Do they work? Injections for age related macular degeneration

By Igor Westra, M.D.

cross section of an eye showing the location of the macula at the back of the eye along with depictions of a normal, macula, wet macular degeneration and dry macular degeneration.

Anyone who has contact with the elderly will certainly know someone who has age related macular degeneration. It is the most common cause of irreversible legal blindness in the United States.

Fortunately, there is now treatment for the most aggressive form which is called the “wet” type where fluid forms under the retina disrupting the visual process. The new treatment consists of injecting an anti growth hormone into the patient’s eye. Initially, many ophthalmologists thought that after few shots of the medicine, the condition was controlled and the patient could be treated as needed. This approach has resulted in poor vision.

Studies have now been published comparing the real world results of macular degeneration treatments versus the results of clinical trials. The results were alarming because the real world results are nowhere near as rosy as what happened in the trials. So what went wrong? Do the drugs not work as well as predicted? The latest research confirmed that patients were not receiving the treatment as it was prescribed.

The recommended monthly treatment is a lot to ask from patients. New studies were designed to test decreasing the number of treatments needed. There were two methods of treatment that were tried: treat and extend versus as needed treatment. Treat and extend means treating at four weeks for a while and then when the disease seems to be controlled, extending the time between the treatments by one or two weeks. Usually this goes on to a maximum of an 8 to 12 week interval.

As needed means treating every four weeks until the disease appears controlled and then stopping the treatment. In research trials the patient would be seen every four weeks even when no injection was given. If the patient developed a leak it would be treated fairly promptly. In real life, patients were not seen as frequently, often only every three to 12 months. Predictably, in the real world it could be a long time before these patients received treatment even though the majority of patients have recurrences. Clinical trials showed that the “treat and extend” is superior to “as needed” treatment but both are much better than the real world results.

Vision is lost because patients are not receiving the treatment at the recommended time period and treatment is stopped at a much higher rate than predicted from the large studies. Some of my patients ask to greatly extend the time between injections or stop the injections for a while. They forget that this is a chronic disease; just like diabetes or high blood pressure, there is no medication that cures the disease. What would happen if we treated blood pressure this way? Surely many people would have strokes and heart attacks.

In the future we will have longer acting treatment or a cure for macular degeneration. In the meantime, today’s treatment means a lot of time spent in the doctor’s office but most of these patients will be able to continue to read and drive.