Photo Credit: Natali_Mis
This is the second in a two-part series on treating advanced diabetic macular edema.
Diabetic macular edema (DME) treatments have dramatically evolved in recent years. Four experts in diabetic retinopathy and DME talked with Physician’s Weekly (PW) about how recent advances in treatment affect outcomes for patients with advanced DME.
PW: What approved treatments are there for advanced DME?
Dr. Coates: The primary treatment methods for advanced DME are intravitreal injections of anti-vascular endothelial growth factor (VEGF) medications. If a patient is not responding to anti-VEGF treatment, intravitreal steroid injections or focal laser photocoagulation can be considered.
Dr. Prasad: Steroids have the advantage of working on multiple inflammatory pathways that can contribute to DME. The durability of these treatments may also be longer than anti-VEGF pharmacotherapy. However, intraocular steroid benefits must be weighed against the risk of side effects, including intraocular pressure elevation and cataract progression.
Dr. Liu: There is a good correlation between decreased DME and improved vision. Patients sometimes anatomically respond better if we add a second class of medication, but often, that does not translate into better vision. Anti-VEGF medications work well for most patients, but around 10-15% of patients don’t respond well. So, for diabetic retinopathy and DME, it’s always better to treat someone as early as possible.
PW: What surgical procedures are available for late DME?
Dr. Coates: Focal laser photocoagulation is the primary surgical option for patients with DME. There is some debate over whether pars plana vitrectomy is effective; however, research from the Diabetic Retinopathy Clinical Research Retina Network demonstrates no significant improvement in visual acuity between eyes that have had a vitrectomy versus those that have not.
Dr. Prasad: A newer surgical treatment involves a surgically implanted device that acts as a reservoir for anti-VEGF medication. The medication slowly releases into the vitreous cavity, providing a long-term steady-state level of anti-VEGF medication. Instead of needing intravitreal injections every four to six weeks, patients can have this device refilled in the clinic every 6 months.
PW: Are any other treatments available for advanced DME?
Dr. Prasad: Laser photocoagulation was a mainstay treatment for DME prior to anti-VEGF pharmacotherapy, but its use has decreased significantly over the past 10-15 years. However, macular laser photocoagulation can be useful in select patients with DME to decrease their need for ongoing injections or to treat recalcitrant DME.
Dr. Liu: One novel approach being investigated involves the possible long-term benefits of injecting sustained-release anti-VEGF medications even before diabetic retinopathy and DME manifest and whether doing so improves overall visual outcomes.
PW: What unmet needs remain in advanced DME?
Dr. Coates: Treatment frequency increases patient chair time and further strains already busy retina practices, and longer-lasting treatments would reduce the frequency of follow-up visits. Currently, most anti-VEGF treatments require injections at least monthly.
Dr. Prasad: Patients with DME need to be identified and treated early in their disease course to avoid irreversible vision impairment. In some patients with severe or chronic DME, visual outcomes can be disappointing despite resolution of macular edema with medical treatments. Vision may be limited by macular ischemia, photoreceptor disruption, retinal atrophy, or subretinal fibrosis, and we currently do not have therapies to prevent or reverse these effects.
Dr. Liu: Making medications last longer is a current research effort. Also, treatments, regardless of their duration, are typically repeated, so in the real world, loss to follow-up is fairly high.
This is an important public health issue involving the social determinants of health. To lower the incidence of retinopathy and DME, we need a public health approach that enables better screening for prediabetes or diabetes, better systemic control, and the ability to keep track of patients so they regularly return for treatments.
PW: Is there anything else you would like to mention?
Dr. Chhablani: Early detection and a multidisciplinary approach are key. Stay aware and updated on current available options and customize your treatment for each patient.
Dr. Coates: Healthcare providers outside eye care need to ensure that patients with diabetes, especially if poorly controlled, are being screened at least annually with a dilated fundus exam by a qualified eye care provider. Any patient with diabetes who complains about vision changes should be referred to an eye care provider to evaluate for possible DME.
Dr. Prasad: Evidence is growing that newer categories of oral hypoglycemic agents can increase the risk for DME. Also, systemic illnesses, including anemia, infections, and renal dysfunction, can negatively impact diabetic retinopathy and DME. Ophthalmologists, primary care physicians, and endocrinologists need to be in close communication regarding changes in medications or systemic health that can impact their patients’ ocular health.
Dr. Liu: In diabetes, the retina may look normal on examination. But in-depth analysis such as OCT may detect very early subtle changes the human eye cannot see. These changes may be on a molecular or cellular level beyond our current understanding. I won’t be surprised if, in the next 5 to 10 years, the definition of diabetic retinopathy changes.
From day one, doctors need to explain to each patient with diabetes that diabetes, diabetic retinopathy, and DME are chronic and that to ensure optimal outcomes, we need to maintain a long-term relationship.
