Early detection and treatment of DR and DME are essential

Early fundus findings of DR include microaneurysms, intraretinal hemorrhages, cotton wool spots, and exudation. (Adobe Stock image)

Retina experts Rishi P. Singh, MD, and Carolyn Majcher, OD, FAAO, participated in a Modern Retina/Ophthalmology Times Insights video filming recently to discuss some of the challenges in managing diabetic retinopathy (DR) and diabetic macular edema (DME).

Singh is a staff physician and president of Cleveland Clinic Florida, Martin Health, in Stuart. Majcher is an associate professor and director of residency programs at Northeastern State University Oklahoma College of Optometry in Tahlequah.

The importance of sharing tips between ophthalmology and optometry practices is underscored by the data: approximately 7% to 8% of the population in the United States has diabetes, and by 2045, 15% of the population is expected to be diabetic, Singh warned.

These data, Majcher said, foretell the future of increasing eye care demands. Vision-threatening retinopathy complications, especially DME, will become more prevalent as the leading causes of vision loss.

Singh pointed out that the biggest outcome predictor is a patient’s baseline visual acuity (VA). It is vital to educate patients that earlier evaluation and treatment will lead to a better VA prognosis, he noted.

dilated eye examinations

Majcher advised that patients with type 1 diabetes should have annual DR screenings beginning 5 years after disease onset. Patients with type 2 diabetes require prompt examinations at diagnosis and every year thereafter. These patients likely had diabetes even before they received their diagnosis.

She also said pregnant women with diabetes should be examined early in the pregnancy to identify retinopathy development/progression.

In those without DME, mild nonproliferative DR (NPDR) can be monitored yearly, and moderate NPDR can be monitored every 6 to 9 months. With center-involved DME, follow-up should be every 3 to 6 months. Severe NPDR without DME needs a referral and monitoring every 3 months, she said.

Diagnosis and staging

Vision-threatening complications may be present despite 20/20 VA in patients who are unaware that they have type 2 diabetes. They may present with myopic shift or retinopathy during a routine examination, gradual painless visual declines bilaterally or fluctuating vision, acute-onset monocular vision loss, increased floaters from vitreous/preretinal hemorrhages, or macular ischemia. The most common cause of vision loss is DME, which occurs at any DR stage, Majcher said.

Early fundus findings of DR include microaneurysms, intraretinal hemorrhages, cotton wool spots, and exudation. More severe stages of NPDR include intraretinal microvascular abnormalities, venous feeding, and vessel sheathing in severe retinal nonperfusion and ischemia. Proliferative diabetic retinopathy (PDR) features include preretinal neovascularization and vitreous or preretinal hemorrhages. PDR findings that include poor fixators, media opacity, significant photophobia, and a deceptively quiet fundus with minimal to no DR signs make staging challenging, Majcher explained.

Another hurdle is identifying patients who may progress rapidly because of long-standing disease, poor glycemic control, comorbidities, or nonadherence. Singh said patients with the highest progression risk are those with severe NPDR that will likely become proliferative within 1 to 2 years.

Majcher believes multimodal imaging technologies, optical coherence tomography (OCT), OCT angiography (OCTA), and fluorescein angiography facilitate accurate staging and early PDR detection. Widefield and ultra-widefield imaging devices image approximately 80% of the retinal surface, capturing peripheral retinal hemorrhaging that is at greater risk of progression to proliferation.

OCT provides high-resolution, cross-sectional images of retinal layers and is most useful for detecting/classifying macular edema (ME). OCTA provides high-resolution microvascular details that highlight subtle/invisible vascular abnormalities during clinical fundus examinations alone.

Optometry:
The health care gateway

The American Optometric Association (AOA) 2019 clinical practice guidelines advise that patients with PDR, ME, or severe NPDR without ME be referred to a retina specialist within 2 to 4 weeks. The AOA also recommends referral in 24 to 48 hours for those at high risk of proliferation. Mild to moderate NPDR is typically referred when ME is present.

Majcher advised referral with uncertain disease stages and prompt referral for anterior segment neovascularization. She advises optometrists to follow up with patients to ensure they were examined by a retina specialist in light of financial barriers, reliance on others for transport, and patient comorbidities.

Treatment options

Anti–vascular endothelial growth factor (VEGF) therapy can prevent neovascular glaucoma and tube-shunt surgery, Majcher said. Anti-VEGF therapies also provide the best outcomes and safety profiles, according to Singh.

Steroids and laser photocoagulation are the second- and third-line options, respectively, for NPDR and DME. Proliferative disease requires panretinal laser to treat the entire retina.

Singh believes anti-VEGF treatments may be underutilized options for DME. They do not have the adverse effects of steroids and photocoagulation, and retreatment intervals can extend 2 to 3 months.

Faricimab (Vabysmo; Genentech), a recently approved combination of an angiopoietin-2 inhibitor and anti-VEGF drug for DME, provides good results and lower treatment burdens. Approximately 75% to 78% of patients have treatment intervals of every 12 weeks or beyond at 2 years after receiving those drugs. The 8-mg dose of aflibercept (Eylea; Regeneron Pharmaceuticals, Inc), an investigational product that Singh is anticipating, offers an improved treatment burden vs the 2-mg dose.

The Future

Tyrosine kinase inhibitors are being studied in age-related macular degeneration and can easily be transitioned to the DME population, Singh noted. This technology should also increase the treatment intervals.

Photobiomodulation, a light-based therapy, is being tested and improved in Europe for DR and DME. Pan-VEGF inhibition also may help control patients’ disease and reduce fluid over time.

Singh said home OCT will be a future technology that will decrease office visits, monitor severe distortion, and transfer images to the office. Other potential innovations are intraoperative surgical maneuvers that can assist outcomes for patients.

“It is exciting to see all this coming together,” he said. •