Estimated reading time: 6 minutes
After being diagnosed with diabetic macular edema (DME), you may be wondering what the treatment options are. The front-line therapy for combatting DME is anti-VEGF injections. Anti-VEGF therapy did not become widely used until the early 2000's, however. Before these drugs were approved for treating DME, laser therapy was the primary treatment. Today, laser therapy is often considered a second-line therapy, something to be used if anti-VEGF injections are not effective. They do still have a place in treatment! It is important to understand how laser therapy works, its benefits and risks, and how it can be used alongside other treatments for DME. Here is a breakdown from PatientsLikeMe.
What is Laser Therapy?
The History of Treatment
Laser therapy, also called laser photocoagulation, is a medical procedure that uses a focused beam of light to target and seal leaking blood vessels in the retina. By doing this, it helps reduce swelling and prevent more damage to the macula. Traditional laser therapy was called focal or grid laser therapy when it was first developed. There were two ways that scientists thought it helped with DME. The first is that laser therapy destroyed the cells that consumed oxygen. This let the eye itself get more of the oxygen supply from the blood. The second effect was that small scars created by the laser help the retina absorb excess fluid.
However, this conventional treatment had its limitations! Only around 3% of patients regained significant vision. It could also cause permanent scars in the retina, which could itself lead to vision loss. Finally, anti-VEGF therapies were more effective, making laser therapy obsolete as a first-line treatment. Anti-VEGF (vascular endothelial growth factor) medications work by blocking a protein that causes abnormal blood vessel growth and leakage in the retina. These injections have been shown to be highly effective in improving vision and reducing swelling in the macula. Because of their success, many doctors now use anti-VEGF injections as the primary treatment for DME.
Modern Approaches
Fortunately, there are some new laser treatments that are being developed that limit the damage to the retina while still treating the condition!
Subthreshold Micropulse Diode Laser Therapy (SDM)
SDM uses tiny pulses of laser energy instead of a continuous beam. Doctors target an area called the retinal pigment epithelium (RPE) without harming the surrounding cells. The RPE is a thin layer of cells between the retina and a layer of blood vessels at the back of the eye. One study on SDM showed that 70% of patients who got the treatment had their DME resolved within six months. Another study found that 85% of patients had stable or improved vision after one year.
Selective Retinal Therapy (SRT)
SRT is another treatment that selectively targets damaged RPE cells without harming the retina. Like SDM, SRT uses short pulses of laser energy, but this time they are all in the green light spectrum. This energy is absorbed by the pigment cells in the retina, which leads to selective regeneration of the damaged cells. Some studies have found that this treatment is even less damaging than SDM and stimulates natural healing of the retina. For example, this study of carefully selected patients showed that 84% saw improvement.
The Benefits and Risks of Laser Therapy
Benefits
While not the go-to treatment for all DME, laser therapy does have a number of significant benefits. The first, and most practical, is that it requires fewer sessions compared to anti-VEGF injections. Those therapies need to be given every few weeks. What often happens in the real world is that people miss treatments. They skip appointments or can't make sessions. The more you ask of a patient, the more likely it is they may not adhere to a more complicated treatment plan.
Laser therapy is less of a time burden, making it an appealing option for some. It can also be combined with anti-VEGF therapy! For patients who do not respond fully to anti-VEGF treatment, laser therapy can be used as an additional strategy to control swelling. Laser therapy is also an option for patients who cannot get anti-VEGF injections. Some people who have medical conditions like a recent stroke or heart attack have to avoid anti-VEGF treatments.
Risks
Laser therapy does take some time to show results. Often, between two and three months. The laser, particularly for the older treatment techniques, can also cause burns. These burns may result in blind spots if they are too close to the macula. Laser therapy can also leave scars which can expand over time. This may affect vision as well.
Laser Therapy and Anti-VEGF
Although anti-VEGF therapy is the preferred first-line treatment, laser therapy still has an important role in managing DME. It is used for patients who have non-center-involved DME, which is when swelling is not in the central macula. For patients with a good baseline vision (20/25 or better) and controlled blood sugar, laser therapy is also preferred. Certain people who are at a high risk for cardiovascular complications cannot receive anti-VEGF injections. That makes laser therapy the first-line therapy.
Combining The Two Treatments
Many patients with DME actually benefit from a combination of laser therapy and anti-VEGF injections. In DRCR.net Protocol T clinical trial many patients still required laser therapy after initial anti-VEGF treatment especially if the response plateaued. Laser therapy can help reduce the number of injections needed over time and provide a longer-lasting effect between treatments. Depending on a patients’ condition doctors will start administering anti-VEGF to lower swelling in the eye. They will then add laser therapy if there is still swelling after several injections. Doctors will monitor progress and the patient's response over time to adjust treatment as needed.
New advancements in laser technology are making treatments safer and more effective. While anti-VEGF therapy has become the standard of care for DME, laser therapy is still a valuable tool in managing the disease. As technology continues to advance, laser therapy will likely play a role in the fight against DME, offering more effective and safer solutions for preserving vision.
Taking control of your health has never been easier with PatientsLikeMe, a platform that empowers you to manage your wellness journey proactively. PatientsLikeMe offers tools to track your symptoms, treatments, and outcomes. Click below to join today!