Benefits of lutein: MERG study shows improved VA

Birmingham, AL-The results of the second phase of the multifocal electroretinogram (MERG) study indicated that patients with category 3 dry (non-advanced) age-related macular degeneration (AMD) can achieve increased and sustained visual acuity (VA) levels with administration of the correct carotenoids, vitamins, and minerals, said John O. Mason III, MD.

At 2 months and 2 years after treatment with supplementation, patients had a mean improvement in MERG recordings of 16% (range 2% to 26%) compared with baseline, investigators found. These patients also had corresponding increases in VA. The MERG results in the untreated controls decreased over time.

In this study, five patients (10 eyes) with dry AMD received supplementation (Macular Health Eye Vitamin, Macular Health LLC) and five patients (10 eyes) with dry AMD served as untreated controls. Treatment for the patients receiving supplementation included high-dose beta carotene and zinc, vitamin E, vitamin C, copper, 10 mg lutein, and zeaxanthin, once daily.

The supplement formulation is similar to that used in the Age-Related Eye Disease Study (AREDS), with the exception that the original AREDS formulation administered to patients with category 3 dry AMD contained vitamin A and not lutein or zeaxanthin. In the AREDS study, the patients ultimately lost VA due to AMD changes, such as increased drusen and pigmentary changes in the macula.

Dr. Mason said he believes that lutein is responsible for the improved MERG results and increased VA in his patients.

"In the 1-year Lutein Antioxidant Supplementation Trial, lutein actually [was found to improve] the vision of some patients with dry AMD," Dr. Mason said. "We believe that the addition of lutein and zeaxanthin to the AREDS-like formula actually caused our patients to have an increase in their MERG [recordings]."

Improvements at 2 months, 2 years

A group of Italian investigators reported the same improvements at 2 months as those of Dr. Mason and colleagues; however, they believe they are the first to show this result at 2 years.

Dr. Mason reported that at 2 months the results of MERG testing showed increased amplitude densities in the patients treated with supplementation and no change in the amplitude densities in the patients who did not receive supplementation. At the 2-year time point, patients treated with supplementation had sustained improvements in MERG results and VA increases. At both time points, patients receiving supplementation had significant improvements in the amplitude densities in the N1 (p = 0.002) and P1 (p = 0.002) waves in all six rings.

The control patients over time had decreases in the MERG results. At the start of the study, the mean VA was 20/30, and at the 2-month and 2-year time points, the VA improved to a mean 20/25 in patients treated with supplementation.

It is not possible to speculate now whether patients with more severe AMD would realize a similar increase in VA and MERG with the supplement, according to Dr. Mason.

"We definitely saw this improvement in patients with category 3 dry AMD, but we can't say the same about patients with the severe form of the disease," he said.

"This is the first time in my career that I have actually seen patients with dry AMD who have had improvements in vision and in the MERGs as a result of taking carotenoid, vitamin, and mineral supplements," he said. "The MERG recordings showed continued macular function improvement in patients [treated with] supplementation and may aid the assessment of retinal function in dry AMD trials."

Dr. Mason and colleagues will continue to follow these patients in a phase II study to determine the longer-term effects of supplementation on dry AMD. They also will perform MERG testing on patients with category 3 AMD who are taking the supplement with the addition of omega-3 fatty acids. The investigators hope to report 3-year data at the 2010 annual meeting of the American Academy of Ophthalmology.