Abstract
Purpose: :
To examine how reading speed and impairment are affected by glaucoma and visual field loss amongst participants of the Salisbury Eye Evaluation (SEE).
Methods: :
Reading speed was studied in the 1,250 participants of SEE. Non-scrolling newspaper-sized text was displayed on a screen and reading speed was defined by the rate at which words were correctly read aloud. A reading speed under 90 words/minute was defined as impairment. All patients were diagnosed as no, possible, probable or definite glaucoma by a specialist based on optic disc appearance and visual field testing using the SITA fast algorithm.
Results: :
The prevalence of probable or definite glaucoma was 11.8%, including 74 subjects (5.9%) with unilateral glaucoma, and 74 (5.9%) with bilateral glaucoma. Mean reading speed for all subjects was 137 words/min, with 17.8% of subjects reading impaired. Univariate analysis demonstrated lower reading speeds with bilateral glaucoma, increasing age, black race, lower MiniMental State Exam (MMSE) score, depression, worse presenting acuity, lower visual field mean deviation, and more visual field points in the central 20º of either eye with a sensitivity <24 dB. A multivariate linear regression model including age, race, MMSE score, and depression found no change in reading speed for subjects with unilateral glaucoma (-6.3 words/min, p=0.31, 95% CI=-18.5 to 5.8) or bilateral glaucoma (-7.4 words/min, p=0.27, 95% CI=-20.4 to 5.6). Multivariate models including age, race, MMSE score, depression, and presenting acuity showed decreased reading speed (-0.33 words/min/point, p=0.02) and more frequent reading impairment (OR 1.02/point, p=0.03) with increasing numbers of visual field points in the central 20º with a sensitivity <24 dB.
Conclusions: :
On average, persons with glaucoma in SEE had similar reading speeds to unaffected individuals. Central visual field loss affected reading speed, even after adjusting for visual acuity, suggesting that specific types of field loss may impact reading.
Keywords: reading • clinical (human) or epidemiologic studies: outcomes/complications • visual fields