An emerging body of diabetes, vision, and health care research indicates that significant disparities in the quality and equity of eye care exist throughout the United States, more specifically within the African American and Latino patient communities.
This research includes an evaluation of the disparities in screening rates for diabetic retinopathy among minority patients, an examination of the rates of vision loss of African-American patients with diabetes, and the Los Angeles Latino Eye Study, which examined macular degeneration and related quality of life.
Most recently, The National Academies of Sciences, Engineering, and Medicine (NASEM) released a comprehensive and powerful report that proposes an all-encompassing framework “to guide action and coordination among various—and sometimes competing—stakeholders in pursuit of improved eye and vision health and health equity in the United States.”
Now, new diabetes and diabetic retinopathy research from the University of Alabama at Birmingham and Wills Eye Hospital in Philadelphia has added to this growing body of knowledge. According to the researchers, “The public health success of diabetic retinopathy screening programs depends on patients’ adherence to the timetable of follow-up eye care. African-Americans are among those at highest risk for diabetic retinopathy and have one of the lowest rates of eye care use.“
The Research from JAMA Ophthalmology
The research, entitled Patients’ Adherence to Recommended Follow-up Eye Care after Diabetic Retinopathy Screening in a Publicly Funded County Clinic and Factors Associated with Follow-up Eye Care Use, has been published “online first” in the September 15, 2016 edition of JAMA Ophthalmology, an international peer-reviewed journal published monthly by the American Medical Association.
The authors are Zachary Keenum, BS; Gerald McGwin Jr., PhD; C. Douglas Witherspoon, MD; Julia A. Haller, MD; Mark E. Clark; and Cynthia Owsley, PhD, who represent the University of Alabama at Birmingham and Wills Eye Hospital, Philadelphia, Pennsylvania.
About the Research
The prevalence of type 1 and type 2 diabetes in the United States is 9.3 percent and expected to increase, along with complications associated with diabetes that include diabetic retinopathy (DR), the leading cause of new cases of blindness among adults ages 20 to 74 in the United States. Yet many patients do not adhere to their physicians’ eye care recommendations.
[Researchers at the] University of Alabama at Birmingham … are trying to find answers to the extent county clinic patients with diabetes in a DR screening program adhere to the timetable of recommended follow-up eye examinations.
African-Americans are at higher risk for the ocular complications of diabetes than are other segments of the population. Some research has suggested that the quality of their medical care for diabetes is lower than for other groups. African-Americans’ lower rates of eye care are believed to stem from less access and more barriers to care, fewer eye care providers with practices situated in their communities, and a lack of awareness of their high-risk status for vision loss and how routine preventive care could reduce that risk.
For the study, screenings were performed at Cooper Green Mercy Health Services’ internal medicine clinic in Birmingham. Data from the Jefferson County Health System’s administrative database pertaining to eye care utilization for the patients screened were obtained from January 2012 through May 2015.
When the follow-up eye care utilization data were examined, only 29.9 percent of patients adhered to recommendations to have an eye examination within indicated time frames, even though cost and accessibility were minimized as barriers. Two years after the initial screening, 50.9 percent still had not undergone an eye examination.
[Study co-author] Dr. Cynthia Owsley says strategies for developing and implementing effective education at DR screenings should be carried out as next steps. “The education would focus on communicating the importance of seeking the eye care that is recommended following the screening, and also on communicating how to avoid barriers to care.”
More about Diabetic Eye Disease
Although people with diabetes are more likely to develop cataracts at a younger age and are twice as likely to develop glaucoma as people who do not have diabetes, the primary vision problem caused by diabetes is diabetic retinopathy, the leading cause of new cases of blindness and low vision in adults aged 20-65:
- “Retinopathy” is a general term that describes damage to the retina.
- The retina is a thin, light-sensitive tissue that lines the inside surface of the eye. Nerve cells in the retina convert incoming light into electrical impulses. These electrical impulses are carried by the optic nerve to the brain, which interprets them as visual images.
- Diabetic retinopathy occurs when there is damage to the small blood vessels that nourish tissue and nerve cells in the retina.
- “Proliferative” is a general term that means to grow or increase at a rapid rate by producing new tissue or cells. When the term “proliferative” is used in relation to diabetic retinopathy, it describes the growth, or proliferation, of abnormal new blood vessels in the retina. “Non-proliferative” indicates that this process is not yet occurring.
- Proliferative diabetic retinopathy affects approximately 1 in 20 individuals with the disease.
Four Stages of Diabetic Retinopathy
According to the National Eye Institute, diabetic retinopathy has four stages:
- Mild non-proliferative retinopathy: At this early stage, small areas of balloon-like swelling occur in the retina’s tiny blood vessels.
- Moderate non-proliferative retinopathy: As the disease progresses, some blood vessels that nourish the retina become blocked.
- Severe non-proliferative retinopathy: Many more blood vessels become blocked, which disrupts the blood supply that nourishes the retina. The damaged retina then signals the body to produce new blood vessels.
- Proliferative retinopathy: At this advanced stage, signals sent by the retina trigger the development of new blood vessels that grow (or proliferate) in the retina and the vitreous, which is a transparent gel that fills the interior of the eye. Because these new blood vessels are abnormal, they can rupture and bleed, causing hemorrhages in the retina or vitreous. Scar tissue can develop and can tug at the retina, causing further damage or even retinal detachment.
What Is a Vision Screening?
A vision screening is a relatively short examination that can indicate the presence of a vision problem, such as diabetic retinopathy, or a potential vision problem. A vision screening cannot diagnose exactly what is wrong with your eyes; instead, it can indicate that you should make an appointment with an ophthalmologist or optometrist for a more comprehensive dilated eye examination.
What Is a Comprehensive Dilated Eye Examination?
A comprehensive dilated eye examination generally lasts between 30 and 60 minutes, and is performed by an ophthalmologist or optometrist. It should include the following components:
A Health and Medication History
- Your overall health and that of your immediate family
- The medications you are taking (both prescription and over-the-counter)
- Questions about high blood pressure (hypertension), diabetes, smoking, and sun exposure.
A Vision History
- How well you can see at present, including any recent changes in your vision
- Eye diseases that you or your family members have had, including macular degeneration and glaucoma
- Previous eye treatments, surgeries, or injuries
- The date of your last eye examination
An Eye Health Evaluation
- An examination of the external parts of your eyes: the whites of the eyes, the iris, pupil, eyelids, and eyelashes.
- A dilated internal eye examination: Special eye drops will dilate, or open, your pupil, which allows the doctor to observe the inner parts of your eye, such as the retina and optic nerve. This can help to detect subtle changes of the optic nerve in persons without any visual symptoms and potentially lead to early detection of disease, including diabetic retinopathy.
- A test of the fluid pressure within your eyes to check for the possibility of glaucoma.
A Refraction, or Visual Acuity Testing
A refraction helps determine the sharpness or clarity of both your near (reading) and distance vision.
This includes testing your vision with different lenses (sometimes contained in a machine called a phoropter, pictured at right) to determine if your vision can be improved or corrected with regular glasses or contact lenses.
Visual Field Testing
Visual field testing helps determine how much side (or peripheral) vision you have and how much surrounding area you can see.
The most common type of visual field test in a comprehensive eye exam is called a confrontation field test, in which the doctor briefly flashes several fingers in each of the four quadrants (above, below, right, and left) of your visual field while seated opposite you.
In some cases, your doctor may also want to perform a more precise visual field measurement, using a computerized visual field analyzer, such as the Humphrey Field Analyzer (pictured at left).
Your Examination Results
The doctor will be able to determine if the visual problems you are experiencing are normal age-related changes or are disease-related, and if additional testing, referral to another doctor or specialist, or treatments are needed.
More about the Study from JAMA Ophthalmology
Excerpted from the study abstract:
Importance: The public health success of diabetic retinopathy (DR) screening programs depends on patients’ adherence to the timetable of follow-up eye care recommended by the screening program. African Americans are among those at highest risk for DR and have one of the lowest rates of eye care use.
Objectives: To assess the rate of adhering to recommended follow-up eye care in a DR screening program administered in a safety-net health care facility and to examine factors associated with follow-up eye care use.
[Editor’s note: The “health care safety net” is a term that defines the array of clinical sites that provide health care opportunities for those who otherwise would have barriers to accessing quality health services. These barriers include lack of coverage, geographic isolation, language and culture, mental illness, and homelessness.]
Design, Setting, and Participants: Prospective follow-up study of persons with type 1 or type 2 diabetes. The setting was an internal medicine clinic of a publicly funded health system in Alabama, serving a population that was largely uninsured and African American, that had implemented a DR screening program using a non-mydriatic camera for ocular imaging and remote reading centers for evaluation of images.
[Editor’s note: A prospective study measures a group of individuals over time and follows up with the study subjects in the future. A non-mydriatic camera is one that will take a picture of the retina, without the need for bright lighting and eye drops that dilate, or open up, the pupil. This can make the exam proceed more quickly by eliminating wait times for (a) the pupil to dilate and (b) the eye to adjust following the light flash that accompanies the retinal photo.]
Patients with physician appointments between January 26 and July 24, 2012, were eligible for screening if they had a diagnosis of type 1 or type 2 diabetes and were 19 years or older. Data from the county health system’s administrative database were obtained from January 26, 2012 (date of first enrollee), through May 1, 2015, to establish participants’ eye care use in the ophthalmology clinic after screening.
Results: Diabetic retinopathy screening was completed in 949 adults with diabetes, of whom 84.5% were African American, 64.5% were women, and 71.7% lacked health insurance. Participants ranged in age from 21 to 95 years, and their mean age was 53.9 years. The mean age at diabetes diagnosis was 44.3 years, and the mean duration of diabetes was 9.6 years. 29.9% adhered to obtaining comprehensive follow-up eye care within the recommended time frame.
Two years after a participant’s screening date, 50.9% had no record of having received eye care. Factors associated with adhering to interval appointments were having an advanced age and knowing one’s glycated hemoglobin level. Agreeing to assistance in making a follow-up eye care appointment was associated with nonadherence.
[Editor’s note: The glycated hemoglobin test, also known as the A1c blood test, hemoglobin A1c, and HbA1c, is the primary tool used to diagnose diabetes and pre-diabetes and to monitor blood glucose control in people with type 1 and type 2 diabetes. This test enables health care providers to diagnose diabetes and treat it before complications occur and to diagnose pre-diabetes to prevent or delay the development of type 2 diabetes. You can read more about the established A1c levels used to diagnose diabetes and pre-diabetes at Diabetes and the Significance of the A1c Test on the VisionAware blog.]
Conclusions and Relevance: After a DR screening program in a public clinic largely serving an African American population, only one-third of participants adhered to interval recommendations for follow-up eye appointments, even though cost and accessibility were minimized as barriers to care. Our findings suggest that DR screening programs are not likely to meet their public health goals without incorporation of eye health education initiatives successfully promoting adherence to recommended comprehensive eye care for preventing vision loss.