Parkinson's disease and reading performance

Abstract

Purpose: Visual and reading difficulties affect 80% of individuals with Parkinson's disease (PD). Despite this, reading speed (RS) in PD has not been studied extensively. This investigation aimed to compare RS and reading acuity (RA) in participants with PD and in a control group (CG) using the Radner–Vissum reading charts. Methods: CG inclusion criteria included no visual/systemic or neurodegenerative diseases, no medications affecting vision, the ability to follow test instructions and providing informed consent. For PD participants, they were diagnosed by a neurologist, classified by the Hoehn and Yahr scale, received no vision therapy and had no dementia. Fifty-two participants were recruited in each group. The Radner–Vissum reading charts assessed RA and RS. Participants read sentences aloud with their optimal refractive correction. Analysed variables included: age, sex, RA, corrected RA score, maximum, mean and minimum RS (MAX-RS, MEAN-RS and MIN-RS), total words per minute (wpm) read, distance to near visual acuity ratio and critical print size (CPS). Results: PD participants exhibited reduced RS and RA, made more reading errors and had poorer RA scores than the CG (−0.05 vs. 0.08, p < 0.001). MAX-RS (201 vs. 191), MEAN-RS (162 vs. 148), MIN-RS (65 vs. 64) and total wpm (2023 vs. 1721, p = 0.003) were lower in PD participants. Higher CPS values and lower logMAR/logRAD (99.73% vs. 95%, p = 0.002) in PD participants indicated poorer reading performance (0.17 vs. 0.27, p < 0.001). No significant differences were found between PD participants at different Hoehn and Yahr stages, but a trend towards worsening was observed. Conclusions: Participants with PD experience significant reading problems compared with CG, underscoring the necessity for targeted interventions. These findings highlight the importance of assessing reading skills to understand the limitations that people with PD face daily. Future research should focus on identifying specific treatment strategies and exploring additional factors that may improve reading performance.