocular reading ability in glaucoma patients with good visual acuity and to examine its relationship with central visual field sensitivity.

Glaucoma patients(35 individuals, mean +/- SD : 51.8 +/- 12.9 years) with a decimal visual acuity in each eye of >or=1.0, reading ability was tested both binocular and monocular using Japanese version of Minnesota Reading Acuity Chart (MNREAD-J). Reading ability parameters were calculated for maximum reading speed (MRS), critical print size (CPS), and reading acuity (RA). The results were compared with those of people with normal vision; differences in reading ability under varied testing conditions and correlations between visual field sensitivity and each parameter were examined.

Under binocular reading conditions, MRS, CPS, and RA were decreased significantly in glaucoma patients compared with normal controls (p = 0.00044, p = 0.00004, p = 0.00028, respectively). Under monocular reading conditions, glaucoma patient MRS and RA were decreased significantly in comparison with normal controls (p=0.00155, p= 0.00142). In glaucoma patients undergoing binocular reading tests, MRS was greatest in the paracentral bottom right quadrant of the worse eye (r = 0.41709, p= 0.04447). The CPS decreased in proportion to the extent of the difference between both eyes in the mean deviation value and the visual field sensitivity of the paracentral bottom left (r = 0.40693, p = 0.02699 and r=0.41478, p=0.02384). RA improved in proportion to the extent of the difference between both eyes in the visual field sensitivity of the upper left (r = 0.33557, p=0.04799).

In glaucoma patients, binocular reading is not necessarily useful in cases of visual field sensitivity differences.