Week 1- Approach to Diseases of the Lens Flashcards
(41 cards)
What are the three main components of the lens
capsule lens epithelium lens fibers
What suspends the lens in the eye
zonular fibers from the ciliary body
Is the lens vascular or avascular
avascular
How does the lens receive nutrients
from the aqueous humor
Does nuclear sclerosis affect vision
no
What causes nuclear sclerosis
increased density of secondary lens fibers with age
How can you distinguish cataract from nuclear sclerosis
retroillumination shows full tapetal reflection in sclerosis
What is a cataract
loss of transparency of the lens
How does a cataract appear on retroillumination
black shadow against tapetal reflection
What are the common causes of cataract
uveitis glaucoma PRA diabetes
What causes lens opacity in cataracts
disruption of lens fibers increased hydration protein deposition
What is the most common endocrine cause of cataracts
diabetes mellitus
Is cataract progression faster than nuclear sclerosis
yes
What are primary cataracts
inherited cataracts in certain breeds
What are secondary causes of cataract
PRA uveitis glaucoma trauma metabolic dietary toxic
What are the stages of cataract based on opacity
incipient immature mature hypermature morganian
What is an immature cataract
partial lens opacity with some vision retained
What is a mature cataract
complete lens opacity causing blindness
Why does diabetes cause cataracts
hyperglycemia leads to sorbitol accumulation causing osmotic lens swelling
Does cataract surgery restore vision
yes if retina is functional
What is lens induced uveitis
inflammation caused by leakage of lens proteins
When should you assume LIU is present
in all mature or hypermature cataracts
How is LIU treated
topical and systemic anti-inflammatories
What is the only current treatment for cataracts
surgical removal
