Preliminary Evaluation of Two Digital Image Processing Strategies for Head-Mounted Magnification for Low Vision
Ashley D Deemer1, Bonnielin K Swenor1, Kyoko Fujiwara1
1Lions Vision Research and Rehabilitation Center, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Translational Vision Science & Technology
|March 6, 2019
Summary
This study shows that a head-mounted display (HMD) with virtual magnification improves reading and visual information processing for people with low vision. However, it did not enhance mobility or visual motor function.
Area of Science:
- Ophthalmology
- Biomedical Engineering
- Human-Computer Interaction
Background:
- Low vision significantly impacts daily activities.
- Innovative magnification technologies are needed to improve visual function.
Purpose of the Study:
- To evaluate the effectiveness of a head-mounted display (HMD) system combining virtual bioptic telescope and projection screen for low vision patients.
- To assess the impact of this HMD system on self-reported visual function during everyday activities.
Main Methods:
- 30 participants with best-corrected visual acuity <20/100 and central scotomas were recruited.
- Participants underwent training and a 7- to 10-day in-home trial of the HMD system.
- Rasch analysis was used to evaluate changes in visual function using the Activity Inventory, SSQ, and system-use survey.
Main Results:
- Significant improvements were observed in reading (Cohen's d = 1.28) and visual information processing (d = 1.11).
- Functional ability measures showed significant gains (d = 0.79).
- No improvements were noted in visual motor function or mobility; one participant reported discomfort.
Conclusions:
- The HMD system effectively improved visual function in reading and information processing for individuals with low vision.
- Limitations in field of view and depth perception may explain the lack of improvement in mobility and visual motor function.
- The digital image processing and magnification approaches show promise for enhancing daily activities in low vision patients.
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