February 06, 2018
5 min read

Interventions increase diabetic retinopathy screenings, but not all patients see their importance

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Interventions geared towards the health care system, health care professionals, and patients led to a 12% increase in retinopathy screening attendance vs. usual care, according to a recently published Cochrane Systematic Review.

“Due to the prevalence of diabetic retinopathy and the very real risk it poses to sight, our review highlights the importance of such interventions, as similar increases in attendance could have significant implications for people with diabetes, as the earlier we can detect the signs of retinopathy, the sooner we can start treatment,” John Lawrenson, PhD MSc, an author of the Cochrane review and professor of clinical visual science at City University of London, said in a press release.

According to the release from the City University London, about 93 million people worldwide may have some form of diabetic retinopathy, with 28 million of those people at the endpoint of the disease, which can lead to loss of sight.

The review’s authors found that effective provider-focused interventions included clinician education and audit and performance feedback; on the system level, using telemedicine, creating electronic registrations and recall and making staff changes when appropriate, were most beneficial to increasing the number of screenings.

Lawrenson and colleagues also found that successful patient interventions included utilizing reminders and providing educational programs that bolster awareness of diabetic retinopathy and elevate self-management.

Previous data suggest not all patients realize the long-term threat of diabetic retinopathy, and since the disease is often asymptomatic, early detection and such interventions are critical.  CDC data suggest as many as 50% of patients are not getting appropriate eye exams, or are delaying diagnosis and then finding out too late they have diabetic retinopathy for treatments to be effective. A 2016 survey by the American Optometric Association (AOA), found 79% of Americans are unaware that diabetic eye disease begins before there are visual symptoms.

In an earlier interview with Healio Family Medicine, a leading retina specialist said that as the health care provider with the most experience with a patient’s overall health, PCPs can play a critical role in preserving vision by fostering better glycemic control and by encouraging annual eye exams.

“Primary care doctors are the front line of care between a diabetic patient and eye physician. They’re the people that see the patients on an annual basis and really have a good sense of how they’re doing from a systemic state,” Rishi P. Singh, MD, of the Cleveland Clinic Cole Eye Institute, and associate professor of ophthalmology at Case Western Reserve University, Cleveland, told Healio Family Medicine. “So those patients who are well controlled on their diabetes will manifest less symptoms, yet everyone should get dilated eye examinations. It’s really an important thing for them to be able to understand the ramifications of late referral but also understand that there are treatments available for even the earliest forms of the disease.” 

“Primary care doctors recognize [how early the damage can set in], but the problem from that standpoint is they’re managing the entire patient - the eyes are only part of the patient they’re managing,” he said. “It becomes very complicated because they don’t have formal eye assessments of how patients are doing … They can only ask questions about a patient’s diabetic eye state and about symptoms and signs, and see what the patient elicits to determine if a referral is needed.”

Singh added the lines of communication must remain open between patients and all their medical specialists.

“Diabetologists, endocrinologists, and primary care physicians comprise a group of people critical to interacting and referring patients to ophthalmologists and vice versa,” he said. “We’d love to provide data back to them on how their patients are doing. It’s really a concerted approach. I think benefits are achieved most times people work together on this.”

For patients at highest risk for developing retinopathy, the clinician’s role is even more important in explaining the risk for vision loss.

Higher systolic blood pressure, insulin use, longer timespan for having diabetes, higher hemoglobin A1c levels and being male have also been independently connected to diabetic retinopathy occurrence. The CDC says the most advanced form of diabetic retinopathy is almost three times as common in blacks and more than twice as common in Mexican-Americans than in whites.

Screening guidelines

The American Diabetes Association (ADA) screening guidelines state adults with type 1 diabetes should have their first comprehensive, dilated eye exam within 5 years after the onset of diabetes; for patients with type 2 diabetes, the exam should take place at the time a patient is diagnosed. The timeline for future eye exams can be extended to 2 years if no signs of retinopathy are found in one more eye exams. The ADA also recommends patients get an eye exam before pregnancy or in the first three months of it. These patients should then be monitored every trimester and for 1 year postpartum as indicated by the level of retinopathy.

In addition, the ADA recommends patients with diabetes experiencing the following conditions should be directed to an eye care professional:

  • change in side vision;
  • straight lines do not look straight;
  • spots or floaters;
  • pressure in the eyes;
  • red eyes that don’t go away;
  • ·one or both of their eyes hurt;
  • double vision; and
  • difficulty reading

Diabetic retinopathy diagnosis

Diabetic retinopathy results in damage to blood vessels in at least one eye, usually both; this damage begins before vision is impaired. As the disease progresses to the proliferative form, new blood vessels form and rupture, causing blood to leak into the vitreous, obscuring vision. 

According to the American Academy of Ophthalmology (AAO) website, the only way to detect the disease is through a comprehensive eye exam that includes a visual acuity test, slit-lamp exam and dilated eye exam. Retinal photography is the only definitive screening tool for diabetic retinopathy. In some instances, ultrasound or fluorescein angiography may also be required.

“Having your regular doctor look at your eyes is not enough. Nor is having your eyeglass prescription tested by an optician. Only optometrists and ophthalmologists can detect the signs of retinopathy. Only ophthalmologists can treat retinopathy,” according to the ADA website, while the AOA warns online vision apps only check for refractive errors and are not suitable for detecting diabetes.

Treatment options

ADA guidelines state to “promptly refer patients with any level of macular edema, severe nonproliferative diabetic retinopathy (a precursor of proliferative diabetic retinopathy), or any proliferative diabetic retinopathy to an ophthalmologist who is knowledgeable and experienced in the management and treatment of diabetic retinopathy.”

The most common treatment for diabetic retinopathy anti-VEGF agents such as Eylea (aflibercept, Regeneron), Avastin (bevacizumab, Genentech) and Lucentis (ranibizumab, Genentech), which are injected monthly when the disease is detected, but in most cases, after the disease progression is under control, can be reduced in frequency. For some patients who have lost vision, anti-VEGF treatments have been shown to improve visual acuity.

If anti-VEGF agents are ineffective, vitrectomy or scanning laser photocoagulation can limit the extent of vision loss.

“Even nowadays with the worst of damage, the surgical techniques are improving, the drugs have gotten a lot better,” Singh said. “You definitely have a lot of ways to treat these patients, so it’s a matter of making sure [the patient] gets to a qualified retina specialist that knows how to take care of these issues.”  by Janel Miller

Further reading:

https://nei.nih.gov/health/diabetic/retinopathy (accessed 11-23-16)

http://www.cdc.gov/visionhealth/risk/age.htm (accessed 11-23-16)

https://www.aao.org/eye-health/diseases/diabetic-retinopathy-diagnosis (accessed 11-23-16)

http://professional.diabetes.org/CONTENT/CLINICAL-PRACTICE-RECOMMENDATIONS%20 (accessed 11-15-16)

http://aoa.uberflip.com/i/578152-aoa-clinical-practice-guidelines-adult-eye-exam (accessed 11-15-16)

Disclosure: Singh reports receiving consulting fees and research funding for Alcon, Regeneron and Genentech. He also reports receiving consulting fees for Shire, Zeiss and Optos.