Study: Combined Supplements Improve Visual Acuity in Subjects with Dry Macular 2007

Combined Supplements Improve Visual Acuity in Subjects with Dry Macular Degeneration

Author: Steve Austin, N.D.

Reference: Cangemi FE. TOZAL study: an open case control study of an oral antioxidant and omega-3 supplement for dry AMD. BMC Ophthalmol 2007;7:3-12.

Design: Despite the article title (see above), this was a controlled, double blind (though not randomized) intervention trial.

Participants: Subjects included 37 adults with age-related macular degeneration (AMD). The control was a constructed cohort of similar patients from a previous report matched for both inclusion and exclusion criteria.

Study Medication and Dosage: Study subjects received retinol (10,000 IU/d), beta-carotene (28,640 IU/d), vitamin C (452 mg/d), vitamin E (200 IU/d), zinc (56 mg/d), copper (1.6 mg/d), taurine (400 mg), EPA (180 mg/d), DHA (120 mg/d), lutein (8 mg/d), and zeaxanthin 400 mcg/d). The control subjects had also received vitamin C (400 mg/d), vitamin E (200 IU), zinc (40 mg), and beta-carotene (300 IU/d), but none of the other supplements.

Primary Outcome Measures: Changes from baseline in visual function were measured using a variety of standard research tools (e.g., Best-Corrected Visual Acuity (BCVA) via the Early Treatment Diabetic Retinopathy Study (ETDRS) chart, contrast sensitivity, and retinal imaging).

Key Findings: 77% of subjects receiving the full complement of supplements demonstrated stabilization or improvement of BCVA at 6-months. These same subjects saw small improvements in visual acuity that achieved statistical significance (p<0.05). As expected, mean visual acuity declined in the control group.

Practice Implications: Conventional medicine has little to offer many patients with this all too common disease (incidence: >15,000,000 Americans >60 years of age), now the leading cause of irreversible blindness in the elderly. Progressive deterioration is the norm, though the rate of deterioration can vary significantly. Dry AMD is the most common form. Previous research has suggested the possibility that a wide variety of nutritional supplements help patients with AMD, such as lutein, fish oil, zinc, antioxidants, or some combination thereof. This trial combines most of these supplements at easily attainable dose levels. The outcome--a halting of progression and the beginnings of a reversal--give healthcare practitioners a potential treatment plan from which to get started.

Interestingly, a standard control group was not part of the trial design not due to the cost, but rather because the independent review board determined that evidence supporting nutritional supplementation is now so strong that the standard of care demands some nutritional supplementation.