AMD: From prevention to detection and back

June 29, 2013

 

San Diego-Optometry’s Meeting attendees had an excellent opportunity to learn about the intricacies of age-related macular degeneration (AMD) in the presentation, AMD from A to Z. Steven Ferrucci, OD, FAAO, Kimberly Reed, OD, FAAO, and David Lewerenz, OD, FAAO, presented at the informative session.

The session began with details on the latest therapies aimed at inhibiting vascular proliferation while preventing damage to photoreceptors. Various agents are currently being used as intravitreal injections, including Macugen (pegaptanib sodium), Lucentis (ranibizumab), 
Avastin (bevacizumab), and Eylea (aflibercert). Lucentis is widely used and, according to the ANCHOR study, 94% of patients treated with 0.3 mg had stable or improved vision vs. 64% with Visudyne. Furthermore, 36% had a gain of 15 letters or more. Lucentis is recommended every 4-6 weeks for 2 years but, unfortunately, costs approximately $2500 for medication alone, though that price is coming down a bit, the presenters agreed.

In addition to the price drop, new research from the PRONTO study looked at alternative dosing schedules. It appears that results with Lucentis can be very similar to those in the original studies when injections are given monthly for only 3 months. After the initial 3 months, an OCT should be performed to determine whether future injections can be every other month or longer.

Many physicians have been turning to lower-cost Avastin, even though the drug is not approved for use in the eye due to its larger molecule size. For this reason, the Complications of Age-Related Macular Degeneration Treatment Trial (CATT) results were greatly anticipated. The findings at 1 year showed equivalent effects on visual acuity with Lucentis vs. Avastin. Specifically:

  • Lucentis monthly 8.5 letters gained

  • Avastin monthly 8.0 letters gained

  • Lucentis PRN 6.8 letters gained


  • Avastin PRN 5.9 letters gained

Eylea entered the scene next. Studies of this drug show that 95% of patients receiving 2 mg q 2 months achieved maintenance of vision vs. 94% with Lucentis monthly. They also report an 8.9 letter mean improvement of vision, vs. 9.4 with Lucentis monthly. A benefit of Eylea is cost; it’s generally less than Lucentis, but still more than off-label Avastin.

“Now that we have great treatments, we should try to diagnose these patients earlier,” noted Dr. Ferrucci. “The sooner we can start antiVEGF, the better.”

The presenters said there is a great deal of diagnostic equipment being developed. The AdaptDx, FAF, and MSI are all being looked at for earlier detection of disease. Similarly, PHP and OCT are being considered as a means for earlier detection of conversion from dry to wet AMD. Also, MPOD 
and genetic testing are being investigated in terms of evaluating risk factors.

“Is AMD in our DNA?” The presenters agreed that AMD is a genetic disease with known markers accounting for at least 70% of the population’s attributable risk. The other 30% is environmental/lifestyle.

There are several genes that have been linked to AMD. Further, genetic factors and risk are more than additive, said Dr. Ferrucci. For example, current smokers are 2.4 times more likely to have AMD. But, that same smoker with genetic markers is 34 times more likely to get AMD.

Another compelling topic presented in this course was information about new treatments on the horizon. The presenters pointed out that currently there are 894 studies evaluating AMD. Some of the highlights included Fovista, which gave 59% of patients improvement of 3 lines or more when used in conjunction with an antiVEGF. There is also a lot of investigation into VEGF eye drops, since injections are a burden. Implants that slowly release medication into the eye are also being investigated, as are genetic treatments and stem cells.ODT