Aging—Preparing for the 21st Century

How will optometry practice change during the 21st century? No doubt, this will be influenced by many elusive factors, such as the emergence of new diagnostic and treatment modalities, changes in relevant health legislation, and economic developments. One vital factor that is very easy to anticipate is the changing demography of the people who require optometric services. In advancing their premise that demographics can be used to predict future directions in society, Foot and Stoffman suggested that “demographics explains two thirds or everything. 1 The remaining one-third may be the decisive factor in shaping events because counting bodies will never predict the arrival of a wonder drug, electoral outcomes or the emergence of gifted leaders.” Discussion of demographics at the present time is dominated by the aging of the population. According to the U.S. Census Bureau’s “middle series” projections, the elderly population (those aged over 65 years) will more than double between now and the year 2050, to 80 million. By that year, as many as 1 in 5 Americans could be elderly. Most of this growth should occur between 2010 and 2030, when the “baby boom” generation enters their elderly years. The “oldest old,” those aged 85 and over, is the most rapidly growing elderly age group. It is expected the oldest old will number 19 million in 2050. That would make them 24% of elderly Americans and 5% of all Americans. What is not as widely appreciated is the fact that population aging has occurred and is occurring in less industrialized countries as well. Uruguay, for example, currently has a higher percentage of older (60+) population than does Canada and the United States. Outside of Europe and North America, the Caribbean is the “oldest” region of the world, with 10% of its aggregate population aged 60 years and over. Optometric Practice Issues These demographic changes will have a significant impact on optometric practice. Indeed, some practitioners have seen an increase in the number of seniors reporting for optometric examination during the early 1990s 2 and this will continue to increase, particularly between 2010 and 2030. A practical first point is that offices/practices should be appropriately designed for the elderly. In this respect, in addition to considering the reduced vision of some older patients, it is important to remember that these patients may also have functional problems with mobility, hearing, and agility among other issues. A future major issue is likely to be the mushrooming of the low vision population and how these people can be adequately cared for. 3 Assuming that no miracle cures are imminent for any of the conditions that cause low vision, the most powerful intervention to assist people with low vision is proficient vision rehabilitation. Even to meet the needs of the current population, the optometric profession needs to increase its capacity to provide primary low vision care. 3 Several studies confirm that more than 75% of all low vision patients can benefit significantly when they are assessed with a modest selection of basic low vision aids. 4,5 The optometric profession will also need to increase it’s outreach services, as many seniors with low vision live in sheltered retirement or nursing homes. Key Research Areas Research into vision and aging is vital for several reasons: • We do not fully understand how and why even the most common age-related changes, such as presbyopia, occur. • We do not fully understand how and why vision deteriorates in people with healthy eyes. In addition, our understanding of human vision is based largely on the study of university-age subjects and it is not clear how relevant the conclusions reached are to the elderly person’s vision. • Several age-related conditions are as yet untreatable and cause considerable reductions in quality of life. • Although it is well-known how various age-related diseases affect visual function, we still have much to learn about the impact of visual impairment on disability and quality of life. 6,7 Similarly, ophthalmic intervention and rehabilitation should be more directed toward improving functional vision and quality of life rather than Snellen visual acuity. Presbyopia The burgeoning presbyopic patient population represents a huge market for practitioners prescribing spectacle lenses and/or contact lenses or for surgeons offering anterior segment surgeries. Just a few of the more widely accepted nonsurgical options available for treating presbyopes include bifocal or multifocal spectacle lenses, and monovision or multifocal contact lenses. There are still many questions regarding performance, tolerance, and comfort for elderly, first-time contact lens wearers. Current and future research efforts will provide answers to these questions. 8 Surgical options include monovision or multifocal corneal refractive surgical procedures, and for cataract patients monovision or multifocal intraocular lenses (IOLs). Several controversial and unproven scleral expansion surgical procedures, accomplished with PMMA segments inserted in the sclera or through radial slits in the sclera (anterior ciliary sclerotomy or ACS) are claimed to restore accommodation. These procedures are based on a revisionist theory of accommodation and presbyopia 9,10 that has been refuted 11,12 and for which no independent supporting studies exist. Furthermore, zero postoperative accommodation has been reported using independent, objective assessments. 13 Less controversial, although equally poorly understood, is the efficacy of artificial accommodative IOLs. Numerous patents exist for such devices. Research is underway to understand the efficacy of these devices and how they might be improved. 14 Some of the accommodative IOLs are undergoing clinical trials inside and outside of the United States. It is toward these developing surgical procedures that research effort is and will be directed. Although this research effort may establish if accommodation can be restored, there is much that remains unclear about the accommodative mechanism, aging of the accommodative apparatus, and the development of presbyopia. Research directed at understanding how the lens ages 15,16 and at the accommodative apparatus 17 continues to provide new insights, but there is much still to be learned. This research may help to understand how best accommodation may be restored, but it may also provide new information on how and why presbyopia develops. Although it is unlikely that presbyopia can be prevented from occurring, certainly a better understanding of why it occurs could provide important information as to how best to relieve presbyopia. Aging Changes in Normal, Healthy Eyes It is well-known that even in eyes free of eye disease, there is a reduction in many aspects of visual function with age. 18 These changes may have a significant impact on daily visual activities such as reading. 19 It is thought that the majority of these reductions are due to changes in the neural system rather than the optical system. 20 Reductions in vision due to reduced retinal illuminance caused by age-related miosis appear to be offset by the reduction in aberrations caused by the smaller pupil. 21 Because of the amount that is known about the visual system and the underlying neural mechanisms, plus the fact that visual stimuli can be produced with great precision and the responses recorded quantitatively and accurately, visual system aging has been proposed as an excellent model of aging for the neural system as a whole. 20 Age-Related Diseases The majority of low vision patients have age-related macular degeneration (AMD). Indeed, 75% of visually impaired seniors have AMD. Given the tremendous growth that is forecast to occur in the elderly population, the only development that could curb a correspondingly meteoric increase in the size of the low vision population is a safe and efficacious treatment for dry AMD. Many different treatment modalities are being researched, including laser and radiation therapies, retinal transplants, gene therapies, ozone and hyperbaric therapies, antioxidant and zinc therapies, thalidomide therapy, strontium 90 therapy, photochemical therapy, and microcurrent stimulation therapy. 22,23 No breakthrough developments have been reported to date, but fundamental and clinical research in this area should be strongly supported. A related area of study is whether cataract surgery could improve the vision of patients with both cataract and co-morbid eye disease, particularly AMD. There is growing evidence that some patients with both cataract and AMD benefit considerably from cataract surgery, 24 although other evidence suggests that cataract surgery may lead to the development of exudative macular degeneration in some patients with preoperative macular changes. 25 Quality of Life Issues Vision plays an important role in most everyday activities, so that elderly people with visual impairment are daily faced with problems such as recognizing objects and people, preparing meals, getting around (mobility), driving, reading, managing finances, socializing, and working. 26,27 These visual disabilities can lead to serious reductions in quality of life, including depression and social isolation. Research is required to provide an understanding of how different types of visual impairment affect functional vision and quality of life. 28 An important example is the lack of knowledge of the visual requirements for driving 29 and this is particularly pertinent given the importance of driving to independence in the U.S. Research is also required to determine whether these reductions in functional vision and quality of life could be improved with ophthalmic intervention. 30 Evidence from the UK suggests that despite being the most likely group of people to have obsolete prescriptions and some form of chronic eye disease, elderly people make insufficient use of eye care facilities. 31 Indeed, surveys suggest that over half the visual impairment in the over 65 age group could potentially be reduced with treatment, notably by refractive correction or cataract surgery. 32 Rehabilitation of the Visually Impaired Rehabilitation involves the assessment of visual impairment and the evaluation of functional performance, such as reading, writing, and mobility, within the context of lifestyle (e.g., employment, family activities), attitudes, and psychological well-being. Rehabilitation goals are defined in terms of what matters most in a person’s life, and attempts are made to solve functional problems through adaptive options (e.g., vision enhancement and substitution devices, environmental modifications) and coping strategies. The research challenge is to develop rehabilitation mechanisms proven to be effective in enhancing quality of life, to determine which approaches are most successful with different types of individuals, and to improve the delivery of these services to those in need. The area of technology and assistive devices is a critically important research area because of its central role in the rehabilitation process. This research focus includes the development of new devices, application of advanced technologies to visual or sensory substitution aids, and the continuous development and exploitation of new technologies, including communication, information, and computer technology. 33,34 It is also essential that research in this area addresses how to optimize training in the effective use of devices, particularly for the elderly. Research is also required that addresses the effects of vision impairment on accessing the environment in the home, the workplace, and while traveling.

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