Corneal Repair Flashcards Preview

Ocular Physiology > Corneal Repair > Flashcards

Flashcards in Corneal Repair Deck (27):
1

Integrins

connects cells and extracellular matrix
forms intercellular junctions
sense change in extracellular environment

2

Cytokines

fascilitate cellular communication between cells and surrounding tissues
control growth of corneal cells

3

Growth Factors

promote proliferation of corneal cells
starts migration of cells
maintains transparency

4

Layers of Epithelium

Surface- 2
Wing- 2-3
Basal- 1

5

Layer for Epithelial Cell Replication

Basal Layer

6

How long is the cell turnover of the epithelium?

7 days

7

Initiate repair of corneal epithelium

growth factors and cytokines
released from damaged cells

8

Change in cytoskeleton during healing

cell shape changes
cells at wound edges develop membrane extensions
cells migrate to cover wound

9

Cell Migration requires....

hemidesmosomes
cytoskeleton structure
cell to matrix adhesion
preserves integrity of epithelium

10

Adhesion Molecules

allow for epithelium to stick to Bowman's
pulls cells forward to cover wound

11

Prevents Epithelial Hyperplasia during wound healing

apoptosis

12

Healing time of a small lesion

24 - 48 hrs

13

Healing time if basement membrane is damaged

several months

14

Recurrent Corneal Erosion

epithelium sloughs off
from poor adhesion b/t epithelium and basement membrane or b/t BM and stroma

15

Recurrent Corneal Erosion occurs when?

after incomplete healing of abrasion
epithelial basement membrane dystrophy

16

Treating Recurrent Corneal Erosion

artificial tears, antibiotics, bandage
anterior stromal micropuncture, superficial or phototherapeutic keratectomy

17

Bowman's Layer

acellular
composed of collagen
highly resistant to damage; does not regen

18

Replaces lost Bowman's cells

stromal scar tissue or epithelium

19

Stroma Composition

collagen fibrils
keratocytes
extracellular ground substance

20

Why is the stroma likely to scar?

new collagen fibers are larger and their organization is not as precise

21

Time frame to heal stroma

months
takes longer for new collagen to get to full strength

22

Descemet's Membrane

basement membrane of endothelium
made of collagen
produced constantly

23

Where does Descemet's membrane regenerate from?

stromal keratocytes and endothelium

24

Layers to Endothelium

1

25

Basal part of Endothelium faces.....

Descemet's

26

Apical part of Endothelium faces....

anterior chamber

27

Healing Endothelial Damage

neighboring cells enlarge and flatten to fill in space- loss of density
take polyhedral shape
increase # of ion pumps