Reading ability and reading engagement in older adults with glaucoma

Abstract

Purpose: We evaluated the impact of glaucoma-related vision loss on reading ability and reading engagement in 10 reading activities.

Methods: A total of 63 glaucoma patients and 59 glaucoma suspect controls self-rated their level of reading difficulty for 10 reading items, and responses were analyzed using Rasch analysis to determine reading ability. Reading engagement was assessed by asking subjects to report the number of days per week they engaged in each reading activity. Reading restriction was determined as a decrement in engagement.

Results: Glaucoma subjects more often described greater reading difficulty than controls for all tasks except puzzles (P < 0.05). The most difficult reading tasks involved puzzles, books, and finances, while the least difficult reading tasks involved notes, bills, and mail. In multivariable weighted least squares regression models of Rasch-estimated person measures of reading ability, less reading ability was found for glaucoma patients compared to controls (β = -1.60 logits, P < 0.001). Among glaucoma patients, less reading ability was associated with more severe visual field (VF) loss (β = -0.68 logits per 5-dB decrement in better-eye VF mean deviation [MD], P < 0.001) and contrast sensitivity (β = -0.76 logits per 0.1-unit lower log CS, P < 0.001). Each 5-dB decrement in the better-eye VF MD was associated with book reading on 18% fewer days (P = 0.003) and newspaper reading on 10% fewer days (P = 0.008). No statistically significant reading restriction was observed for other reading activities (P > 0.05).

Conclusions: Glaucoma patients have less reading ability and engage less in a variety of different reading activities, particularly those requiring sustained reading. Future work should evaluate the mechanisms underlying reading disability in glaucoma to determine how patients can maintain reading ability and engagement.

Keywords: glaucoma; low vision; quality of life; reading.

Figure 1

Percentage of glaucoma and control subjects reporting difficulty for each of 10 different reading tasks. Responses were partitioned into three categories of difficulty: no difficulty (not shown), mild difficulty, and moderate-to-severe difficulty.

Figure 2

Distribution of reading ability from Rasch-estimated item measure and person measure scores (logits) mapped onto the same scale. Higher person measure scores indicate less reading ability in the individual. Higher item measure scores indicate less difficulty associated with the particular task. Item measure scores are found at the midpoint of the transition point from no difficulty to severe difficulty.

Figure 3

Box-whiskers plots of Rasch-estimated person measure score (logits) of control and glaucoma subjects, showing the 25th and 75th percentile range (box) and median values (transverse lines in the box).

Figure 4

Task-specific rate ratios of reading engagement for each 5-dB decrement in the better-eye VF MD with horizontal lines indicating 95% CI. Statistically significant reading restriction was noted for books and newspapers (P < 0.05).