by Debra Busacco, PhD
Considerations for patients who have hearing and vision problems.
As many as 1 in 5 people ages 70 years or older have both hearing and vision loss. This article examines dual sensory loss, and provides recommendations for better serving the needs of this unique and growing patient population.
The demographics of the world population are changing, with the segment of adults 65 years of age and older growing rapidly. By 2040, it is estimated that older adults will constitute 20% of the US population.
As people age, there are normal age-related changes in the auditory and visual mechanisms. Dual sensory loss—or hearing and vision loss combined is increasing and will continue to do so as the number of seniors grows during the next several decades. As a result, hearing care providers need to ensure that their services are accessible to this segment of the population.
Debra Busacco, PhD is a national audiology consultant based in the greater Washington, DC area, and an adjunct professor teaching online classes in health care management for Trident International University. She is the former director of the George S. Osborne College of Audiology at Salus University in Philadelphia, and has also worked as director of the Center for Teaching and Learning Excellence at the University of Scranton (Pa) and as the director of academic affairs at the American Speech Language Hearing Association (ASHA), Rockville, Md.
In dual sensory loss, the degree of vision and hearing loss is reported to be significant enough to result in communication problems that go beyond difficulties experienced for either sensory loss alone.2 Estimates of the percentage of people with dual sensory loss in those age 70 years and older range between 9% to 21%.3 The incidence of dual sensory loss varies, depending on the definitions used to define hearing loss and vision loss, as well as on the method of data collection.
Age-Related Sensory Changes
Hearing loss is the third most chronic health condition affecting older adults. Approximately 30% of those over age 65 have some degree of hearing loss, with estimates ranging from 70% to 90% of those over age 85, which is the fastest growing segment of the population in the world.4
Presbycusis, age-related changes in auditory function, is caused by anatomical and physiological changes to the entire auditory pathway.5 However, the aging of the auditory system is not uniform throughout the mechanism. Age-related changes in the peripheral and central auditory pathways impact speech understanding ability, especially in degraded listening conditions, such as in the presence of noise, reverberation, or temporally-altered speech.6
Age-related changes in the visual mechanism are known as presbyopia. Normal age-related changes in vision include decrease in pupil size, loss of color sensitivity, glare sensitivity, delayed ability to adapt to the dark, reduced peripheral visual fields, and loss of depth perception.7
Approximately 10% of Americans are legally blind. The definition of legal blindness is visual acuity with the best correction in the better eye equal to or worse than 20/200, visual fields less than 20°, or both. About 3 million Americans are reported to have low vision—a term implying that an individual has significant vision loss but can accomplish tasks with the use of assistive technology and environmental modifications.8
Causes of Low Vision in Older Adults
The four most-common causes of vision loss are age-related macular degeneration, diabetic retinopathy, cataract, and glaucoma:9
Age-related macular may take one of two forms; dry macular degeneration and wet macular degeneration. Dry macular degeneration is more common, and is associated with deposits of drusen (tiny yellow or white accumulations of extracellular material) on the macula. Wet macular degeneration is characterized by the formation of abnormal blood vessels that leak fluid and cause scar tissue to form on the macula. degeneration
Age-related macular degeneration results in a loss of vision to the central visual fields. This disorder has significant implications for speechreading and sign language, as fine details may not be visible. Age-related macular degeneration also may cause problems reading fine print, seeing faces, viewing objects at a distance, and possibly some delay in adapting to the dark.10
Diabetic retinopathy will continue to be a growing problem due to the 23 million Americans diagnosed with Type 2 diabetes, and many more individuals who will be diagnosed in the future. In uncontrolled diabetes, there are problems with the capillaries of the blood vessels in the eyes. This results in problems related to decreases in visual acuity, blurred or hazy vision, glare sensitivity, decreases in contrast sensitivity, and decreases in color discrimination.11
Cataracts result in blurred visual acuity, and can impact all facets of vision depending on the stage of the ocular disease. Typically, cataracts are binocular. Cataracts are removed with a surgical procedure that generally restores vision to normal or near normal. If left untreated, a cataract can cause permanent blindness.10
Glaucoma is the result of an increase in the intraocular pressure in the eye, which can result in degeneration of the optic nerve. Untreated glaucoma can result in permanent blindness. This eye disease impacts visual acuity and visual fields, depending on the stage of the disease.10
These ocular conditions may exist in isolation or coexist. For example, a diabetic may have diabetic retinopathy, and glaucoma or cataracts. The subpopulation of older adults who have a pathological condition as well as normal age-related visual changes may report significant impact on communication abilities, especially if they are not able to use visual cues to compensate for degraded auditory information.
Dual Sensory Loss Individuals with dual sensory loss report poorer self-health, depression, reduced quality of life, and less interaction with social networks.12 Older adults with dual sensory loss are more likely than their non-impaired peers to need help with instrumental activities of daily living, such as personal care, medication management, or phone use. They also are more likely to need help with mobility and shopping, and are more likely to live with family members.13
People with dual sensory loss may have greater risks for falls than those with single sensory loss. This is a significant problem for the elderly, as falls are the third leading cause of death in this population.14 While balance typically is considered a vestibular function, vision and somatosensory information also play a significant role. Professionals should observe patients for balance issues, as well as review this area during the case history intake. When a balance problem is present, the clinician should refer the individual to an appropriate health care professional and work in conjunction with the vision specialist (and, possibly, a physical therapist) to design the most appropriate intervention plan. Orientation and mobility training should address falls and fall prevention to avoid injuries that can be devastating for seniors with coexisting conditions.15
Amplification and implant technologies. When dealing with dual sensory loss, it is imperative that information is maximized through each sensory system so that additional auditory and visual compensatory cues are available. It is critical that an older adult with dual sensory loss obtain amplification for safety and to improve their quality of life. Amplification should include bilateral hearing aids coupled, whenever possible, with a personal listening device, such as an FM or infrared system. The controls on the hearing aid should be minimal with as many automatic features as possible.7
Recently, a programmable hearing instrument, the JZ, was introduced by Panasonic Corporation of North America.16 It was introduced with the target market as older adults with vision and/or motoric problems. The JZ is easy to operate, as it has large controls and a large LCD screen. In addition, it has a rechargeable battery so battery insertion is not problematic. The JZ requires minimal training for the client and caregiver. It has four different programs with features such as noise reduction, feedback suppression, and wind noise management.
Weinstein4 stated that cochlear implants, preferably bilateral, should be considered for those older adults who meet the qualifying criteria. Following cochlear implantation, a comprehensive auditory rehabilitation program that includes auditory-visual speech perception training, listening training, and communication skills enhancement such as cued speech to supplement audition and psychosocial counseling should be implemented.
Hearing assistive devices. The recommendation of a variety of visual and auditory devices makes seniors more confident, and often allows them to live independently. Wireless pagers used in the home can help with identification of environmental sounds, such as smoke alarms, alarm clocks, telephones, and doorbells. A hearing dog can help a person identify sounds, increase independence, and live safely.
AR program A comprehensive auditory rehabilitation program should be developed and implemented in consultation with family, significant others, and professionals using an interdisciplinary team approach. Professionals who may be members of the team include a low vision specialist, geriatrician, occupational therapist, social worker, physical therapist, psychologist, and speech-language pathologist. The members of the interdisciplinary team will vary depending on the unique medical and rehabilitation needs of the older adult and the family.
Auditory and Visual Strategies to Improve Accessibility
Office accessibility. Given that a number of older patients with dual sensory loss will seek hearing and balance services, it is important that a hearing care practice be physically accessible. Although this may require an initial monetary investment, such accommodations will likely result in patients reporting greater customer satisfaction with hearing health care services. The positive “word of mouth” marketing that will be the outcome of the physical accessibility of the practice will offset the initial investment, especially as older adults are the primary users of hearing aids and are an untapped market for hearing care services.
Vision assistive devices. Low-vision assistive technology that is helpful for patients with vision loss include hand held magnifiers, lamps with magnification, portable readers, handheld telescopes, and closed circuit television (CCTV).17 These assistive vision devices can help patients see controls of amplification devices. In addition, auditory rehabilitation education materials can be magnified. It is also recommended that video materials available for patients be captioned to maximize auditory and visual information.
By having several of these vision devices available in the hearing care practice for demonstration, the older adult with vision loss becomes more confident in learning about hearing aid technology and is more likely to use the devices independently and successfully.
Lighting. Lighting is crucial in testing and counseling areas. Whenever possible, dimmers should be used as well as incandescent lighting. Lighting issues for those with vision loss may include sensitivity to glare and light, color discrimination, and reduced contrast sensitivity.
Furniture should be placed strategically with ample space for navigation with a cane or a guide dog. Office support staff ought to orient the patient with dual sensory loss to the physical space. In addition, providing the patient with detailed verbal instructions throughout the session is very beneficial and reduces the patient’s anxiety.
Printed materials. Forms—case history, contracts, education materials, hearing handicap scales, and communication scales— should be printed in fonts of size 14 or larger. Printed materials should have good contrast, with black print on a white background of non-glossy paper as the preferred choice to maximize contrast sensitivity. If the hearing care practice is providing services to individuals who are legally blind, then Braille materials should be available.
Understanding the extent of vision loss. According to Kricos,7 time will be better managed if information, such as the case history intake, is sent out in advance of the hearing or balance evaluation. It also may be helpful to ask the patient to provide reports from vision specialists so that the hearing care provider is informed about the extent of vision loss. At the time of the evaluation, a quick vision screening can be performed by using the Snellen chart to obtain information on visual acuity status. The Pelli-Robinson chart can be used to assess low contrast vision required for reading printed materials and for seeing fine details required for speechreading.
Ensuring overall vision/hearing access. Every hearing care practice should have assistive listening devices available for use during case history intake and counseling sessions, especially when dealing with a patient who has a moderate or greater degree of hearing loss. The use of these devices increases conversational fluency, demonstrates the technology available, and illustrates communication benefits.
Frequent verbal and physical interaction with the patient during the test session is important. It may be wise to use an audiology assistant or ask a family member to remain in the test booth to make the patient more comfortable during the evaluation.
If the hearing care practice has a professional Web site, then steps can be taken to maximize its accessibility for those with vision loss. Features of an accessible Web site include the ability to change the font size, ample spacing between the letters and words, best color for contrast sensitivity, and good visibility of images. Every image should be accompanied by text descriptions in the event that a patient accesses the Web site using speech synthesis software.
Enlisting help from a vision specialist. It is beneficial to ask a vision specialist to visit the Web site and hearing care practice to provide feedback about its accessibility to patients with significant vision loss. In exchange, you may offer your assistance in making their practice more hearing accessible.
ADDITIONAL ONLINE RESOURCE:
Each patient with dual sensory loss should have an individual audiologic rehabilitation plan that involves both hearing and vision professionals working in tandem so that the most appropriate assistive technology and rehabilitation will be recommended.
At this time, there is limited research on dual sensory loss in the elderly population. Some possible topics for future research include:
• Best practice models for auditory rehabilitation with this population;
• Effective educational models for vision, hearing professionals, and consumers; and
• The role of preventative medicine in reducing the incidence of dual sensory loss.
Such research information will allow the hearing care provider to offer the most effective services to improve the quality of life for individuals with dual sensory impairments and their families.