With longer-acting therapies, is OCT monitoring advisable between injections?
Click Here to Manage Email Alerts
Click here to read the Cover Story, "Experts weigh current, future options for AMD management."
Yes because fluid dynamics are variable
Longer-acting drugs have been a great addition to our armamentarium.
However, from the studies and our own experience, we have learned that they are not 100% effective in all patients and that with the longer intervals in between injections of 16, 20 or 24 weeks, some patients may have attrition at certain periods of time. And certainly, not 100% of patients are able to achieve the full interval of re-treatment. The clinical trials did intermediate monitoring in those patients, and I believe this is going to be necessary for us, regardless of these drugs being more durable.
Through home OCT studies and other technologies, we have been able to find that fluid dynamics are variable. We have also learned that there is not always a correlation between OCT markers and vision. There may be reduction in retinal thickness without any sort of changes in visual acuity or, vice versa, visual acuity changes that do not match the reductions in fluid. In many cases, there is a disconnect between OCT and vision, and OCT rather than vision is currently considered the gold standard to guide re-treatment decisions. It is therefore important to monitor patients in between treatments to see what the fluid dynamic changes are. Intermediate OCT monitoring will also be helpful to better understand the best treatment interval for each individual patient. You may, for instance, see fluid recur on week 12 and treat rather than have the patient come back at week 16 and be treated when fluid has accumulated for a month. That intermediate monitoring will help to determine what the next steps should be, leading to better long-term vision outcomes.
Personally, with patients on 20-week intervals, I would schedule a visit at 10 weeks to determine if they are still stable. Even with injections every 12 weeks, there could be an argument made to see the patients in between, just to make sure they are not having adverse issues. However, 3 months is a reasonable time to wait, but with treatments every 16 weeks and beyond, I would definitely recommend splitting that time frame and calling the patients for a quick picture at around 10 weeks to make sure that the retina is dry.
Rishi P. Singh, MD, is a Healio | OSN Associate Medical Editor.
No because it would add unnecessary burden
We are fortunate to have these longer-acting agents, and we have great clinical trial data showing us that extending treatment intervals without imaging in between is safe in terms of the final visual outcomes.
Historically, in clinical practice, we have largely used treat and extend as a dosing schedule in which we do not perform OCT imaging in between injections. If we were to take these longer-acting agents and still bring patients into the office for imaging visits, we would give up the benefits of extending the intervals between injections, and we would defeat the purpose of reducing the treatment burden for the patient. A great part of that burden was from coming into the office for eye exams and OCT, which was part of the old as-needed approach that most of us have abandoned long ago. Intermediate OCT monitoring, now that we have the opportunity to extend the intervals between injections even further, would frankly take us back to treating patients on an as-needed basis. What would be the presumptive advantage to the patients? They would be losing the benefit in terms of visit burden with likely no gains in terms of final visual outcomes. If you look at the clinical trials with the new longer-acting drugs, the vast majority of patients do well in the study arm with extended treatment intervals as well as in the fixed-interval comparator arm.
When I switch patients to a longer-acting drug, Vabysmo (faricimab, Genentech) or Eylea HD (aflibercept 8 mg, Regeneron), initially I might keep them at the same interval I used before the switch. Then, if I see that I have a better drying result, I cautiously extend. Typically, once patients find their best extension interval, they tend to stay there and be stable, but you can safely adjust the schedule back downward should that not be the case. I have several patients at 16-week intervals, and they love it. Of course, I stress the importance of monitoring their vision one eye at a time and to call us as soon as possible if they notice any changes in vision. I have some patients who go longer than 16 weeks, and at some point, we have to involve them in the decision-making process. If they feel uncomfortable going that long because they are monocular, for instance, or simply because they were used to a tighter interval, we can schedule some extra visits in between.
In the future, with the potential approval of Home OCT (Notal Vision), things might change again, and we may welcome the opportunity to have our patients regularly monitor themselves between injections because we will no longer be talking about a burden.
Mark R. Barakat, MD, is director of research at the Retina Macula Institute of Arizona and clinical assistant professor at the University Arizona College of Medicine in Phoenix.
Collapse
Read more about
Click Here to Manage Email Alerts