Enhanced text spacing improves reading performance in individuals with macular disease

Area of Science:

• Ophthalmology
• Visual Science
• Human Factors

Background:

• Reading difficulties are common in individuals with no central vision, such as those with age-related macular degeneration (ARMD).
• Previous attempts to improve reading speed through textual modifications have yielded limited success.
• Visual crowding, the difficulty in identifying targets viewed eccentrically due to adjacent stimuli, is a suspected major contributor to inefficient reading.

Purpose of the Study:

• To investigate the impact of combined line and word spacing on reading performance in individuals with ARMD.
• To evaluate the effectiveness of different text spacings with both high and low letter contrast.

Main Methods:

• Participants with ARMD read short text passages under varying conditions of line and word spacing.
• Text was presented in both high (87.5%) and low (17.5%) contrast.
• Reading speed and error rates were measured and compared across different spacing conditions.

Main Results:

• Double line and double word spacing resulted in the fastest reading speeds for both high and low contrast text.
• Compared to single spacing, double spacing increased reading speed by 26% (high contrast) and 46% (low contrast).
• Double spacing more than halved the number of reading errors compared to single spacing.

Conclusions:

• Visual crowding negatively impacts reading in individuals with ARMD.
• Enhanced text spacing, particularly double line and word spacing, effectively reduces the negative effects of crowding.
• Increased spacing is crucial for improving reading efficiency, especially when text contrast is reduced due to factors like intraocular light scatter.