Systemic Diseases Flashcards
some systemic diseases that affect the eye
allergic diseases skin and mucous diseases viral, bacterial infections diabetes mellitus hypertension sickle cell arteriosclerosis
why is ophthalmoscopy important?
only means of directly inspecting arteries, veins, and central nervous system in an intact, living person
- noninvasive
normal ocular fundus (appearance)
- back of eye
arteries = lighter red veins = darker red
diabetes facts
15 million people in the US have diabetes
diabetic retinopathy = leading cause of new blindness in persons aged 25-74 in US
diagnosis of diabetes
symptoms:
- polyuria - excessive urination
- polydipsia - excessive drinking
- polyphagia - excessive eating
sugar is not being processed (still in blood)
- body is starving, damages capillaries
if pancreas is not functioning, beta cells produce little or no insulin
diabetes mellitus I & II
type 1 - juvenile diabetes
- pancreas produces NO insulin
type 2 - working pancreas but not enough insulin produced
- usually overweight patients (body can’t keep up with sugar intake)
elevated blood glucose
when there is elevated blood glucose, a glycosylation reaction occurs between the sugar and proteins in vessel wall
- over time, causes capillary thickening (loss of pericyte and breakdown of vessel wall)
pericyte (like hand) = opens or closes capillaries so blood flows to other organs
- extremely sensitive to glucose level in capillary
- does not regenerate (small role leaks blood, gets larger over time)
- after years of diabetes, does not get enough blood, oxygen to eye
- neural tissue (connected to brain); does not regenerate
proliferative diabetic retinopathy (image)
- more dots and hemorrhages
- spots = loss of vision in area (dying off)
(hypoxia = oxygen not getting to area)
neovascularization = growth of abnormal blood vessels
diabetic cataract
fluctuation of sugar levels induces cataracts 20 years younger
- fibers are misaligned = loss of clarity
- fluid leaks into eye - disrupts vision/clarity
hypertension statistics
> 140/90
4th largest mortality risk
- no pain, symptoms
AV nicking
artery is on top of vein
- high pressure in artery, vein is compressed, blood backs up into eye (decreased vision)
macular star
proteins/lipids leak and collect over macula
cotton-wool spots - micro-infarcts
infarct = lack of oxygen
- area swells and dies off (turns white)
arteriosclerosis
hardening of arteries (buildup of lipids and cholesterol)
- carotid artery bifocates/splits:
internal - goes to brain
external - feeds eye
Grave’s Disease
body attacks itself at thyroid gland and eye muscles
- eye muscles grow, bulge forward (can’t move easily) = double vision
