Macular degeneration: Pro-Re-Nata / Treat-and-Extend
When diagnosed with wet macular degeneration, there are currently two options for treating patients with injection therapy. The goal is to have the least number of injections possible while ensuring the best possible treatment result. The two forms of therapy, Pro-Re-Nata and Treat-and-Extend, enable us to find an individually suitable scheme for each patient and make sure that no one is neither over- nor under-treated.
Difference between the Pro-Re-Nata an Treat-and-Extend schemes
Pro-Re-Nata therapy is the most commonly used treatment of wet macular degeneration in Germany. Patients are always treated with a series of injections: they receive three injections, one every four weeks. After this series of injections, there is a short break in therapy. It is checked how long the macula remains dry. The controls then take place every four weeks. Here, a slice image of the center of the retina is created using optical coherence tomography, the so-called OCT. It is checked whether the findings are still dry during the therapy break. If there are no signs of activity, i.e. no macular edema, no bleeding or other changes that indicate an active, moist macula, the pause continues. Control checks then continue to take place every four weeks. Only when there is renewed activity is the therapy given again with a series of three injections, one every four weeks. Pro-Re-Nata therapy has proven its worth in the past and is used most frequently in our practice.
In addition to Pro-Re-Nata therapy, there is also Treat-and-Extend therapy. Treat-and-Extend therapy is used in patients who show increased disease activity. With them, the wet macular degeneration occurs particularly aggressively. This means that in these patients the disease breaks out again shortly after injection therapy. Instead of Pro-Re-Nata therapy, it might make more sense in these cases to use Treat-and-Extend therapy. Here, the goal for these patients is to find the injection interval that is best suited to keep the macula dry.
What are the individual advantages of both forms of therapy?
With Pro-Re-Nata therapy, the patient has the advantage that he has fixed appointments and can plan well about four weeks in advance. Many patients remain dry for a long time after the three injections of the Pro-Re-Nata therapy. For these patients, Treat-and-Extend therapy would mean over-treatment. However, it is useful for particularly chronic patients who relapse very frequently and quickly. The Pro-Re-Nata therapy is also better suited for bilateral wet macular degeneration. Studies compared the two therapy schemes after two years: success and results for the patients are ultimately identical.