Low vision is a chronic condition affecting one in six adults over 45 years of age. An estimated 14 million people in the United States suffer from low vision according to the National Eye Institute, with approximately 135 million worldwide. Visual impairment is included among the 10 most prevalent causes of disability in America and is the third leading cause of disability in older adults. The Low Vision Concepts program at Saint John Hospital in Leavenworth, Kan., helps patients with personalized goals to maximize their ability to perform desired tasks.
According to Dixie Anaya, Saint John Occupational Therapist, low vision impairments affect both independence in the performance of daily activities and safety in the environment. “Such impairments are a primary contributor to falls which result in further injury,” she said. “People with low vision can also suffer from decreased self-esteem, lowered personal productivity and an all-around less satisfying life. Our occupational therapists train patients in ways to use the vision they still have and instruct them in alternative methods to
continue daily living skills. As a result, individuals can lead a more fulfilling life.”
Patients experiencing difficulty with their vision for any of the following activities may seek assistance from the Low Vision Concepts program: reading bills, writing letters, completing a checkbook ledger, telling time, cooking, identifying money, recognizing faces or stepping on/off stairs. An appointment for evaluation and treatment can be made with an order from an ophthalmologist, optometrist or physician.
Anaya works with patients referred to the Low Vision Concepts program by ophthalmologists and other physicians. “The more common causes of low vision include macular degeneration, diabetic retinopathy, glaucoma and vision deficits, which can occur with stroke or brain injury,” she said. “Cataracts are also a leading cause of visual impairment, but can generally be corrected surgically.”
“Macular degeneration affects the part of the eye responsible for central vision and color vision,” Anaya explained. “It generally causes a gray or blank spot in the center of the visual field which can make it difficult to do such tasks as read, write, dial a telephone, use a hammer or see faces clearly.”
She also explained that diabetic retinopathy is caused by the blood vessels of the eye leaking or growing abnormally, causing scattered ‘blind spots’. “Vision is blurry and can vary from day to day depending on blood glucose levels,” she said. “This fluctuating vision can also interfere with a wide range of everyday activities including reading, writing, telling time, and moving about safely. People with retinopathy can also have difficulty with giving themselves insulin shots which is necessary for controlling their diabetes.”
Glaucoma is caused by a build up of fluid in the eye that creates increased pressure. Tunnel vision occurs, affecting side vision and results in difficulty seeing objects to the sides, near the head, or by the feet making
safety a real concern. Anaya said that glaucoma also causes difficulty with functioning in low light, limits contrast sensitivity, and affects tolerance for glare in the environment.
Visual loss from neurological conditions primarily affects the visual field. One half of the visual field may appear to be missing due to injury to either the optic nerve or brain. This impairment, like the others, also affects mobility in the environment, as well reading, writing, cooking, eating and most other daily living skills.
Using optical and non-optical devices
Despite the many limitations experienced by patients with low vision, many people are able to lead more independent lives with help from the Low Vision Concepts program. Methods may involve training in the use of either optical or non-optical devices. “Many non-optical devices are available which help the person to do things they haven't been able to do easily in some time,” Anaya said. “One example is the application of tactile markings to appliances such as microwaves, ovens and washers and dryers. This allows patients to use their sense of touch to locate the needed settings to operate the equipment.”
Another example is the use of liquid indicators, which when placed in a cup or bowl, alerts the person when the container is just about full by making a sound or playing a tune. Other examples of such devices include talking watches, large print checks and check registers, needle threaders and slicing guides.
Optical devices include hand held magnifiers as well as stand magnifiers which are placed directly on the reading material. Both are available with or without lighting elements.
Telescopes can be used for distance viewing, television viewing and spotting street signs.
Video magnifiers or closed circuit television units (CCTVs) are also available which provide magnification on a television like screen. These can be used for both reading and writing and can magnify an image up to 70 times its original size. As a general rule, such device recommendations are made by the ophthalmologist or optometrist with follow up training in the use of the devices by the therapist during functional activities.
Using what you have
In addition to training in the use of both optical and non-optical devices, the Low Vision Concepts program offers education in optimal use of the patient’s remaining vision. Activities such as scanning and fixation techniques and eccentric viewing are used.
“Eccentric viewing techniques are used primarily for persons who have macular degeneration,” Anaya said. “It involves teaching patients to use available areas of vision which are next to the scotoma, or ‘blank’ area of the eye, to perform functional viewing tasks.” Instruction in the various exercises is done during therapy sessions with provision of home exercises as needed.
The Low Vision Concepts program also provides instruction in low vision principles such as the use of contrast, organization and lighting to improve the person’s functional ability and safety in the environment. Resource information is also provided which may include information regarding various vendors for devices; reading materials, both audio and large print, and outreach programs such as orientation and mobility services or social services.
The program is primarily provided on a one-to-one basis, but may also involve home or work-site visits as needed. Family is welcome to attend sessions in an effort to help reinforce carry over into the home environment.