TOZAL Study: An open case control study of an oral antioxidant and omega-3 supplement for dry AMD

Abstract

BackgroundThe primary objective of this prospective study was to measure the change from baseline in visual function – Best-Corrected Visual Acuity (BCVA) via the Early Treatment Diabetic Retinopathy Study (ETDRS) chart, contrast sensitivity, central 10 degree visual fields and retinal imaging (angiograms and photographs) at 6 months in subjects with atrophic (dry) age-related macular degeneration treated with a targeted nutritional supplement.Methods37 mixed gender patients with a mean age of 76.3 +/- 7.8 years were enrolled at 5 independent study sites and received standard of care with a novel formulation of a nutritional supplement. Results were compared to a placebo cohort constructed from the literature that was matched for inclusion and exclusion criteria. A paired t-test was used to test a null hypothesis and a two-sided alpha level of 0.05 was used to determine statistical significance.Results76.7% of subjects receiving the nutritional supplement demonstrated stabilization or improvement of BCVA at 6 months. Subjects gained an average of 0.0541 logMAR or one-half of a line of visual acuity (VA) over the 6-month period. There was a statistically significant improvement in VA from baseline with P = .045. The results provide strong evidence that the treatment being studied produces an improvement in VA.ConclusionTreatment with this unique nutritional supplement increased VA above the expected baseline decrease in the majority of patients in this population with dry macular degeneration. The results of the TOZAL study agree with the LAST and CARMIS studies and are predictive for positive visual acuity outcomes in the AREDS II trial. However, patients will likely require supplementation for longer than 6 months to effect changes in additional visual parameters.

Macular pigment in retinal health and disease

“…These results were in agreement with previous findings from the same group, who found significant morphological changes in MP at the central retina within 24 weeks, but no improvement in visual function until 48 weeks [76]. Similarly, the results of the TOZAL study also indicated that AMD patients were likely to require supplementations for at least 6-months to obtain positive changes in VA outcomes [77]. Patients with late AMD compared with early AMD tended to have a less significant improvement in VA, and this finding was attributed to the loss of macular photoreceptors in the late stage of the disease [75].…”

Omega-3 Fatty Acids and Age-Related Macular Degeneration

“…Although there have been earlier interventional studies, some used less rigorous methodologies or multiple supplements making it impossible to differentiate the effects of omega-3 from other components [21,22]. There have been, however, two well-conducted randomised, double-blind controlled trials of omega-3 in the prevention of AMD, although both studies raise some questions.…”

Current and future strategies for nonexudative age-related macular degeneration

“…The Lutein Zeaxanthin Eye Accumulation (LUXEA) study demonstrated that supplementation with carotenoids, lutein and zeaxanthin could improve mesopic contrast acuity thresholds and visual performance at low illumination [18]. In 2007, the results of the Taurine, Omega-3 Fatty Acids, Zinc, Antioxidant and Lutein (TOZAL) trial showed that 76.7% of subjects treated with the formulation could improve or maintain their visual acuity (VA), with up to 0.5 lines of VA improvement at 6 months [19]. Currently, in AREDS2, patients with either bilateral large drusen or large drusen in one eye and advanced AMD in the other will be given a combin ation of the original AREDS formulation, with either high doses of xanthophylls lutein (10 mg) and zeaxanthin (2 mg), or omega-3 fatty acids (350 mg docosahexaenoic acid [DHA]/650 mg eicosapentaenoic acid [EPA]), or both.…”