Low-Vision Rehabilitation with Older Adults Vision loss increases dramatically with age but relatively little attention has been paid to blind and low-vision rehabilitation with older adults in the health care literature. The present article describes the nature and etiology of vision loss in older adults and provides an overview of the techniques and technologies available to help older adults overcome the disabilities associated with loss of vision.
Steven B. Loven, PhD Jon M. Rose, PhD Division of Vision and Aging Geriatric Research Education and Clinical Center Department of Veterans Affairs Medical Center and Division of Endocrinology, Gerontology and Metabolism Department of Medicine Stanford University School of Medicine Palo Alto, CA
Vision loss is one of the most dreaded forms of disability for many people and its prevalence rises dramatically with age. I However, relatively little attention has been given to this subject in the health care literature. At least two factors are responsible for this omission. Vision loss, once it has occurred, can rarely be reversed. This lack of restorative treatment is disheartening to many professionals. Additionally, vision loss often coexists with other diseases of later life that receive more attention from health professionals. I Fortunately, effective rehabilitation techniques and technologies for lessening disabilities resulting from sight loss do exist. The purpose of the present article is to acquaint health care providers who work with older adults about the nature of vision loss in later life and the rehabilitation options available. Specifically, the article: • describes the nature and prevalence of sight loss in older adults. • describes the m3:ior etiologies of sight loss. • presents an overview of current low-vision rehabilitation strategies. • and discusses future directions in the field. NeuroRehabil1993; 3(1):26-33 Copyright © 1993 by Andover Medical.
Low-Vision Rehabilitati.on with Older Adults
DEFINITIONS AND PREVALENCE OF SIGHT LOSS Three broad categories representing degree of vision loss are typically used in the United States. Severe visual impairment is defined as best corrected visual acuity in the better eye between 20/70 and 20/200 or a visual field between 40 degrees and 20 degrees. Legal blindness is defined as best corrected visual acuity of 20/200 or worse in the better eye or a visual field of 20 degrees or less. Individuals wh.o perceive .only changes in light .or do not have even light perception are said t.o be t.otally blind. Estimates of the prevalence of vision loss in the United States have been difficult to obtain. M.ost estimates are based on self-reports and these may be confounded by people's inability to determine if their visual difficulties are correctable. Data from the National Health Interview Survey for 1983 to 1985 indicated that approximately 35.3 people per 1000 were legally blind or had other visual impairments. 2 These rates rise steadily with age. Rates per 1000 were 46.4 for people 45 to 64 years of age, 71.8 for people 65 to 74 years of age, and 136.3 for people 75 years of age and older. Vision loss involves more than loss of visual acuity and field. Older individuals with visual deficits are often sensitive to glare and find bright light uncomfortable or painful but also need more light than normal to maximize the use of their remaining vision. Impairment in contrast sensitivity, the ability to distinguish images against backgrounds of varying degrees of darkness, may create more difficulties for a person than decreases in visual acuity. Decreased contrast sensitivity can interfere with reading of printed material when the printing is light or nonwhite paper is used. It also makes it more difficult to see the edges of steps, curbs, and other changes in elevation. Ability to discriminate colors may be impaired. This increases the difficulty of using color coding of signs and labels and interferes with basic activities of daily living such as clothes selection.
27
ETIOLOGY OF VISION LOSS Cataracts As a person ages, the lens of the eye gradually become more opaque. Less light is able to penetrate the lens and visi.on becomes blurry or hazy. The opacity also defracts incoming light and increases a person's perception of glare. Approximately 97.5 individuals per 1000 between 65 and 74 years of age develop cataracts. The rate jumps to 241.4 per 1000 for individuals 75 years of age and .older. 2 Major problems include greatly reduced night vision, hypersensitivity to glare, and a gradual reduction in visual acuity that can eventually result in blindness. Surgical replacement of the effected lens can restore lost vision. Cataract surgery is one of the most common and effective surgeries performed today. 3 However, cataracts cannot always be removed as soon as they start interfering with daily activities. An individual may have to cope with low vision for several months prior to surgical treatment.
Age-related Macular Degeneration (ARM) ARM causes the destruction of cells in the macular area of the retina. The macula contains the densest concentration of visual receptor cells in the retina. Damage to this area produces a blind spot (scotoma) in the middle of the person's visual field and greatly interferes with tasks requiring high levels of visual precision, such as reading and identifying facial features. Prevalence estimates for ARM suggest that it affects approximately 3% of population over 65. 2 Medical treatment with lasers can slow down the progressi.on of the "wet" subtype of ARM that can cause blindness but is not effective with the more common but less destructive "dry" subtype.
Glaucoma Glaucoma produces an increase in the pressure of the fluids contained in the eye. The pressure gradually destroys cells in the optic nerve, initially causing loss of vision at the periphery of the visual field and gradually progressing inward. Individuals often describe the results as "tunnel vision" and report great difficulty with foot travel and
28
NEUROREHABILITATION / WINTER 1993
other activities requiring a wide field of vision. The disease can eventually cause total blindness. Glaucoma affects at least 97.5 individuals per 1000 in the 65- to 74-year-old age group.! Medication, and occasionally surgery, is used to reduce intraocular pressures, thereby slowing the progress of the disease.
Diabetic Retinopathy The prolonged effects of diabetes can damage the retina through a variety of mechanisms. The damage results in multiple scotomas whose interference with visual functioning is determined by their number, size, and location. Diabetic retinopathy affects 25% of diabetics. 4 The prevalence of the disease is related to the length of time an individual has had diabetes, rising from 50% in the first seven years of the disease to 90% after the disease has been present for 20 to 25 years. Laser treatment is used to slow the progress of the disease.
BLIND AND LOW-VISION REHABILITATION Vision rehabilitation has two major goals: maximizing functional independence and enhancing feelings of self-confidence, self-worth, and satisfaction with life. In many cases, the process of maximizing functional independence results in greater self-confidence and life satisfaction without having to specifically target these areas for intervention. Therefore, the following discussion of vision rehabilitation will begin with the goal of maximizing functional independence. Table 1.
Vision rehabilitation for older adults addresses at least three areas: visual skills, orientation and mobility skills, and daily living skills. Visual skills rehabilitation focuses on maximizing an individual's use of their residual vision. Orientation and mobility training teaches an individual how to orient themselves to their environment and travel safely on foot. Daily living skills is a broad area covering personal care activities such as dressing and personal hygiene as well as instrumental activities such as household management, clothes care, and shopping. Some older individuals with visual impairment may still be working and in need of vocational training. However, many older individuals are retired when they begin to experience sight loss and are not interested in specialized vocational training. Each area of vision rehabilitation employs a variety of techniques to assist individuals in maintaining their functional independence. The techniques fall into three broad categories: modifYing the clients' environments, providing assistive devices, and teaching new skills. Examples of each category of technique and how they are applied to each area of vision rehabilitation are described below and summarized in Table 1.
Visual Skills The purpose of visual skills training is to maximize an individual's use of their residual vision. Much of the research on rehabilitation of low vision focuses on methods of enhancing visual skills. 5-7 The first step is to determine how much vision remains and what conditions are optimal for its
Examples of vision rehabilitation techniques. Techniques
Visual SkilLI Orientation & Mobility Living Skills
Environmental Modifications
Assistive Devices
Skills Training
cover glaring surfaces use contrasting colors use focused lighting create clear pathways
optical magnifier
magnifier use scanning eccentric viewing cane training travel skills cooking, laundry braille
organize work areas tactile labeling
CCTV
typoscopes long cane monoculars talking equipment tape recorders
.
Low-Vision Rehabilitation with Older Adults
use. A low-vision examination is usually conducted by specially trained low-vision optometrists or opthalmologists, sometimes in conjunction with a vision rehabilitaion specialist. A lowvision exam is more involved than the typical eye examinations that are familiar to most of us. 8 Special eye charts are used to obtain finer gradations in visual acuity than those provided by the standard Snellen chart. Visual acuity is measured at the usual 10- or 20-foot distance and again at a standard reading distance. Magnification and lighting may be varied to determine what combination of these elements produces the most useful vision. Other measures of visual functioning obtained include: visual fields, contrast sensitivity, color perception, and glare sensitivity. The complete examination may require 2-3 hours and parts of it may be repeated on different days to assess fluctuation in vision. The results of the initial low-vision examination are used to determine what environmental modifications, visual aids, and types of training are appropriate for a given client. Environmental modifications. Environmental modifications of a client's home or workplace can help to compensate for increased sensitivity to glare, decreased contrast sensitivity, and increased need for illumination. Debilitating glare from shiny surfaces such as floors, counters, and other furniture can be reduced by using throw rugs, tablecloths, or other nonreflective materials. Chairs and television sets can be repositioned so that clients do not face a sunny window (or receive reflected glare from television screens). Individuals with deficits in contrast sensitivity may have difficulty locating objects because they are sitting on surfaces of a similar color. For example, white plates on a white tablecloth may not be visible. Use of contrasting colors, such as a dark tablecloth with white plates can eliminate such a problem. Wall switches and appliance dials may also suffer from low contrast. Outlining a wall switch on a white wall with dark tape (or buying a dark wall plate for the switch) can enhance its visibility. Large print, high-contrast replacement dials for appliances, timers, clocks and other measuring devices are often available free of charge from utility companies for individuals with visual impairments.
29
Many individuals with low vision require intense, focused light on objects in order to see them as clearly as possible. However, the discomfort resulting from glare of the sun through windows or diffused light from lamps impels individuals to cover the windows and use low-wattage bulbs. Instructions to place powerful lamps or sunny windows in back and slightly to the side of objects they wish to see can greatly improve clients' ability to use their remaining vision for precise tasks such as reading labels and looking at pictures. Assistive devices. Assistive devices to enhance remaining vision are usually optical magnifiers. Magnifiers of all kinds are especially helpful for near vision activities such as reading. The magnifiers may be in the form of spectacles, hand-held devices, or mounted on goggle frames such as those used by jewelers. Closed circuit TV systems (CCTV) can be especially useful for some individuals. CCTVs use a video camera connected to a television monitor to enlarge reading material or other objects placed on a platform underneath the camera. It can enlarge material up to 20 times its original size and the contrast can also be adjusted. Telescopic devices can be used to enhance distance vision. Hand-held monoculars or binoculars may be useful for reading signs and viewing other objects at a distance. Small, spectacle mounted telescopes help some individuals watch television, view movies, and engage in other intermediate distance activities. Sunglasses, usually referred to as tints, are very useful aids for nearly all individuals with low vision. There are a large variety of styles and degrees of tint. Some individuals wear yellow tints indoors to reduce glare from overhead lighting. Skills training. Training in the appropriate use of optical aids is needed for simple magnifYing devices as well as more complicated equipment such as the CCTV. Optical aids do not provide individuals with "normal sight." The clarity of images is still reduced but the magnification allows the individual to more easily detect critical elements of the image needed to identifY it. Also, as magnification increases, the field of view decreases. A person may be able to see only a few letters of a word at a time. Unless an individual receives training in the use of even simple vision
30
NEUROREHABILITATION / WINTER 1993
aids, the devices are likely to be put in a drawer after the first several weeks. Two other visual skills that require training for some individuals are scanning and eccentric viewing. Persons with reduced visual fields must learn to compensate by turning their head, or scanning, to cover fields of view previously included in their peripheral vision. Consistent scanning is a habit and most people initially need frequent reminders to practice it. Eccentric viewing is a useful technique for individuals with a central scotoma. It involves learning to look off to the side of an object rather than directly at it. Looking to the side utilizes the unimpaired peripheral vision. This can be a very difficult technique to master because it contradicts our natural tendency to look straight at objects we wish to see. Also, peripheral vision is much less acute than central vision so images always appear somewhat fuzzy.
Orientation and Mobility One of the most difficult, and potentially dangerous, activities for older individuals with low vision is ambulation or foot travel. The inability to see obstacles in one's path, cars approaching an intersection, and traffic lights and other warning signs puts an individual at risk for serious injury. People often find themselves more reliant on foot travel following sight loss than they were before since they can no longer drive. Orientation and mobility (O&M) training may require the most training time of any of the rehabilitation areas for individuals with little or no remaining vision. However, many totally blind individuals who have mastered O&M techniques are capable of traveling independently even in busy city environments. Environmental modification. Modification of the client's home environment can enhance mobility. The basic goal is to establish and maintain clear paths of travel between rooms and between frequently used objects, such as the television. Maintaining clear travel paths is often a difficult task. Sighted family members frequently have difficulty understanding why any movement of furniture, abandoned toys, drawers left open or other minor but unpredictable changes to the home environment can be a hazard to a person with low vision.
Assistive devices. The major aSSlsUve device used for O&M is the long, slender white cane most people have come to associate with blindness. Proper use of the cane greatly enhances travel ability. Experimental devices that use sonic waves to locate objects have been created that can be attached to the long cane or worn like a pair of spectacles. These devices have not yet proven to be sufficiently more effective than the long cane and are not in common use. Monoculars and binoculars for distance viewing are often very useful for reading signs and seeing traffic signals. Older individuals with diseases such as glaucoma may have difficulty traveling by foot due to restrictions in their visual field rather than deficits in visual acuity. Such individuals can sometimes benefit from using a monocular "backwards." Looking through the magnifying end of the monocular, rather than the eye piece, reduces the size of the image at which it is pointed but expands the visual field. This allows individuals with small fields but good acuity to visually explore an area they plan to walk through more thoroughly. This novel use of a monocular complements, rather than replaces, the use of a long cane. Skills training. Training of O&M skills can be very involved and time consuming for individuals with little or no remaining vision. Initially, individuals are taught protective hand positions to avoid injury from bumping into objects in rooms or other small spaces. The next step involves sighted guide training. This is particularly useful for older individuals who typically travel with a sighted companion. A standard series of techniques allows the sighted person to guide the individual with visual impairment while he or she is grasping the sighted person's arm just above the elbow. Training with the long cane is the most involved. A variety of techniques for using the cane are available depending on the type and degree of visual impairment and the amount and complexity of foot travel in which the person wishes to engage. O&M rehabilitation is a speciality area for vision rehabilitation specialists and has its own credentialing body.
Low-Vision Rehabilitation with Older Adults
Living Skills Environmental modification. Organizing the home and work environment is probably the most powerful technique for minimizing the problem of being unable to locate items visually. Furniture, appliances, and other objects in a room can be arranged to fucilitate mobility and their ease of use. Systems for organizing clothes, food, medicines, and other daily essentials have been developed. For example, paper currency can be folded in specific ways to indicate the denomination of the bill. Tactile markings can be added to appliance dials and switches to replace or supplement the visual markings. Assistive devices. Sound output has been added to a number of everyday devices. It is possible to buy talking clocks, watches, and calculators. Special devices are available to help diabetics load their insulin syringes even if they are unable to read markings on the syringe. It is now possible to use computers without being able to see the screen, although the equipment and software are still quite expensive. Computer-based text scanning and speech synthesizers have also made it possible to create reading machines. One of the most useful and satisfying devices available for people who like to read but are unable to do so are talking book recorders. The talking book program is run by the Library of Congress. It provides books on special four-track tape. Visually impaired individuals are provided a special player and a catalogue that allows them to borrow tapes through the mail. There are nonoptical devices that can enhance an individual's ability to use their remaining vision. Typoscopes are pieces of thin black cardboard in which holes have been cut to highlight one line of text on a page or outline the places on a check in which information needs to be filled in. This makes it much easier to follow a line on the page when reading or writing. Skills training. Skills training is an essential component of rehabilitation in daily living skills. Instruction and practice are needed to master devices such as talking calculators. Typing can be a very useful method of written communication but requires extensive instruction if an older adult has not previously learned the skill. As vision de-
31
creases, the need to be organized and meticulous in one's daily activities increases. Previously simple activities such as locating one's wallet, a specific can of food in the cupboard, or other such common items can become an impossible task if they are not consistently placed in a predesignated spot. Older adults who are totally blind can learn braille as a substitute for printed material. However, braille is difficult to learn and many individuals choose to rely on other techniques for record keeping.
SOURCES FOR ASSISTIVE DEVICES AND INFORMATION ABOUT VISUAL IMPAIRMENT Many rehabilitation professionals come into contact with older adults that are at least mildly disabled from visual impairments. In some communities, vision rehabilitation services may not be readily available and it falls upon the rehabilitation professional to provide basic assistance in the management of the disability resulting from the vision loss. Two organizations can provide invaluable help in obtaining information and adaptive devices useful for visually impaired individuals. Their names and addresses are provided below. American Federation for the Blind 15 West 16th Street New York, NY 100 II Lighthouse National Center for Vision and Aging 800 Second Avenue New York, NY 10017
ADDRESSING MOTIVATION AND MOOD It would surprise no one to discover that older adults who suffer progressive vision loss experience decreased mood and self-esteem. However, there is no data to suggest that depression, anxiety, or other psychological disturbances are any more common among older individuals with vision loss than in the general population. The
32
NEUROREHABILITATION / WINTF..R 1993
distress accompanying vision loss is frequently based on fears of increasing dependency and these fears are often laid to rest as an individual gains confidence in his or her ability to remain independent. Occasionally, older individuals have difficulty becoming engaged in the rehabilitation process. They may not have confidence that they can learn new skills or appropriately use the low-vision aids prescribed. Some individuals believe that any rehabilitation that does not lead to "normal sight" will not enhance the quality of their life. There are a number of strategies that are frequently effective in overcoming these barriers to participation in lowvision rehabilitation. Older individuals who lack confidence in their ability to learn new skills can benefit from a slower than usual pace at the beginning of rehabilitation. Once they have been successful in learning one new task, their confidence often increases dramatically and the pace of rehabilitation can be increased. Clients who are not convinced that low-vision rehabilitation will improve their quality of life often respond well if the initial rehabilitation activity is one of great interest to him or her. Sometimes the activity of interest to the client is not one that the staff believes is the most urgent or the logical point at which to begin rehabilitation. One client at our center urgently needed orientation and mobility training but refused to participate in it. However, he was very interested in being able to watch television. Rather than continuing to try and convince him of the usefulness of orientation and mobility training, rehabilitation focused on the use of a sportocular for television viewing. The client worked diligently on this task and was quite successful with it. He then decided that the orientation and mobility training might be useful and willing applied himself to the training. Exposure to other individuals with low vision often enhances motivation for rehabilitation in older clients. Inpatient low-vision rehabilitation programs provide substantial opportunity for this kind of interaction. Outpatient programs provide similar opportunities through support groups, social activities, and group training ses-
sions in activities such as meal preparation and orientation and mobility. Involvement of family members is a powerful method of enhancing clients' motivation. Family members can hinder progress in rehabilitation by insisting that they perform activities for the client that the client has learned to perform independently. Conversely, family members may expect low-vision rehabilitation to eliminate all the limitations experienced by the client as a result of his or her low vision. Including family members in low-vision rehabilitation helps them establish realistic expectations about the course of treatment and provides an understanding of the new skills being learned by the client. A few individuals with low vision may experience clinical levels of depression and anxiety. Such individuals may need professional counseling before they can effectively participate in low-vision rehabilitation. Brief methods of treating affective disorders are available and can be effectively applied to the distress associated with loss of vision. 9
FUTURE DIRECTIONS Medical research continues to search for effective treatments for the eye diseases primarily responsible for vision loss in the older population. Hopefully, other treatment~ as effective as cataract surgery will be discovered but it does not appear likely that this will happen soon. Rapid advances in optical character and voice recognition and voice synthesis are opening the way for effective and affordable reading devices and voice-controlled interfaces with other types of equipment. This technology may greatly reduce the handicaps experienced by visually impaired individuals in our visually oriented society. An extremely important issue surrounding vision loss in older adults is the manner in which it is treated within the U.S. health care system. Most forms of vision rehabilitation are not covered by private insurance, Medicare, or Medicaid. State funds for vision rehabilitation are typically focused on vocational rehabilitation and are therefore not available to most older individuals with sight loss.
Low-Vision Rehabilitation with Older Adults
Community agencies providing vision rehabilitation are usually dependent on donations for their support and rarely have the funds to provide the amount and type of service needed in their community. The Department of Veterans Affairs operates a nationwide system of inpatient Blind Rehabilitation Centers and Clinics that provides vision rehabilitation to legally blind veterans of all ages. However, the tremendous demand for these
33
services far exceeds the system's capacity. Continuing educational and political efforts are needed to inform the government and insurance industry of the extent of visual disability and its consequences in the older population. Vision rehabilitation must be accepted as an important and cost-effective method of decreasing disability and improving quality oflife if it is ever to be available to the older individuals who need it.
REFERENCES 1. LaPlante MP. Data on disability from the National Health Interview Survey, 1983-1985. An InfoUse Report. Washington, D.C.: U.S. National Institute on Disability and Rehabilitation Research, 1988. 2. National Center for Health Statistics. Prevalence of selected chronic conditions, United St.ates, 1983-85. Hyattsville, MD: National Center for Health Statistics 1988. (Advance Data from Vital and Health Statistics. No. 155) DHHS publication no. 88-1250. 3. Javitt JC, Vitale S, Canner JK, et al. National outcome of cataract extraction I: retinal detachment after inpatient surgery. Opthalmology 1991; 98:895-902. 4. Marks R. Eye diseases of people with diabetes. Aging and Vision News 1990; 3:1-2. 5. Gianutsos R, Ramsey G, Perlin RR. Rehabilita-
6.
7.
8.
9.
tive optometric services for survivors of acquired brain injury. Archives of Physical Medicine and Rehabilitation 1988; 69:573-578. McMahon 1'1', Hansen M. Treatment of low vision in the progessive cone dystrophies. American Journal of Optometry and Physiologic Optics 1988; 65:909-914. Nilsson UL. Visual rehabilitation of patients with advanced stages of glaucoma, optic atrophy, myopia or retinitis pigmentosa. Documenta Ophthalmologica 1989; 70:363-383. Jose R. Minimum assessment sequence: the optometrist's point of view. In: Jose R, ed. Understanding low vision. New York: American Federation for the Blind, 1983. Lovett S. Adaptation to vision loss: a cognitive/ behavioral perspective. J of Visual Impairment and Blindness 1988; 2:29-35.
Steven B. Loven, PhD Jon M. Rose, PhD Division of Vision and Aging Geriatric Research Education and Clinical Center Department of Veterans Affairs Medical Center and Division of Endocrinology, Gerontology and Metabolism Department of Medicine Stanford University School of Medicine Palo Alto, CA
Vision loss is one of the most dreaded forms of disability for many people and its prevalence rises dramatically with age. I However, relatively little attention has been given to this subject in the health care literature. At least two factors are responsible for this omission. Vision loss, once it has occurred, can rarely be reversed. This lack of restorative treatment is disheartening to many professionals. Additionally, vision loss often coexists with other diseases of later life that receive more attention from health professionals. I Fortunately, effective rehabilitation techniques and technologies for lessening disabilities resulting from sight loss do exist. The purpose of the present article is to acquaint health care providers who work with older adults about the nature of vision loss in later life and the rehabilitation options available. Specifically, the article: • describes the nature and prevalence of sight loss in older adults. • describes the m3:ior etiologies of sight loss. • presents an overview of current low-vision rehabilitation strategies. • and discusses future directions in the field. NeuroRehabil1993; 3(1):26-33 Copyright © 1993 by Andover Medical.
Low-Vision Rehabilitati.on with Older Adults
DEFINITIONS AND PREVALENCE OF SIGHT LOSS Three broad categories representing degree of vision loss are typically used in the United States. Severe visual impairment is defined as best corrected visual acuity in the better eye between 20/70 and 20/200 or a visual field between 40 degrees and 20 degrees. Legal blindness is defined as best corrected visual acuity of 20/200 or worse in the better eye or a visual field of 20 degrees or less. Individuals wh.o perceive .only changes in light .or do not have even light perception are said t.o be t.otally blind. Estimates of the prevalence of vision loss in the United States have been difficult to obtain. M.ost estimates are based on self-reports and these may be confounded by people's inability to determine if their visual difficulties are correctable. Data from the National Health Interview Survey for 1983 to 1985 indicated that approximately 35.3 people per 1000 were legally blind or had other visual impairments. 2 These rates rise steadily with age. Rates per 1000 were 46.4 for people 45 to 64 years of age, 71.8 for people 65 to 74 years of age, and 136.3 for people 75 years of age and older. Vision loss involves more than loss of visual acuity and field. Older individuals with visual deficits are often sensitive to glare and find bright light uncomfortable or painful but also need more light than normal to maximize the use of their remaining vision. Impairment in contrast sensitivity, the ability to distinguish images against backgrounds of varying degrees of darkness, may create more difficulties for a person than decreases in visual acuity. Decreased contrast sensitivity can interfere with reading of printed material when the printing is light or nonwhite paper is used. It also makes it more difficult to see the edges of steps, curbs, and other changes in elevation. Ability to discriminate colors may be impaired. This increases the difficulty of using color coding of signs and labels and interferes with basic activities of daily living such as clothes selection.
27
ETIOLOGY OF VISION LOSS Cataracts As a person ages, the lens of the eye gradually become more opaque. Less light is able to penetrate the lens and visi.on becomes blurry or hazy. The opacity also defracts incoming light and increases a person's perception of glare. Approximately 97.5 individuals per 1000 between 65 and 74 years of age develop cataracts. The rate jumps to 241.4 per 1000 for individuals 75 years of age and .older. 2 Major problems include greatly reduced night vision, hypersensitivity to glare, and a gradual reduction in visual acuity that can eventually result in blindness. Surgical replacement of the effected lens can restore lost vision. Cataract surgery is one of the most common and effective surgeries performed today. 3 However, cataracts cannot always be removed as soon as they start interfering with daily activities. An individual may have to cope with low vision for several months prior to surgical treatment.
Age-related Macular Degeneration (ARM) ARM causes the destruction of cells in the macular area of the retina. The macula contains the densest concentration of visual receptor cells in the retina. Damage to this area produces a blind spot (scotoma) in the middle of the person's visual field and greatly interferes with tasks requiring high levels of visual precision, such as reading and identifying facial features. Prevalence estimates for ARM suggest that it affects approximately 3% of population over 65. 2 Medical treatment with lasers can slow down the progressi.on of the "wet" subtype of ARM that can cause blindness but is not effective with the more common but less destructive "dry" subtype.
Glaucoma Glaucoma produces an increase in the pressure of the fluids contained in the eye. The pressure gradually destroys cells in the optic nerve, initially causing loss of vision at the periphery of the visual field and gradually progressing inward. Individuals often describe the results as "tunnel vision" and report great difficulty with foot travel and
28
NEUROREHABILITATION / WINTER 1993
other activities requiring a wide field of vision. The disease can eventually cause total blindness. Glaucoma affects at least 97.5 individuals per 1000 in the 65- to 74-year-old age group.! Medication, and occasionally surgery, is used to reduce intraocular pressures, thereby slowing the progress of the disease.
Diabetic Retinopathy The prolonged effects of diabetes can damage the retina through a variety of mechanisms. The damage results in multiple scotomas whose interference with visual functioning is determined by their number, size, and location. Diabetic retinopathy affects 25% of diabetics. 4 The prevalence of the disease is related to the length of time an individual has had diabetes, rising from 50% in the first seven years of the disease to 90% after the disease has been present for 20 to 25 years. Laser treatment is used to slow the progress of the disease.
BLIND AND LOW-VISION REHABILITATION Vision rehabilitation has two major goals: maximizing functional independence and enhancing feelings of self-confidence, self-worth, and satisfaction with life. In many cases, the process of maximizing functional independence results in greater self-confidence and life satisfaction without having to specifically target these areas for intervention. Therefore, the following discussion of vision rehabilitation will begin with the goal of maximizing functional independence. Table 1.
Vision rehabilitation for older adults addresses at least three areas: visual skills, orientation and mobility skills, and daily living skills. Visual skills rehabilitation focuses on maximizing an individual's use of their residual vision. Orientation and mobility training teaches an individual how to orient themselves to their environment and travel safely on foot. Daily living skills is a broad area covering personal care activities such as dressing and personal hygiene as well as instrumental activities such as household management, clothes care, and shopping. Some older individuals with visual impairment may still be working and in need of vocational training. However, many older individuals are retired when they begin to experience sight loss and are not interested in specialized vocational training. Each area of vision rehabilitation employs a variety of techniques to assist individuals in maintaining their functional independence. The techniques fall into three broad categories: modifYing the clients' environments, providing assistive devices, and teaching new skills. Examples of each category of technique and how they are applied to each area of vision rehabilitation are described below and summarized in Table 1.
Visual Skills The purpose of visual skills training is to maximize an individual's use of their residual vision. Much of the research on rehabilitation of low vision focuses on methods of enhancing visual skills. 5-7 The first step is to determine how much vision remains and what conditions are optimal for its
Examples of vision rehabilitation techniques. Techniques
Visual SkilLI Orientation & Mobility Living Skills
Environmental Modifications
Assistive Devices
Skills Training
cover glaring surfaces use contrasting colors use focused lighting create clear pathways
optical magnifier
magnifier use scanning eccentric viewing cane training travel skills cooking, laundry braille
organize work areas tactile labeling
CCTV
typoscopes long cane monoculars talking equipment tape recorders
.
Low-Vision Rehabilitation with Older Adults
use. A low-vision examination is usually conducted by specially trained low-vision optometrists or opthalmologists, sometimes in conjunction with a vision rehabilitaion specialist. A lowvision exam is more involved than the typical eye examinations that are familiar to most of us. 8 Special eye charts are used to obtain finer gradations in visual acuity than those provided by the standard Snellen chart. Visual acuity is measured at the usual 10- or 20-foot distance and again at a standard reading distance. Magnification and lighting may be varied to determine what combination of these elements produces the most useful vision. Other measures of visual functioning obtained include: visual fields, contrast sensitivity, color perception, and glare sensitivity. The complete examination may require 2-3 hours and parts of it may be repeated on different days to assess fluctuation in vision. The results of the initial low-vision examination are used to determine what environmental modifications, visual aids, and types of training are appropriate for a given client. Environmental modifications. Environmental modifications of a client's home or workplace can help to compensate for increased sensitivity to glare, decreased contrast sensitivity, and increased need for illumination. Debilitating glare from shiny surfaces such as floors, counters, and other furniture can be reduced by using throw rugs, tablecloths, or other nonreflective materials. Chairs and television sets can be repositioned so that clients do not face a sunny window (or receive reflected glare from television screens). Individuals with deficits in contrast sensitivity may have difficulty locating objects because they are sitting on surfaces of a similar color. For example, white plates on a white tablecloth may not be visible. Use of contrasting colors, such as a dark tablecloth with white plates can eliminate such a problem. Wall switches and appliance dials may also suffer from low contrast. Outlining a wall switch on a white wall with dark tape (or buying a dark wall plate for the switch) can enhance its visibility. Large print, high-contrast replacement dials for appliances, timers, clocks and other measuring devices are often available free of charge from utility companies for individuals with visual impairments.
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Many individuals with low vision require intense, focused light on objects in order to see them as clearly as possible. However, the discomfort resulting from glare of the sun through windows or diffused light from lamps impels individuals to cover the windows and use low-wattage bulbs. Instructions to place powerful lamps or sunny windows in back and slightly to the side of objects they wish to see can greatly improve clients' ability to use their remaining vision for precise tasks such as reading labels and looking at pictures. Assistive devices. Assistive devices to enhance remaining vision are usually optical magnifiers. Magnifiers of all kinds are especially helpful for near vision activities such as reading. The magnifiers may be in the form of spectacles, hand-held devices, or mounted on goggle frames such as those used by jewelers. Closed circuit TV systems (CCTV) can be especially useful for some individuals. CCTVs use a video camera connected to a television monitor to enlarge reading material or other objects placed on a platform underneath the camera. It can enlarge material up to 20 times its original size and the contrast can also be adjusted. Telescopic devices can be used to enhance distance vision. Hand-held monoculars or binoculars may be useful for reading signs and viewing other objects at a distance. Small, spectacle mounted telescopes help some individuals watch television, view movies, and engage in other intermediate distance activities. Sunglasses, usually referred to as tints, are very useful aids for nearly all individuals with low vision. There are a large variety of styles and degrees of tint. Some individuals wear yellow tints indoors to reduce glare from overhead lighting. Skills training. Training in the appropriate use of optical aids is needed for simple magnifYing devices as well as more complicated equipment such as the CCTV. Optical aids do not provide individuals with "normal sight." The clarity of images is still reduced but the magnification allows the individual to more easily detect critical elements of the image needed to identifY it. Also, as magnification increases, the field of view decreases. A person may be able to see only a few letters of a word at a time. Unless an individual receives training in the use of even simple vision
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NEUROREHABILITATION / WINTER 1993
aids, the devices are likely to be put in a drawer after the first several weeks. Two other visual skills that require training for some individuals are scanning and eccentric viewing. Persons with reduced visual fields must learn to compensate by turning their head, or scanning, to cover fields of view previously included in their peripheral vision. Consistent scanning is a habit and most people initially need frequent reminders to practice it. Eccentric viewing is a useful technique for individuals with a central scotoma. It involves learning to look off to the side of an object rather than directly at it. Looking to the side utilizes the unimpaired peripheral vision. This can be a very difficult technique to master because it contradicts our natural tendency to look straight at objects we wish to see. Also, peripheral vision is much less acute than central vision so images always appear somewhat fuzzy.
Orientation and Mobility One of the most difficult, and potentially dangerous, activities for older individuals with low vision is ambulation or foot travel. The inability to see obstacles in one's path, cars approaching an intersection, and traffic lights and other warning signs puts an individual at risk for serious injury. People often find themselves more reliant on foot travel following sight loss than they were before since they can no longer drive. Orientation and mobility (O&M) training may require the most training time of any of the rehabilitation areas for individuals with little or no remaining vision. However, many totally blind individuals who have mastered O&M techniques are capable of traveling independently even in busy city environments. Environmental modification. Modification of the client's home environment can enhance mobility. The basic goal is to establish and maintain clear paths of travel between rooms and between frequently used objects, such as the television. Maintaining clear travel paths is often a difficult task. Sighted family members frequently have difficulty understanding why any movement of furniture, abandoned toys, drawers left open or other minor but unpredictable changes to the home environment can be a hazard to a person with low vision.
Assistive devices. The major aSSlsUve device used for O&M is the long, slender white cane most people have come to associate with blindness. Proper use of the cane greatly enhances travel ability. Experimental devices that use sonic waves to locate objects have been created that can be attached to the long cane or worn like a pair of spectacles. These devices have not yet proven to be sufficiently more effective than the long cane and are not in common use. Monoculars and binoculars for distance viewing are often very useful for reading signs and seeing traffic signals. Older individuals with diseases such as glaucoma may have difficulty traveling by foot due to restrictions in their visual field rather than deficits in visual acuity. Such individuals can sometimes benefit from using a monocular "backwards." Looking through the magnifying end of the monocular, rather than the eye piece, reduces the size of the image at which it is pointed but expands the visual field. This allows individuals with small fields but good acuity to visually explore an area they plan to walk through more thoroughly. This novel use of a monocular complements, rather than replaces, the use of a long cane. Skills training. Training of O&M skills can be very involved and time consuming for individuals with little or no remaining vision. Initially, individuals are taught protective hand positions to avoid injury from bumping into objects in rooms or other small spaces. The next step involves sighted guide training. This is particularly useful for older individuals who typically travel with a sighted companion. A standard series of techniques allows the sighted person to guide the individual with visual impairment while he or she is grasping the sighted person's arm just above the elbow. Training with the long cane is the most involved. A variety of techniques for using the cane are available depending on the type and degree of visual impairment and the amount and complexity of foot travel in which the person wishes to engage. O&M rehabilitation is a speciality area for vision rehabilitation specialists and has its own credentialing body.
Low-Vision Rehabilitation with Older Adults
Living Skills Environmental modification. Organizing the home and work environment is probably the most powerful technique for minimizing the problem of being unable to locate items visually. Furniture, appliances, and other objects in a room can be arranged to fucilitate mobility and their ease of use. Systems for organizing clothes, food, medicines, and other daily essentials have been developed. For example, paper currency can be folded in specific ways to indicate the denomination of the bill. Tactile markings can be added to appliance dials and switches to replace or supplement the visual markings. Assistive devices. Sound output has been added to a number of everyday devices. It is possible to buy talking clocks, watches, and calculators. Special devices are available to help diabetics load their insulin syringes even if they are unable to read markings on the syringe. It is now possible to use computers without being able to see the screen, although the equipment and software are still quite expensive. Computer-based text scanning and speech synthesizers have also made it possible to create reading machines. One of the most useful and satisfying devices available for people who like to read but are unable to do so are talking book recorders. The talking book program is run by the Library of Congress. It provides books on special four-track tape. Visually impaired individuals are provided a special player and a catalogue that allows them to borrow tapes through the mail. There are nonoptical devices that can enhance an individual's ability to use their remaining vision. Typoscopes are pieces of thin black cardboard in which holes have been cut to highlight one line of text on a page or outline the places on a check in which information needs to be filled in. This makes it much easier to follow a line on the page when reading or writing. Skills training. Skills training is an essential component of rehabilitation in daily living skills. Instruction and practice are needed to master devices such as talking calculators. Typing can be a very useful method of written communication but requires extensive instruction if an older adult has not previously learned the skill. As vision de-
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creases, the need to be organized and meticulous in one's daily activities increases. Previously simple activities such as locating one's wallet, a specific can of food in the cupboard, or other such common items can become an impossible task if they are not consistently placed in a predesignated spot. Older adults who are totally blind can learn braille as a substitute for printed material. However, braille is difficult to learn and many individuals choose to rely on other techniques for record keeping.
SOURCES FOR ASSISTIVE DEVICES AND INFORMATION ABOUT VISUAL IMPAIRMENT Many rehabilitation professionals come into contact with older adults that are at least mildly disabled from visual impairments. In some communities, vision rehabilitation services may not be readily available and it falls upon the rehabilitation professional to provide basic assistance in the management of the disability resulting from the vision loss. Two organizations can provide invaluable help in obtaining information and adaptive devices useful for visually impaired individuals. Their names and addresses are provided below. American Federation for the Blind 15 West 16th Street New York, NY 100 II Lighthouse National Center for Vision and Aging 800 Second Avenue New York, NY 10017
ADDRESSING MOTIVATION AND MOOD It would surprise no one to discover that older adults who suffer progressive vision loss experience decreased mood and self-esteem. However, there is no data to suggest that depression, anxiety, or other psychological disturbances are any more common among older individuals with vision loss than in the general population. The
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NEUROREHABILITATION / WINTF..R 1993
distress accompanying vision loss is frequently based on fears of increasing dependency and these fears are often laid to rest as an individual gains confidence in his or her ability to remain independent. Occasionally, older individuals have difficulty becoming engaged in the rehabilitation process. They may not have confidence that they can learn new skills or appropriately use the low-vision aids prescribed. Some individuals believe that any rehabilitation that does not lead to "normal sight" will not enhance the quality of their life. There are a number of strategies that are frequently effective in overcoming these barriers to participation in lowvision rehabilitation. Older individuals who lack confidence in their ability to learn new skills can benefit from a slower than usual pace at the beginning of rehabilitation. Once they have been successful in learning one new task, their confidence often increases dramatically and the pace of rehabilitation can be increased. Clients who are not convinced that low-vision rehabilitation will improve their quality of life often respond well if the initial rehabilitation activity is one of great interest to him or her. Sometimes the activity of interest to the client is not one that the staff believes is the most urgent or the logical point at which to begin rehabilitation. One client at our center urgently needed orientation and mobility training but refused to participate in it. However, he was very interested in being able to watch television. Rather than continuing to try and convince him of the usefulness of orientation and mobility training, rehabilitation focused on the use of a sportocular for television viewing. The client worked diligently on this task and was quite successful with it. He then decided that the orientation and mobility training might be useful and willing applied himself to the training. Exposure to other individuals with low vision often enhances motivation for rehabilitation in older clients. Inpatient low-vision rehabilitation programs provide substantial opportunity for this kind of interaction. Outpatient programs provide similar opportunities through support groups, social activities, and group training ses-
sions in activities such as meal preparation and orientation and mobility. Involvement of family members is a powerful method of enhancing clients' motivation. Family members can hinder progress in rehabilitation by insisting that they perform activities for the client that the client has learned to perform independently. Conversely, family members may expect low-vision rehabilitation to eliminate all the limitations experienced by the client as a result of his or her low vision. Including family members in low-vision rehabilitation helps them establish realistic expectations about the course of treatment and provides an understanding of the new skills being learned by the client. A few individuals with low vision may experience clinical levels of depression and anxiety. Such individuals may need professional counseling before they can effectively participate in low-vision rehabilitation. Brief methods of treating affective disorders are available and can be effectively applied to the distress associated with loss of vision. 9
FUTURE DIRECTIONS Medical research continues to search for effective treatments for the eye diseases primarily responsible for vision loss in the older population. Hopefully, other treatment~ as effective as cataract surgery will be discovered but it does not appear likely that this will happen soon. Rapid advances in optical character and voice recognition and voice synthesis are opening the way for effective and affordable reading devices and voice-controlled interfaces with other types of equipment. This technology may greatly reduce the handicaps experienced by visually impaired individuals in our visually oriented society. An extremely important issue surrounding vision loss in older adults is the manner in which it is treated within the U.S. health care system. Most forms of vision rehabilitation are not covered by private insurance, Medicare, or Medicaid. State funds for vision rehabilitation are typically focused on vocational rehabilitation and are therefore not available to most older individuals with sight loss.
Low-Vision Rehabilitation with Older Adults
Community agencies providing vision rehabilitation are usually dependent on donations for their support and rarely have the funds to provide the amount and type of service needed in their community. The Department of Veterans Affairs operates a nationwide system of inpatient Blind Rehabilitation Centers and Clinics that provides vision rehabilitation to legally blind veterans of all ages. However, the tremendous demand for these
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services far exceeds the system's capacity. Continuing educational and political efforts are needed to inform the government and insurance industry of the extent of visual disability and its consequences in the older population. Vision rehabilitation must be accepted as an important and cost-effective method of decreasing disability and improving quality oflife if it is ever to be available to the older individuals who need it.
REFERENCES 1. LaPlante MP. Data on disability from the National Health Interview Survey, 1983-1985. An InfoUse Report. Washington, D.C.: U.S. National Institute on Disability and Rehabilitation Research, 1988. 2. National Center for Health Statistics. Prevalence of selected chronic conditions, United St.ates, 1983-85. Hyattsville, MD: National Center for Health Statistics 1988. (Advance Data from Vital and Health Statistics. No. 155) DHHS publication no. 88-1250. 3. Javitt JC, Vitale S, Canner JK, et al. National outcome of cataract extraction I: retinal detachment after inpatient surgery. Opthalmology 1991; 98:895-902. 4. Marks R. Eye diseases of people with diabetes. Aging and Vision News 1990; 3:1-2. 5. Gianutsos R, Ramsey G, Perlin RR. Rehabilita-
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tive optometric services for survivors of acquired brain injury. Archives of Physical Medicine and Rehabilitation 1988; 69:573-578. McMahon 1'1', Hansen M. Treatment of low vision in the progessive cone dystrophies. American Journal of Optometry and Physiologic Optics 1988; 65:909-914. Nilsson UL. Visual rehabilitation of patients with advanced stages of glaucoma, optic atrophy, myopia or retinitis pigmentosa. Documenta Ophthalmologica 1989; 70:363-383. Jose R. Minimum assessment sequence: the optometrist's point of view. In: Jose R, ed. Understanding low vision. New York: American Federation for the Blind, 1983. Lovett S. Adaptation to vision loss: a cognitive/ behavioral perspective. J of Visual Impairment and Blindness 1988; 2:29-35.
