The size of the visual span was the only significant contributor to reading speed in glaucoma when binocular visual acuity, binocular contrast sensitivity, stereoacuity and visual field in the better eye were held constant, according to researchers.
Researchers examined the factors that may underlie slow reading in glaucoma and determined the best predictor of reading speed.
A total of 38 subjects took part, 17 with primary open-angle glaucoma and 21 age-similar normal controls.
Researchers measured binocular visual acuity (BVA), binocular contrast sensitivity (BCS), stereoacuity, visual field mean deviation and the visual span known to limit reading speed.
The glaucoma patients showed significantly slower reading speed and smaller visual span compared to normal controls, even after controlling for age.
While patients with glaucoma had relatively normal BVA, their BCS, stereoacuity and visual field mean deviation showed pronounced deficits, according to researchers.
The researchers concluded that reading speed in glaucoma was best predicted by the visual span.
This study further supports the view that reading difficulties are present even in relatively moderate stages of glaucoma and associated with noticeable defects in stereoacuity and BCS.
Even in early or moderate stages of glaucoma, stereopsis, convergence and binocular fusion are significantly more impaired in those with glaucoma, compared to glaucoma suspects or normal cohorts, they wrote. – by Abigail Sutton
Disclosures: The researchers report no relevant financial disclosures.