10 - disorders of the lens

Question 1

Answer 1

Question 2

lens aging (nuclear sclerosis)

1. lens fiber produced throughout life -> central portions become compressed -> hardening of lens nucleus

Question 3

what are cataracts?

Answer 3

any opacity within the lens

(can be congenital, juvenile (young dogs), senile (6 yrs or older)

Question 4

(cataracts - give name for each)

1. less than 15% of lens opaque
2. tapetal reflection still visible
3. solid opacity of the lens and absence of a tapetal reflection
4. liquefaction of lens cortex

Answer 4

1. incipient
2. immature
3. intumescent
4. hypermature

Question 5

(cataracts - location within the lens)

Question 6

(cataracts - causes)

1. is it genetic/heritable?
2. what metabolic dz causes?

3.

Answer 6

1. yes - one of the most common causes in dogs
2. DM

Question 7

treatment for cataracts?

Answer 7

surgery!

Question 8

(abnormalities of the zonular fibers - lens displacement)

(degree of dislocation)

1. lens remains in the patellar fossa behind the iris = ?
2. complete diplacement of the lens from teh patellar fossa
3. anterior luxation predisposes to what?

Answer 8

1. subluxation
2. luxation
3. glaucoma

Question 9

(abnormalities of the zonular fibers - lens displacement)

anterior (anterior to plane of iris) or posterior (into viterous cavity)

Question 10

(abnormalities of the zonular fibers - lens displacement)

(primary causes)

1. due to degeneration of what?
2. predisposed breeds?

Answer 10

1. zonular fibers
2. terriers

Question 11

(abnormalities of the zonular fibers - lens displacement)

can also be secondary to other ocular disease

Question 12

(abnormalities of the zonular fibers - lens displacement)

tx?

Answer 12

intracapsular lens extraction