Flashcards in Ophthalmology Deck (75)
What are the risk factors for developing cataracts?
Topical or systemic steroids
What is glycation?
The binding of glucose to proteins which results in free radical production
Diabetes increases what enzyme that eventually leads to the production of cataracts?
What is aldose reductase?
It is an enzyme that catalyze one of the steps in the polyol (a sugar alcohol) pathway that is responsible for the formation of fructose from glucose
How does diabetes lead to cataracts?
Aldose reductase levels increase with an increase in glucose in tissues that are not insulin sensitive, including the lens, peripheral nerves and glomeruli. Aldose reductase reduces glucose to its alcohol. The lens is relatively impermeable to sugar alcohols. The lens imbibes water, causing an osmotic imbalance. Eventually, increased sodium and decrease potassium levels and decreased final levels lead to cataract formation.
What flavonoid can slow the progression of diabetes-related cataracts?
Quercetin. It can inhibit aldos reductase
Altered color vision
Fells like you are looking through a piece of clouded glass
Increased sensitivity to bright lights
Increased blurred vision
Need brighter illumination (trouble seeing in the dark)
Diplopia when looking out of one eye
Vision that is brighter in one eye than the other
Nutrients that are protective against cataracts
Vitamins A, C & E (antioxidants)
Carnosine is formed by the combination of what 2 amino acids?
How does carnosine protect against cataract formation?
It is an antioxidant
It binds metal ions that cause tissue damage
It blocks the aging effects of glycation by competing with proteins for the binding sites they would occupy on sugar molecules
How does carnosine protect against dementia?
It inhibits beta amyloid toxicity
It chelates copper and zinc
What is the oral dose of carnosine?
1000-2000 mg per day
Use caution of supplementing carnosine in what medical conditions?
Liver or kidney disease
Carnosine used as eye drops has what effect on DNA?
It prevents DNA strand breaks induced by UV radiation
It enhances DNA repair
Treatment for dry eyes
EPA and DHA
Diseases that carnosine is used to treat
What AAs is glutathione made of?
How does glutathione protect against cataracts?
It functions to protect the structural proteins and enzymes needed for the maintenance of lens flexibility and clarity against free radical production
Loss of glutathione in the eye leads to what?
Glycation and thus cataracts
At what age does glutathione production in the body start to decrease?
Why can't glutathione be taken by mouth?
Digestive enzymes break it down. It can be take as NAC
What are the nutrients that can increase glutathione?
What can decrease glutathione
Processed meats containing nitrites or nitrates
Food sources of glutathione
What is the typical dose range for NAC?
500 - 3000 mg per day
Why should NAC be given with vitamin C?
To prevent kidney stone formation
If taking NAC for a long duration, what should be supplemented
Zinc and copper. NAC can bind them
How does glutathione affect the immune system?
It stimulates IL-1 and IL-2 production
What vitamins does glutathione help to recycle?
Vitamins C and E