Mok Hao Ting, Yong Loo Lin School of Medicine, National University of Singapore
Given Singapore’s ageing population, falls amongst elderly patients have become common in today’s society. Dr Alex Black, Senior Lecturer in the School of Optometry and Vision Science at the Queensland University of Technology (QUT), Brisbane, Australia, was an invited overseas guest speaker at the Singapore Primary Eye Care Symposium (SPECS) 2019 held at One Farrer Hotel on 23-24 July 2019. His lecture titled ‘Prescribing for Falls Prevention in Older Adults’ emphasised the importance of vision in preventing falls and Dr Black shared various fall prevention strategies.
Falls among the elderly result in fear and activity restriction, loss of independence and institutionalisation. Almost 3% of all hospitalisations for patients aged over sixty-five are a result of falls, with an estimated health cost of 500 million a year attributed to falls in Australia. There are multiple fall risk factors and can be categorised into intrinsic and extrinsic factors. Intrinsic factors include age, gender, gait and balance, systemic conditions, multiple medications, fall history and vision impairment. Extrinsic factors consist of poor lighting, foot wear and trip hazards. Patients who identify with at least four risk factors have a 78% increase in their risk of falling.
Amongst these factors, vision and eye diseases play an intricate role in falls in older adults. Vision is the dominant balance sensory system of the body and patients with vision impairment are twice as likely to be involved in a fall. Good vision allows one to detect and avoid obstacles while walking, and aids in path planning and foot placement, reducing the probability of a fall. Common visual impairments in elderly patient include uncorrected refractive error, which can be prevented with optimum correction, and cataract, which can be removed by undergoing cataract surgery. Additionally, multifocal and progressive lens wearers are twice as likely to experience a fall compared to non-multifocal wearers, due to blur at the ground level increasing risk of trips and slips.
With good vision playing an integral role in reducing the risks of falls, there are multiple vision interventions that may prevent falls. A randomised trial was carried out involving 600 older adults, some of whom received eye care intervention involving comprehensive eye examinations, while the control group carried on with their daily activities as per usual. Through this trial, it was derived that an updated prescription provides improved clarity but could also increase fall risks, especially in those with large changes in prescription. For example, participants who received small changes in prescription were less likely to fall as compared to those receiving large prescription changes. Sudden large changes in prescription and associated magnification may alter the vestibulo-ocular reflex, causing dizziness and discomfort, exacerbating fall risks. Eye care professionals should apply changes in magnification and astigmatism gradually, to mitigate this problem.
Studies have also proven that elderly patients who undergo cataract surgery are less likely to fall. Post-operatively, eye care professionals should allow patients to have a period of adaptation, and avoid making large refractive errors as this may increase the risk of falls. It is also advisable to avoid prescribing bifocal or progressive lens to active elderly patients, with recommendations to promote the use of single vision distance glasses for their outdoor activities. Additionally, if a patient intends to wear distance glasses after cataract surgery, new lenses should be provided in between the first and second surgery.
Dr Black highlighted the importance of regular eye examinations, to allow for small changes in refraction and avoid large changes. Eye care professionals should also encourage elderly patients to undergo cataract surgery, as this promotes improved mobility and independence, and reduces the chance of falling. Moreover, fall risk patients who are active are recommended to wear their distance glasses outdoors and multifocal lens at home or indoors. Patients with visual impairment should also seek home modifications, by removing trip hazards. Eye care professionals have an important role to play in early detection of eye disease and subsequent reduction in the risk of falls in the elderly.