Corneal Diseases

Question 1

corneal endothelium function

Answer 1

5th layer of cornea

pumps fluid out of eye, removes water
(maintains transparency)

• cells do not regenerate (if swollen, patient cannot see)

Question 2

refracting power of cornea

Answer 2

+42 D

total power of eye is +60 D

Question 3

lamina cribosa

Answer 3

posterior pole in sclera for optic nerve exit

Question 4

causes of corneal diseases

Answer 4

infectious eye diseases
inflammatory eye diseases
trauma
corneal ulceration
corneal dystrophies - genetic defects

Question 5

corneal transplant

Answer 5

replaces diseased or scarred corneal tissue with healthy tissue from an organ donor

Question 6

issues with corneal transplants

Answer 6

shortage of donors

decrease in viability of cells after storage
- quality decreases w time

infection

graft rejection
- if cornea has blood vessels growing on it, will immediately reject (already transporting blood/immune cells to area)

Question 7

gene therapy

Answer 7

• replacing mutated gene that causes disease with healthy copy of gene
• inactivating mutated gene that is not functioning properly
• introducing new gene into body to help fight disease

advantages

• immune-privileged nature of cornea
• ease of visual monitoring
• noninvasive corneal assessment

Question 8

emerging approaches for treating corneal diseased

Answer 8

• gene therapy
• stem cells
• tissue engineering

Question 9

Why is cornea transparent?

Answer 9

• arrangement of corneal lamellae
• avascularity
• absence of lymph
• presence of nonmyelinated nerve fibers
• arrangement of epithelium

Question 10

corneal edema

Answer 10

opaque cornea (irregular)
- treatment = corneal transplant

Question 11

1, #2 causes of blindness

Answer 11

1. cataracts

2. glaucoma