New Research: Significant Disparities Exist in Screening Rates for Diabetic Retinopathy among Minority Patients

retina with diabetic retinopathy

New diabetes research from the University of California at Los Angeles indicates that there is a pronounced disparity in diabetic retinopathy screening rates between Hispanic and African American patients.

Compared with Hispanic patients, African American patients were screened 50% less often in the previous year, despite reporting similar barriers to screening, similar awareness that diabetes may lead to diabetic retinopathy, and the same likelihood of receiving physician recommendation for diabetic retinopathy screening.

“Our findings of a large discrepancy in diabetic retinopathy screening rates among safety-net minority communities may have important implications for consequent risk of blindness,” the researchers wrote. “Different approaches to encourage diabetic retinopathy screening may be necessary in different minority populations.”

From Diabetes Care

The research, entitled Disparities in Diabetic Retinopathy Screening Rates within Minority Populations: Differences in Reported Screening Rates among African American and Hispanic Patients, has been published online ahead-of-print in the December 30, 2015 edition of Diabetes Care, a peer-reviewed journal published monthly by the American Diabetes Association (ADA). Diabetes Care is a journal for health care practitioners that is intended to increase knowledge, stimulate research, and promote better management of people with diabetes.

The authors are Yang Lu, Lilian Serpas, Pauline Genter, Christina Mehranbod, David Campa, and Eli Ipp, who represent the following institutions: the Los Angeles Biomedical Research Institute, St. Torrance, CA; the David Geffen School of Medicine, University of California, Los Angeles; and the Los Angeles County Department of Health Services.

About the Research

Excerpted from Screening for Diabetic Retinopathy Varies Among Minorities, via Endocrinology Advisor:

For patients with diabetes, diabetic retinopathy screening varies for different minority groups, according to research published in Diabetes Care.

Yang Lu, PhD, from Los Angeles Biomedical Research Institute in St. Torrance, California, and colleagues examined perceived barriers to diabetic retinopathy screening in vulnerable populations using survey data collected from 101 patients with diabetes, including 71 Hispanics and 27 African-Americans.

The researchers found that most patients were aware of diabetic retinopathy as a potential complication of diabetes, and more than 75% reported that a physician had recommended diabetic retinopathy screening. However, only 55% reported screening in the previous year.

African-American patients were screened 50% less often than Hispanic patients in the previous year (30.4% vs 62.7%); this was in spite of [both groups] reporting a similar number of barriers to screening (1.6 each), similar awareness that diabetes may lead to diabetic retinopathy (100% vs 90%), and similar likelihood of receiving a screening recommendation [from a physician] (78% vs 77%).

More about the Research from Diabetic Care

From the article introduction:

Diabetic retinopathy screening is essential for early detection and treatment of diabetes-related visual impairment and blindness. Yet, it is commonly underutilized among low-income minority patients. To examine perceived barriers to diabetic retinopathy screening in these vulnerable populations, we collected survey data from 101 patients with diabetes, including 71 Hispanics and 27 African Americans at a large safety-net clinic in South Los Angeles.

[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.]

Patients surveyed demonstrated typical characteristics for a safety-net population. Among patients surveyed, 50% reported less than $10,000 in annual household income, 56% were unemployed, and 33% had a high school diploma/GED or above.

The survey revealed that most patients were aware of diabetic retinopathy as a potential complication of diabetes and more than 75% acknowledged that a physician had recommended diabetic retinopathy screening, yet only 55% reported screening in the previous year, similar to previously reported rates in underserved populations.

However, compared with Hispanic patients, African American patients were screened 50% less often in the previous year (30.4 vs 62.7%), despite reporting a similar total number of barriers to screening (1.6 each), similar awareness that diabetes may lead to diabetic retinopathy (100% vs 90%), and the same likelihood of receiving physician recommendation for diabetic retinopathy screening (78% vs 77%).

Patients in each population also reported similar types of barriers to diabetic retinopathy screening. The exceptions were that more Hispanic patients felt that being “upset” or “depressed” was a barrier, and more African American patients reported “fear of screening” or “not being comfortable …”

About Diabetic Eye Disease

Diabetic Retinopathy

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:

NEI example of seeing with diabetic retinopathy: many blind spots and overall blurriness
What a person with diabetic retinopathy sees
  • “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.

Diabetic Macular Edema

Diabetic macular edema [edema = a swelling or accumulation of fluid] (DME) can occur in people with diabetes when retinal blood vessels begin to leak into the macula, the part of the eye responsible for detailed central vision. These leakages cause the macula to thicken and swell, which, in turn, creates a progressive distortion of central vision.

Although this swelling does not always lead to severe vision loss or blindness, it can cause a significant loss of central, or detail, vision, and is the primary cause of vision loss in people with diabetic retinopathy. DME can occur at any stage of diabetic retinopathy, but it is more likely to occur as the disease progresses.

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 phoropter

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.

Humphrey Field Analyzer

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.

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Additional Diabetes Information