Nutritional Factors in Cataract

Abstract

Age-related cataract is a condition characterized by multiple mechanisms and multiple risk factors. The mechanisms that bring about a loss in transparency include oxidation, osmotic stress, and chemical adduct formation. Risk factors for cataract include diabetes, radiation (ultraviolet B, x-ray), certain pharmaceutical substances, certain nutritional states, and possibly acute episodes of dehydration. Interaction occurs between and among mechanistic factors and risk factors. Thus nutrition must be considered as one part of a tapestry of intertwined events and responses. Certain experimental models for nutritional cataract have been useful for study of the cataractogenic process but are probably not important factors in the human disease. Little current evidence supports significant roles in human senile cataract for imbalances of tryptophan or other amino acids, deficiencies of calcium or selenium, or excessive intake of selenium. Overconsumption of galactose is likely to be hazardous only in subjects with genetic inability to metabolize this sugar. Vitamins with antioxidant potential (riboflavin, vitamin E, vitamin C, carotenoids) deserve further research scrutiny to ascertain their significance in cataract etiology. Excessive caloric intake needs to receive added emphasis as a factor contributing to cataract. Diabetes increases the likelihood of cataract three- to four-fold. Obesity, defined as more than 20% overweight, is considered a major risk factor for non-insulin-dependent, or type II, diabetes (69, 73). Weight control can be recommended as a prudent, safe, economic, and effective means of lowering risk probability for diabetes and the associated complication of cataract.

Ditopic Complexation of Selenite Anions or Calcium Cations by Pirenoxine: An Implication for Anti-Cataractogenesis

“…Although the exact causes of cataracts remain vague, protein aggregation and osmotic damage leading to a loss of transparency appear to be the main contributors to this disease. 47 Changes in hydration or electrolyte content can also lead to protein aggregation. Additionally, chemical modifications or oxidations of lens proteins may contribute to the emergence of opacities.…”

Comparative study of serum Na+ and K+ levels in senile cataract patients and normal individuals

“…Up to 50 millions in the world suffer from age-related cataract 6-7 and its prevalence in developing countries is much more than the developed ones 8. Annual new cases of cataract in India is 4 millions 7, and more than one million cataract surgeries are done annually in United States of America, although the accurate number of those suffering from cataract might be unknown 5.…”

Chronic carbon monoxide poisoning resulting in bilateral cataracts and a cystic globus pallidus lesion

“…The lengthy nature of CO exposure together with multisystem involvement is highly suggestive of CO as the causative factor of cataract in this case. Possible mechanisms include increased oxidative stress leading to precipitation of lens proteins 13–15. Evidence in keeping with this is that smokers are known to have low plasma antioxidant levels and the relative risk of cataract formation reduces correlates inversely with dietary antioxidant intake 1 2.…”