ascorbic-acid and Blindness

Vision loss affects 37 million Americans older than 50 years and one in four who are older than 80 years. The U.S. Preventive Services Task Force concludes that current evidence is insufficient to assess the balance of benefits and harms of screening for impaired visual acuity in adults older than 65 years. However, family physicians play a critical role in identifying persons who are at risk of vision loss, counseling patients, and referring patients for disease-specific treatment. The conditions that cause most cases of vision loss in older patients are age-related macular degeneration, glaucoma, ocular complications of diabetes mellitus, and age-related cataracts. Vitamin supplements can delay the progression of age-related macular degeneration. Intravitreal injection of a vascular endothelial growth factor inhibitor can preserve vision in the neovascular form of macular degeneration. Medicated eye drops reduce intraocular pressure and can delay the progression of vision loss in patients with glaucoma, but adherence to treatment is poor. Laser trabeculoplasty also lowers intraocular pressure and preserves vision in patients with primary open-angle glaucoma, but long-term studies are needed to identify who is most likely to benefit from surgery. Tight glycemic control in adults with diabetes slows the progression of diabetic retinopathy, but must be balanced against the risks of hypoglycemia and death in older adults. Fenofibrate also slows progression of diabetic retinopathy. Panretinal photocoagulation is the mainstay of treatment for diabetic retinopathy, whereas vascular endothelial growth factor inhibitors slow vision loss resulting from diabetic macular edema. Preoperative testing before cataract surgery does not improve outcomes and is not recommended.

Topics: Aged; Aged, 80 and over; Angiogenesis Inhibitors; Antihypertensive Agents; Ascorbic Acid; Bevacizumab; Blindness; Cataract; Cataract Extraction; Diabetic Retinopathy; Fenofibrate; Glaucoma; Humans; Hypolipidemic Agents; Intravitreal Injections; Light Coagulation; Macular Degeneration; Mass Screening; Practice Guidelines as Topic; Ranibizumab; Vision Disorders; Vision, Low; Vitamin E; Vitamins

Topics: Aged; Arthralgia; Ascorbic Acid; Blindness; Female; Fluorescein Angiography; Humans; Hyperoxaluria; Kidney Failure, Chronic; Renal Dialysis; Retinal Hemorrhage; Retinal Vessels; Tomography, Optical Coherence; Visual Acuity; Vomiting

OBJECTIVE--To evaluate the relationships between dietary intake of carotenoids and vitamins A, C, and E and the risk of neovascular age-related macular degeneration (AMD), the leading cause of irreversible blindness among adults. DESIGN--The multicenter Eye Disease Case-Control Study. SETTING--Five ophthalmology centers in the United States. PATIENTS--A total of 356 case subjects who were diagnosed with the advanced stage of AMD within 1 year prior to their enrollment, aged 55 to 80 years, and residing near a participating clinical center. The 520 control subjects were from the same geographic areas as case subjects, had other ocular diseases, and were frequency-matched to cases according to age and sex. MAIN OUTCOME MEASURES--The relative risk for AMD was estimated according to dietary indicators of antioxidant status, controlling for smoking and other risk factors, by using multiple logistic-regression analyses. RESULTS--A higher dietary intake of carotenoids was associated with a lower risk for AMD. Adjusting for other risk factors for AMD, we found that those in the highest quintile of carotenoid intake had a 43% lower risk for AMD compared with those in the lowest quintile (odds ratio, 0.57; 95% confidence interval, 0.35 to 0.92; P for trend = .02). Among the specific carotenoids, lutein and zeaxanthin, which are primarily obtained from dark green, leafy vegetables, were most strongly associated with a reduced risk for AMD (P for trend = .001). Several food items rich in carotenoids were inversely associated with AMD. In particular, a higher frequency of intake of spinach or collard greens was associated with a substantially lower risk for AMD (P for trend < .001). The intake of preformed vitamin A (retinol) was not appreciably related to AMD. Neither vitamin E nor total vitamin C consumption was associated with a statistically significant reduced risk for AMD, although a possibly lower risk for AMD was suggested among those with higher intake of vitamin C, particularly from foods. CONCLUSION--Increasing the consumption of foods rich in certain carotenoids, in particular dark green, leafy vegetables, may decrease the risk of developing advanced or exudative AMD, the most visually disabling form of macular degeneration among older people. These findings support the need for further studies of this relationship.

Topics: Aged; Aged, 80 and over; Aging; Antioxidants; Ascorbic Acid; Blindness; Carotenoids; Case-Control Studies; Data Collection; Diet; Eating; Female; Humans; Logistic Models; Macular Degeneration; Male; Middle Aged; Nutritional Physiological Phenomena; Risk Factors; Smoking; Vitamin A; Vitamin E

A young women was treated with intravenous quinine and chloramphenicol for suspected severe malaria and/or typhoid fever. On the second day of quinine therapy (after 2.25 g of quinine) she suddenly developed total bilateral loss of vision. Both drugs were stopped and cyclandelate therapy was started. She showed slight improvement in vision but on referral her visual acuity was limited to seeing waving hand movement only; visual fields were constricted and colour vision was absent. Both pupils were fixed and dilated. The fundi showed macular oedema and attenuated retinal arteries. She was treated with dexamethasone, cyclandelate, vitamin B complex and vitamin C. Colour vision was completely recovered after 5 days of treatment. Full recovery of the direct light reflex occurred after 10 days. Visual acuity improved slowly over a period of one month to 6/15 vision in both eyes. At this time macular oedema and retinal arteriolar attenuation were still present but less severe. In the context of this case report the condition of quinine blindness is briefly reviewed and the management discussed.

Topics: Adult; Ascorbic Acid; Blindness; Chloramphenicol; Cyclandelate; Dexamethasone; Drug Therapy, Combination; Female; Humans; Infusions, Intravenous; Malaria; Ophthalmoscopy; Quinine; Referral and Consultation; Typhoid Fever; Visual Acuity; Vitamin B Complex

Topics: Adult; Ascorbic Acid; Blindness; Diabetes Complications; Female; Hemosiderosis; Humans; Male; Middle Aged; Oxalates; Retina; Retinal Detachment; Retinal Diseases

Topics: Aminopyrine; Anti-Allergic Agents; Ascorbic Acid; Blindness; Common Cold; Double-Blind Method; Histamine H1 Antagonists; Humans; Rutin; Vasodilator Agents; Visually Impaired Persons