Cornea

Question 1

Corneal epithelial layers

Answer 1

Basal layer of columnar cells
Intermediate layer (interdigitating, wing or polygonal cells)
Outermost 3-4 layers of squamous cells poisoning tight junctions
Anterior plasma membrane of the most superficial layer of cells shows numerous microvilli and microplicae.

Question 2

Thinkess of coreal layers

Answer 2

Epith 50-60um
Epith BM 40-50um
Stroma 500um
Descement’s 12um

Question 3

Corneal wound healing

Answer 3

4-6h sloughing off necrotic tissue + retraction and rounding off cells at wound edge. (^synth of protein and actin filaments)
Within 2 hours hemidesmosmes disappear around wound edge.
PMN after 3h
Thinning , 2-3 layers >1 at the leading edge. (Folding of plasma membrane>cell migration)
Desmosomes intact so movement as a sheet.
Epith anchoring itself to the underlying connective tissue

Question 4

Stromal healing

Answer 4

Begings after complete epithelialisation
Fibroblast migrate to wound and lay down collagen matrix.
Remodeling

Question 5

Broad classification of corneal diseases

Answer 5

Ulcerative and non-ulcerative (infiltrative and non-infiltrative, infectious )