#25: Advances in Dry AMD Studies

Dry age-related macular degeneration (AMD) is associated with the formation of drusen as the phenotype of the disease. Although patients do not experience any change in vision, the appearance of drusen is considered a risk factor for the development of advanced AMD. To detect drusen, diagnostic imaging plays an important role.

For patients with drusen, both the AREDS 1 and AREDS 2 trials showed that the risk of developing an advanced form of AMD can be reduced significantly.

Drusen and geographic atrophy as seen with SPECTRALIS MultiColor fundus image and OCT

In the first AREDS trial, patients were randomized to treatment in 1 of 4 treatment groups: an antioxidant group (vitamin C 500 mg, vitamin E 400 IU, beta-carotene 15 mg); zinc (zinc oxide 80 mg/cupric oxide 2 mg); antioxidants plus zinc; or placebo. Results showed that the use of zinc plus antioxidants lowered the risk of progression to advanced AMD or visual loss in patients who had baseline moderate or advanced AMD.

Because of the link of beta-carotene and high-dose vitamin E to a variety of adverse events, however, the AREDS 2 trial was undertaken with these goals:

• To see if the addition of further antioxidants-specifically lutein and zeaxanthin (carotenoids), and docosahexaenoic and eicosapentaenoic acid (antioxidants)-to the AREDS vitamin formulation would further decrease risk of AMD; and

• Whether eliminating beta-carotene and lowering the dose of zinc would impact efficacy.

Blue laser autofluorescence of geographic atrophy as seen with SPECTRALIS BluePeak module Results of the trials showed that there was no additional benefit of adding further antioxidants to the AREDS regimen. Nevertheless, replacing beta-carotene with the combination of lutein and zeaxanthin led to a slight reduction in the risk of progression to advanced AMD with no increased risk of lung cancer. This is of particular relevance in smokers with AMD.

Several promising trials of therapeutic agents in dry AMD are also under way. In these trials, the effect of the drug is evaluated by monitoring the size of the atrophy with blue laser autofluorescence. Recently presented results from the MAHALO phase 2 trial showed that lampalizumab is effective in slowing the progression of disease among patients with atrophic AMD. Phase 3 trials of lampalizumab are currently in progress.