Dr. Mark Johnson reported on his results following 15 patients with wet AMD after a single dose of Avastin®. He found that the fluid within or under the retina resolved in 67% of the patients by the fourth week after the injection and that it had resolved in 73% of patients by eight weeks. There were three of the 15 patients who had continued resolution of the fluid between 4 and 8 weeks. He believed that these results indicate that Avastin can be injected at intervals of two months, (eight weeks), or perhaps even longer. Most retinal doctors have been giving Avastin at intervals of six weeks or even every four weeks.

We are still trying to figure out how to maximize the visual results while minimizing the number of injections. We could, as in the MARINA trial, just give Lucentis® every month for two years. This pretty much insures us the greatest chance of getting and keeping the retina dry and perhaps would give us the best visual results. But we also know that many of these patients really don’t need all of this injections since many stay stable for long periods of times after the first three injections.

We can also use schemes like used in the PRONTO study where we follow patients and treat only as needed. This will lessen the number of treatments from thirteen to about six during the first year. It means though that there will be times when the fluid has come back before it’s eliminated by the Lucentis or Avastin. Certainly having fluid in or under the retina for a long period of time is not good for vision. We don’t know how harmful it is for the fluid to be there for a few days or weeks but the PRONTO results were pretty good. Patients can always also return early if their vision gets worse but many times the fluid is seen on the OCT before the patient notices a loss of vision.

The Comparison of AMD Treatment Trials will help us answer this question because there are arms of the trial in which Lucentis and Avastin are given monthly and arms in which, after the first three injections, they are given only as needed.

The 30th annual meeting of the Macula Society was held May 30-June 2, 2007 in London. The meeting was attended by experts in macular disease from around the world. There were a number of papers updating the positive results of the various Lucentis® trials including reports from the following studies: PRONTO, ANCHOR, Extension Study 2508, HORIZON, and PIER. The Extension Study showed that intraocular injections of Lucentis were well tolerated for up to four years and that the positive visual results were maintained.

Dr. Carmen Puliafito presented an update from the PRONTO study. In PRONTO, patients with wet AMD were treated with three monthly injections of Lucentis. An injection was given at baseline, month one, and month two. Then the patients were followed monthly. An optical coherence tomography (OCT) exam was done at every visit and a fluorescein angiogram was done every three months. The patient received another injection of Lucentis only if:

They lost 5 or more letter of vision from the last visit
New neovascularization or hemorrhage was seen on clinical exam or fluorescein angiography
The OCT showed persistent or recurrent fluid in or under the retina
The OCT showed a increase central retinal thickness of 100µ or more
The OCT showed an increase in the height or breadth of a retinal pigment epithelial detachment.

It is not always possible to flatten a retinal pigment epithelial detachment with Lucentis so patients were not retreated if there was no fluid in the retina and the pigment epithelial detachment was stable.

The visual results from the PRONTO study were basically the same as the results from the MARINA and ANCHOR studies which means that on average, patients gained two lines of vision after two years of follow-up. Patients in the PRONTO study needed, on average, 5 injections per year for two years. Some patients needed only three injections and then were stable whereas other patients needed injections every month. At any given monthly visit, patients had about a one in three chance of needing another injection.

Most retinal experts are using variations of the PRONTO scheme meaning patients get three injections of Lucentis or Avastin® and are then followed if they are stable and without fluid. If patients have stable vision and no fluid, many retinal experts will gradually lengthen the time between appointments to two or even three months.

There is more to come soon from the Macula Society Meeting.

1. Puliafito, C., Rosenfeld, P., Lalwani, G., Fung, A., Michels, S., Dobovy, S., Feuer, W. “An OCT-Guided Variable-Dosing Regimen with Ranibizumab (Lucentis) in Neovascular AMD: Two Year Results of the PRONTO Study.”

[VIEW IN EXTERNAL VIDEO PLAYER]

Table of contents to all the videos: http://www.medrounds.org/protect-your-sight/videos/