Retinopathy
Several conditions can cause damage to the retina of the eye. Long-term diabetes and high blood pressure are the most common causes of retinopathy. Partial or total blindness may indicate the presence of retinopathy.
Nutritional supplements that may be helpful: Free radicals have been implicated in the development and progression of many forms of retinopathy.
1 This is primarily the case in premature infants and anyone exposed to high levels of oxygen. Vitamin E is considered effective, at a level of 1,200 IU per day or more, for preventing and treating such problems.2 Vitamin E has also been shown in a limited investigation to protect people with very high cholesterol levels from developing retinopathy.3 Low vitamin C levels have been correlated to diabetic retinopathy.4 A combination of 500 mcg selenium, 800 IU vitamin E, 10,000 IU vitamin A, and 1,000 mg vitamin C taken each day for several years has been reported to improve diabetic retinopathy in one investigation.5Low blood levels of magnesium have been linked to retinopathy due to diabetes.
6 7 One study in black Africans with diabetes found that while blood magnesium levels were lower than in healthy people, the level was not related to retinopathy.8 Supplementing magnesium to help retinopathy has not been studied.In a preliminary study, one group of researchers proposed that supplementation of vitamin B6 could prevent diabetic retinopathy.
9 This has not yet been proven.One study investigated the effect of adding 100 mcg of vitamin B12 for one year to the insulin injections of fifteen children with diabetes.
10 Retinopathy was resolved in almost half of this group. Adults were not aided by vitamin B12. Consultation with a physician is necessary before adding injectable vitamin B12 to insulin.Bioflavonoids such as quercetin inhibit the enzyme aldose reductase.
11 This enzyme appears to contribute to worsening of diabetic retinopathy. Although human studies have not been done using quercetin to treat retinopathy, many doctors of natural medicine prescribe 400 mg of quercetin three times per day. Herbal inhibitors of aldose reductase are mentioned below.Are there any side effects or interactions? (Refer to individual supplement for complete information.) Vitamin E toxicity is very rare; supplements are widely considered to be safe.
Some individuals develop diarrhea after as little as a few thousand milligrams of vitamin C per day, while others are not bothered by ten times this amount. However, high levels of vitamin C can deplete the body of copper, an essential nutrient. It is prudent to ensure adequate copper intake at higher intakes of vitamin C (copper is found in many multivitamin/mineral supplements).
Selenium is very safe, although taking more than 1,000 mcg per day may cause loss of fingernails, skin rash, and changes in the nervous system.
Women who are or could become pregnant should take less than 10,000 IU (3,000 mcg) per day of vitamin A to avoid the risk of birth defects. For other adults, intake above 25,000 IU (7,500 mcg) per day can in rare cases cause headaches, dry skin, hair loss, fatigue, bone problems, and liver damage.
Taking too much magnesium often leads to diarrhea. Occasionally, this can happen at doses as low as 350–500 mg per day. Excessive magnesium intake is more serious, but it is rarely caused by magnesium supplements. People with kidney disease should not take magnesium supplements without consulting a physician.
Although side effects from vitamin B6 supplements are rare, at very high levels this vitamin can damage sensory nerves, leading to numbness in the hands and feet as well as difficulty walking. Vitamin B6 supplementation should be stopped if these symptoms develop. Pregnant and lactating women should not take more than 100 mg of vitamin B6 per day. For other adults, vitamin B6 is usually safe in amounts of 200–500 mg per day,
12 although occasional problems have been reported in this range.13 Any adult taking more than 100–200 mg of vitamin B6 per day for more than a few months should consult a doctor. Side effects from vitamin B6 become more common when intake exceeds 2,000 mg per day; consequently, this supplement level should be avoided.14Vitamin B12 supplements are not associated with side effects.
No clear toxicity has been identified with quercetin.
Herbs that may be helpful: Bilberry extracts standardized to contain 25% anthocyanosides have been recommended for diabetic and hypertensive retinopathy. Such an extract, when taken 200 mg three times per day, was found to benefit people with retinopathy in one study.
15A standardized extract of ginkgo has been shown to improve impaired color vision in people with diabetic retinopathy.
16 Most often, 60 mg of an extract is taken two to four times each day.As mentioned above for quercetin, some herbs are known to inhibit aldose reductase in the test tube. Most notable among these is licorice.
17 However, no herbal aldose reductase inhibitor has been studied for effectiveness in humans with diabetic retinopathy.Are there any side effects or interactions? (Refer to individual herb for complete information.) In recommended amounts, there are no known side effects with bilberry extract. Bilberry does not interact with commonly prescribed drugs, and there are no known contraindications to its use during pregnancy or lactation.
Ginkgo biloba is essentially devoid of any serious side effects. Mild headaches lasting for a day or two and mild upset stomach have been reported in a very small percentage of people using ginkgo. There are no known contraindications to the use of ginkgo by pregnant and lactating women.
Licorice products without the glycyrrhizin removed may increase blood pressure and cause water retention in some people. Long-term intake of products containing more than 1 gram of glycyrrhizin per day can cause these side effects. Deglycyrrhizinated licorice extracts do not cause these side effects.
Nutritional Supplements |
Herbs |
Homeopathic Remedies |
| Vitamin E | Bilberry | No homeopathy commonly used for this condition |
References:
1. Alieva ZA, Gadzhiev RV, Sultanov M. Possible role of the antioxidant system of the
vitreous body in delaying the development of diabetic retinopathy. Oftalmol Zh
1985;(3):142–45 (in Russian).
2. Johnson L, Quinn GE, Abbasi S, et al. Effect of sustained pharmacological vitamin E
levels on incidence and severity of retinopathy of prematurity: A controlled clinical
trial. J Pediatr 1989;114:827–38.
3. Runge P, Muller DP, McAllister J, et al. Oral vitamin E supplements can prevent the
retinopathy of abetalipoproteinaemia. Br J Ophthalmol 1986;70:166–73.
4. Sinclair AJ, Girling AJ, Gray L, et al. An investigation of the relationship between
free radical activity and vitamin C metabolism in elderly diabetic subjects with
retinopathy. Gerontology 1992;38:268–74.
5. Crary EJ, McCarty MF. Potential clinical applications for high-dose nutritional
antioxidants. Med Hypoth 1984;13:77–98.
6. Jialal I, Joubert SM. The biochemical profile in Indian patients with
non-insulin-dependent diabetes in the young with retinopathy. Diabetes Metabol
1985;11:262–65.
7. McNair P, Christiansen C, Madsbad S, et al. Hypomagnesemia, a risk factor in diabetic
retinopathy. Diabetes 1978;27:1075–78.
8. Erasmus RT, Olukoga AO, Alanamu RA, et al. Plasma magnesium and retinopathy in black
African diabetics. Trop Geogr Med 1989;41:234–37.
9. Ellis JM, Folkers K, Minadeo M, et al. A deficiency of vitamin B6 is a plausible
molecular basis of the retinopathy of patients with diabetes mellitus. Biochem Biophys
Res Commun 1991;179:615–19.
10. Kornerup T, Strom L. Vitamin B12 and retinopathy in juvenile diabetics. Acta
Paediatr 1958:47:646–51.
11. Varma D. Inhibition of aldose reductase by flavonoids: Possible attenuation of
diabetic complications. Prog Clin Biol Res 1986;213:343–58.
12. Gaby AR. Literature review and commentary. Townsend Letter for Doctors and Patients
Jun 1990;338–39.
13. Parry G, Bredesen DE. Sensory neuropath with low-dose pyridoxine. Neurology
1985;35:1466–68.
14. Schaumburg H, Kaplan J, Windebank A, et al. Sensory neuropathy from pyridoxine abuse. N
Engl J Med 1983;309(8):445–48.
References (continued):
15. Scharrer A, Ober M. Anthocyanosides in the treatment of retinopathies. Klin
Monatsblatt Augenheilk 1981;178:386–89.
16. Lanthony P, Cosson JP. The course of color vision in early diabetic retinopathy
treated with Ginkgo biloba extract. A preliminary double-blind versus placebo study. J
Fr Ophtalmol 1988;11:671–74 (in French).
17. Aida K, Tawata M, Shindo H, et al. Isoliquiritigenin: A new aldose reductase inhibitor
from glycyrrhizae radix. Planta Med 1990;56:215–21.
Copyright © 1998 Virtual Health, LLC
It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over-the-counter medication is also available. Consult your physician, nutritionally-oriented health care practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications.The information presented in HealthNotes Online is for informational purposes only.