with low vision
New research from Johns Hopkins University School of Medicine reveals that the annual number of new cases of blindness and low vision among people aged 45 years and older is estimated to double during the next 30 years.
Because data about the incidence of blindness and low vision in the United States was formally estimated more than a decade ago, using United States Census data from 2000, the study authors emphasize that more current and detailed estimates are needed to inform policy makers to meet the current and growing demands for low vision rehabilitation services.
According to lead author Tiffany Chan, OD, “These updated results may help policymakers plan for the future and decide how to allocate resources to help people with loss of vision, an often life-changing issue. We expect a greater need for services for those patients with low vision as the aging population increases over the next several decades.”
From JAMA Ophthalmology
This important new research, titled Estimates of Incidence and Prevalence of Visual Impairment, Low Vision, and Blindness in the United States has been published online as an open-source article in the November 2, 2017 edition of JAMA Ophthalmology. JAMA Ophthalmology is an international peer-reviewed journal published monthly by the American Medical Association.
The authors are Tiffany Chan, OD; David S. Friedman, MD, MPH; Chris Bradley, PhD; and Robert Massof, PhD, from The Lions Vision Research and Rehabilitation Center and the Wilmer Eye Institute at Johns Hopkins University School of Medicine, Baltimore, Maryland. You can read more about Dr. Massof’s low vision work at Meet Dr. Robert Massof from Johns Hopkins University: Innovator, Visionary, Pioneering Low Vision Researcher, and Visionize Collaborator on the VisionAware website.
First, An Explanation of Terms Used in the Research
Here is a brief explanation of two key terms used in this low vision research:
- Prevalence: the number of cases of a disease or disorder—in this case, low vision—that are present in a particular population at a given time, or how widespread the disease or condition is.
- Incidence: the number of new cases of a disease or disorder that develop in a given period of time.
About the Low Vision Research
Edited and excerpted from Low Vision, Blindness Expected to Double in Next 30 Years, via Medscape:
The annual number of new cases of blindness and low vision among people aged 45 years and older is estimated to double during the next 30 years, suggests a study published online November 2 in JAMA Ophthalmology.
“[A]ssuming the prevalence and mortality rates stay constant, we expect a greater need for services for those patients with [low vision] as the aging population increases over the next several decades,” said [co-author] Tiffany Chan, OD.
Most low vision and blindness are related to aging, and both contribute greatly to disability in the United States. Visual impairment can interfere with daily activities and increases the risk for falls and medication mismanagement.
Knowing the incidence, or the number of new cases of low vision each year, is important for policy makers and may be more informative than prevalence, which represents the backlog of people who still need services. However, the prevalence and incidence of blindness and low vision in the United States have not been estimated for more than a decade.
The researchers used visual acuity measurements taken from 6,016 participants in the 2007 to 2008 National Health and Nutrition Examination Survey (NHANES). Because NHANES has data on age, sex, and race/ethnicity, researchers were able to analyze the data by these variables. They also used 2010 census data and constructed rate models to estimate the annual incidence of low vision and blindness for 2017, 2030, and 2050.
[Editor’s note: The National Health and Nutrition Examination Survey, part of the National Center for Health Statistics, is a program of studies designed to assess the health and nutritional status of adults and children in the United States. The survey is unique in that it combines interviews and physical examinations.]
The investigators defined low vision as best-corrected visual acuity in the better-seeing eye of less than 20/60 (according to the World Health Organization and Medicare definitions) or less than 20/40 (according to consensus that limitations may occur at this level of acuity). They considered blindness as best-corrected visual acuity of 20/200 or less, or legal blindness as defined by the U.S. Social Security Administration.
Results suggested that both prevalence and annual incidence of low vision and legal blindness will roughly double during the next three decades among people aged 45 years and older.
In this age group, the estimated prevalence of best-corrected visual acuity less than 20/40 is estimated to increase from 3,894,406 in 2017 to 7,594,797 in 2050.
The estimated prevalence of best-corrected visual acuity less than 20/60 is expected to increase from 1,483,703 in 2017 to 2,893,490 in 2050.
The prevalence of legal blindness is estimated to increase from 1,082,790 in 2017 to 2,111,637 in 2050.
Likewise, the estimated annual incidence of best-corrected visual acuity less than 20/40 among people aged 45 years and older is expected to jump from 481,970 new cases in 2017 to 1,006,711 in 2050.
The annual incidence of best-corrected visual acuity less than 20/60 in this same age group is expected to increase from 183,618 new cases in 2017 to 383,539 in 2050.
The number of new cases of legal blindness is expected to increase from 134,002 in 2017 to 279,900 in 2050.
What Is Low Vision?
If your eye doctor tells you that your vision cannot be fully corrected with ordinary prescription glasses, medication, or surgery, but you find you still have some usable vision, you have what is called “low vision.”
Having low vision means that even with regular glasses, contact lenses, medication, or surgery, you can find it difficult to perform everyday tasks, such as reading your mail, shopping, preparing meals, and signing your name.
Low Vision Optical Devices
One way to address low vision is through the use of low vision optical devices, such as magnifiers and magnifying reading glasses and small telescopes, and electronic magnifiers and magnifying systems, including electronic desktop and portable digital magnifiers.
All of these low vision optical devices should be prescribed by an ophthalmologist or optometrist who specializes in low vision and performs a thorough and comprehensive low vision examination with you.
Low Vision Non-Optical Devices
Low vision non-optical devices can also be helpful for people who have low vision.
Low vision non-optical devices can include improved lighting and flexible-arm task lamps, reading stands, absorptive sunglasses, typoscopes, tactile locator dots, and colored acetate sheets.
These non-optical devices are often recommended as part of a comprehensive low vision examination, and you can use them in combination with magnifiers and other low vision optical devices.
Vision Rehabilitation Services for Low Vision
“Vision rehabilitation” includes a wide range of professional services that can restore functioning after vision loss, just as physical therapy restores function after a stroke or other injury. Vision rehabilitation services allow people who have recently lost vision, are blind, or have low vision to continue to live independently and maintain their accustomed quality of life.
Although your eye doctor is the professional you’ll likely turn to first when dealing with your own – or a family member’s – vision loss, it’s important to note that many different kinds of vision rehabilitation services are available in addition to the eye care provided by your family doctor, ophthalmologist, optometrist, or low vision specialist. In fact, your own doctor may not be aware of, or refer you to, these comprehensive vision rehabilitation services, which are often provided through a state or non-profit rehabilitation agency, at little or no out-of-pocket cost.
Who provides vision rehabilitation services?
Vision rehabilitation services for adults who have recently lost vision, are blind, or have low vision are provided by a team of specially trained professionals, which may include low vision therapists, vision rehabilitation therapists, and orientation and mobility specialists:
Low Vision Therapists
Certified Low Vision Therapists (CLVTs and SCLVs) instruct individuals in the efficient use of remaining vision with optical devices, non-optical devices, and assistive technology, and can help determine the need for environmental modifications in the home, workplace, or school. You can learn more about these professionals at the Low Vision Therapy website and the American Occupational Therapy Association – Low Vision website.
Vision Rehabilitation Therapists
Certified Vision Rehabilitation Therapists (CVRTs) teach adaptive independent living skills, enabling adults who are blind or have low vision to confidently carry out a range of daily activities. CVRTs work with individuals in their homes, rehabilitation facilities, and employment settings. You can learn more about these professionals at the Vision Rehabilitation Therapy website.
To learn more about what a Vision Rehabilitation Therapist does and how you could benefit, read What Is a Vision Rehabilitation Therapist?.
Orientation and Mobility Specialists
Certified Orientation and Mobility Specialists (COMS or O&Ms) teach the skills and concepts that people who are blind or have low vision need in order to travel independently and safely in the home and in the community.
O&Ms teach safe and independent indoor and outdoor travel skills, including the use of a long cane, electronic travel devices (such as GPS), public transportation, and sighted guide, human guide, and pre-cane skills. You can learn more about these professionals at the Orientation and Mobility website.
What You Can Learn with Vision Rehabilitation Lessons and Training
- Communication skills: reading and writing, braille, and assistive computer technology
- Counseling: to help you, your spouse, family members, and friends adjust to your vision loss
- Independent living and personal management skills: home modifications, home repairs, personal self-care, financial management, recreation and leisure activities, and using the telephone
- Independent movement and travel skills: moving about safely indoors, using transportation, and traveling safely outdoors with a long white cane or other device
- Low vision evaluations and training with low vision devices: the low vision examination, bioptics for driving, low vision optical devices, and non-optical devices that can make the best use of your remaining vision
- Vocational rehabilitation: Getting back to work after a vision loss, or breaking into the workplace as a job seeker with blindness or low vision, including vocational evaluation and training, job training, job modification and restructuring, and job placement.
Locating Vision Rehabilitation Services
Your state rehabilitation agency or an online searchable database can help you locate vision rehabilitation agencies in your area and find the type of services that are right for you. See State and Local Rehabilitation Agencies in the VisionAware Directory of Services to locate agencies in your area.
More About the Research from JAMA Ophthalmology
Excerpted from the article Abstract and Introduction, with the full article available online:
Low vision and blindness are leading causes of disability among U.S. residents. Updated estimates of the prevalence of blindness and low vision were recently reported using population-based studies applied to current U.S. census data.
However, the incidence of blindness and low vision in the United States was formally estimated more than a decade ago using 2000 census data. More current and detailed estimates are needed to inform policy makers to adequately meet present and growing demands for low vision rehabilitation services.
Importance: Updated estimates of the prevalence and incidence rates of low vision and blindness are needed to inform policy makers and develop plans to meet the future demands for low vision rehabilitation services.
Objective: To provide updated estimates of the incidence and prevalence of low vision and blindness in the United States.
Design, Setting, and Participants: Visual acuity measurements as a function of age from the 2007-2008 National Health and Nutrition Examination Survey, with representation of racial and ethnic groups, were used to estimate the prevalence and incidence of visual impairments. Data from 6,016 survey participants, ranging in age from younger than 18 years to older than 45 years, were obtained to estimate prevalence rates for different age groups.
Incidence and prevalence rates of low vision (best-corrected visual acuity in the better-seeing eye of less than 20/40 and less than 20/60) and blindness (best-corrected visual acuity of less than or equal to 20/200) in older adults were estimated from exponential models, fit to prevalence rates as a function of age (specified in 5-year age bins).
The prevalence and annual incidence of low vision and blindness in the United States were estimated, using the 2010 U.S. census data by age, from the rate models applied to the census projections for 2017, 2030, and 2050. Data were collected from November 1, 2007, to October 31, 2008. Data analysis took place from March 31, 2016, to March 19, 2017.
Results: Of the 6,016 people in the study, 1,714 (28.4%) were younger than 18 years of age, 2,358 (39.1%) were 18 to 44 years of age, and 1,944 (32.3%) were 45 years of age or older.
There were 2,888 male (48%) and 3,128 female (52%) participants.
The prevalence of low vision and blindness for older adults (more than or equal to 45 years) in the United States in 2017 is estimated to be:
- 3,894,406 persons with a best-corrected visual acuity less than 20/40
- 1,483,703 persons with a best-corrected visual acuity less than 20/60
- 1,082,790 persons with a best-corrected visual acuity of 20/200 or less
The estimated 2017 annual incidence (projected from 2010 census data) of low vision and blindness among older adults (more than or equal to 45 years) in the United States is:
- 481,970 persons with a best-corrected visual acuity less than 20/40
- 183,618 persons with a best-corrected visual acuity less than 20/60
- 134,002 persons with a best-corrected visual acuity of 20/200 or less
Conclusions and Relevance: Low vision and blindness affect a substantial portion of the older population in the United States. Estimates of the prevalence and annual incidence of visual impairment assist policy planners in allocating and developing resources for this life-changing loss of function.