Macular pigment and serum zeaxanthin levels with Goji berry supplement in early age-related macular degeneration

Abstract

Aim: To evaluate the efficacy of Goji berry supplementation on improving macular pigment, serum zeaxanthin levels and visual acuity in patients with early age-related macular degeneration (AMD).

Methods: A total of 114 patients (aged from 51 to 92y, mean age 69.53±8.41y) with early AMD were enrolled in our prospective, randomized controlled study. The included patients were assigned randomly to the Goji group (n=57) with 25 g of Goji berries supplementation per day for 90d and the control group (n=57) with their normal diet for 90d. Macular pigment optical density (MPOD) was measured using heterochromatic flicker photometry (HFP). The levels of serum lutein (L)/zeaxanthin (Z) were analyzed using high-performance liquid chromatography (HPLC). MPOD, serum L/Z levels and best corrected visual acuity (BCVA) were recorded at baseline and 90d.

Results: In the Goji group, there were no statistically significant differences in the serum L levels between the baseline (0.199±0.149 µmol/mL) and 90d (0.203±0.181 µmol/mL) (t=-0.186, P=0.850); however the serum Z levels were increased at 90d (0.101±0.087 µmol/mL) compared with those at the baseline (0.029±0.032 µmol/mL) (t=6.412, P<0.001). Patients treated with Goji berry for 90d showed an elevated MPOD (0.877±0.202 DU) from the baseline (0.731±0.205 DU) (t=-4.741, P=0.000). In contrast to the control group, the serum Z levels and MPOD were higher in the Goji group at 90d (both P<0.05). At 90d, patients with Goji berry supplementation had a relative decrease in BCVA (0.21±0.18 logMAR) compared with the baseline (0.27±0.20) (t=2.397, P=0.020).

Conclusion: Overall, daily supplementation with Goji berry for 90d improves MPOD by increasing serum Z levels rather than serum L levels in early AMD patients. Goji berry may be an effective therapeutic intervention for preventing the progression of early AMD.

Keywords: Goji berry; early age-related macular degeneration; zeaxanthin.

Figure 1. Representative of color fundus photography and OCT photographs in early AMD patients

A, B: Fundus and OCT photographs showed a soft distinct drusen at baseline; C, D: Fundus and OCT photographs showed that the drusen gradually diminished at the same position as arrowed after 90d of Goji berry supplementation.

Figure 2. The standard sample was used as a reference

Z₁ (3R, 3′S)-zeaxanthin (0.522 µg/mL), Z₂ (3R, 3′R)-zeaxanthin (0.398 µg/mL) and L (3R, 3′R, 6′R)-lutein (0.582 µg/mL) are arrowed.

Figure 3. Chromatogram of extracted serum from a single volunteer

Peaks of zeaxanthin and lutein (identified by comparison with injection of pure zeaxanthin and lutein) are arrowed.

Figure 4. Associations between serum Z levels and MPOD in the Goji group at 90d

The linear regression equation is Y(MPOD)=0.882-0.108X(serum Z levels).