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Intermediate addition multifocals provide safe stair ambulation with adequate 'short-term' reading
David B Elliott1, John Hotchkiss1, Andrew J Scally2
1Bradford School of Optometry and Vision Science, University of Bradford, Bradford, UK.
Summary
Intermediate addition multifocal lenses offer similar stair safety to single-vision glasses for older adults. These multifocals improve near vision and may increase adherence for fall prevention strategies.
Area of Science:
- Ophthalmology and Vision Science
- Gerontology
- Biomechanics
Background:
- Previous research showed distance single-vision spectacles reduced falls risk in older adults but had poor adherence due to switching glasses.
- Older adults often wear multifocal lenses for near and distance vision correction.
Purpose of the Study:
- To evaluate if intermediate addition multifocal lenses provide comparable gait safety on stairs to distance single-vision spectacles.
- To assess if intermediate addition multifocal lenses offer adequate short-term reading and near vision.
- To determine if intermediate addition multifocal lenses improve adherence compared to switching glasses.
Main Methods:
- Fourteen healthy long-term multifocal wearers performed stair ascent/descent trials with various lenses: intermediate and full addition bifocals, progression-addition lenses (PALs), and single-vision distance spectacles.
- Gait safety was measured using foot clearance (toe on ascent, heel on descent) and trial duration.
- Near visual acuity, critical print size, and reading speed were assessed using standard charts at 40 cm.
Main Results:
- Gait safety measures were poorer with full addition bifocals and PALs compared to intermediate addition bifocals and PALs.
- Intermediate addition PALs demonstrated similar stair ascent/descent gait parameters to distance single-vision spectacles.
- Intermediate addition PALs provided superior near word acuity and critical print size compared to single-vision lenses, suitable for short-term tasks.
Conclusions:
- Intermediate addition PALs offer a viable alternative to distance single-vision spectacles for improving stair gait safety in older adults.
- The improved 'spot reading' ability with intermediate addition PALs may enhance adherence for outdoor use in elderly individuals.
- Further randomized controlled trials are recommended to confirm the effectiveness of intermediate multifocals in fall prevention.
