Retinitis pigmentosa (RP) has a prevalence of 1 in 4,000 people and an estimated 50,000 to 100,000 people are affected in the United States. Since no accepted medical or surgical treatment can stop the course of the disease, a number of studies have accessed whether nutritional supplements could improve functional vision in RP patients or slow the progression of the disease.
Lutein, a component of the macular pigment, is an essential nutrient that has been shown to have a protective effect on the macula. This protection stems from the antioxidant properties of lutein, and its ability to attenuate damaging blue wavelengths of visible light.
A number of studies have shown improvements in visual function following lutein supplementation in both healthy individuals and patients with age-related macular degeneration. Two pilot studies suggested lutein supplementation could improve visual function in RP patients as well.(1,2) In both trials, RP patients were supplemented with 10-40 mg/day lutein for up to six months. Results demonstrated that lutein supplementation significantly improved visual field area.
A breakthrough new study was published online in the Archives of Ophthalmology that confirms previous findings and offers new hope for the prevention of visual field loss in patients suffering from retinitis pigmentosa.(3)
In this randomized, placebo-controlled, double-blind study conducted by lead author Eliot Berson, M.D. (Berman-Gund Laboratory at Harvard Medical School), two hundred and twenty-five non-smoking patients aged 18-60 years with retinitis pigmentosa received either 12 mg of FloraGLO® Lutein or a placebo tablet daily. All patients received 15,000 IU/day of vitamin A as retinyl palmitate and throughout the study period were advised to eat 1 to 2 servings of oily fish per week to increase their intake of long chain omega-3 polyunsaturated fatty acids (PUFA).
Patients were supplemented over the course of four years, and their serum lutein levels, macular pigment optical density, and visual field were assessed on a yearly basis. Static perimetric sensitivities were measured with the 30-2 program size V target in the Humphrey Field Analyzer (HFA) II. The full-field 30-Hz cone ERG amplitude was measured among those with an amplitude of 0.68 mV or more pre-treatment. Visual acuity (Early Treatment Diabetic Retinopathy Study), the total point score to a size V target with the 60-4 program, and total point score to a size V target with the HFA 30-2 and 60-4 programs combined were also studied.
Results of the trial were as follows:
Over the longer term, the authors estimated that supplementation with a highly bioavailable source of lutein, i.e., FloraGLO Lutein with Actelease Technology, would preserve midperipheral visual field sensitivity among RP patients also taking a vitamin A supplement and eating an oily fish diet for 3 to 10 additional years.
Citations
1. Dagnelie G et al., 2000. Lutein improves visual function in some patients with retinal degeneration: a pilot study via the Internet. Optometry. 71(3):147-64.
2. Bahrami H et al., 2006. Lutein supplementation in retinitis pigmentosa: PC-based vision assessment in a randomized, double-masked, placebo-controlled clinical trial [NCT00029289] BMC Ophthalmology. 6:23.
3. Berson et al. 2010. Clinical trial of lutein in patients with retinitis pigmentosa receiving vitamin A. Archives of Ophthalmology. 128(4):403-411.
Lutein, a component of the macular pigment, is an essential nutrient that has been shown to have a protective effect on the macula. This protection stems from the antioxidant properties of lutein, and its ability to attenuate damaging blue wavelengths of visible light.
A number of studies have shown improvements in visual function following lutein supplementation in both healthy individuals and patients with age-related macular degeneration. Two pilot studies suggested lutein supplementation could improve visual function in RP patients as well.(1,2) In both trials, RP patients were supplemented with 10-40 mg/day lutein for up to six months. Results demonstrated that lutein supplementation significantly improved visual field area.
A breakthrough new study was published online in the Archives of Ophthalmology that confirms previous findings and offers new hope for the prevention of visual field loss in patients suffering from retinitis pigmentosa.(3)
In this randomized, placebo-controlled, double-blind study conducted by lead author Eliot Berson, M.D. (Berman-Gund Laboratory at Harvard Medical School), two hundred and twenty-five non-smoking patients aged 18-60 years with retinitis pigmentosa received either 12 mg of FloraGLO® Lutein or a placebo tablet daily. All patients received 15,000 IU/day of vitamin A as retinyl palmitate and throughout the study period were advised to eat 1 to 2 servings of oily fish per week to increase their intake of long chain omega-3 polyunsaturated fatty acids (PUFA).
Patients were supplemented over the course of four years, and their serum lutein levels, macular pigment optical density, and visual field were assessed on a yearly basis. Static perimetric sensitivities were measured with the 30-2 program size V target in the Humphrey Field Analyzer (HFA) II. The full-field 30-Hz cone ERG amplitude was measured among those with an amplitude of 0.68 mV or more pre-treatment. Visual acuity (Early Treatment Diabetic Retinopathy Study), the total point score to a size V target with the 60-4 program, and total point score to a size V target with the HFA 30-2 and 60-4 programs combined were also studied.
Results of the trial were as follows:
- Mean serum lutein levels were higher in the lutein group as compared to the placebo group (p<0.001) at one year and were maintained over the course of 4 years.
- The lutein group showed a significantly greater increase in macular pigment optical density (MPOD) over 4 years compared with the control group (p<0.001).
- During the 4 years of supplementation, a decline in visual field area was apparent in all patients. However, a significantly lower decline in midperipheral visual field sensitivity was observed in the group supplemented with lutein (p=0.05) after 4 years. The lutein group lost, on average, 27 dB/y while the control group lost 34 dB/y.
- When patients were categorized by lutein serum levels, patients in the highest quartile of serum lutein levels had a significantly decreased rate of midperipheral visual field sensitivity (p=0.01) loss compared with those in the lower 3 quartiles. The mean rate of decline of HFP 60-4 sensitivity was 21dB/y for those in the highest quartile of serum lutein level vs 33 dB/y in the lower 3 quartiles.
- When patients were categorized by MPOD levels, the rate of decline of midperipheral visual field sensitivity was significantly slower among those in the highest quartile of change in MPOD (18 dB/y) versus the rate among those in the lower 3 quartiles (34 dB/y) (p=0.006).
- No adverse effects of lutein supplementation were noted during the 4 years of supplementation.
Over the longer term, the authors estimated that supplementation with a highly bioavailable source of lutein, i.e., FloraGLO Lutein with Actelease Technology, would preserve midperipheral visual field sensitivity among RP patients also taking a vitamin A supplement and eating an oily fish diet for 3 to 10 additional years.
Citations
1. Dagnelie G et al., 2000. Lutein improves visual function in some patients with retinal degeneration: a pilot study via the Internet. Optometry. 71(3):147-64.
2. Bahrami H et al., 2006. Lutein supplementation in retinitis pigmentosa: PC-based vision assessment in a randomized, double-masked, placebo-controlled clinical trial [NCT00029289] BMC Ophthalmology. 6:23.
3. Berson et al. 2010. Clinical trial of lutein in patients with retinitis pigmentosa receiving vitamin A. Archives of Ophthalmology. 128(4):403-411.
