Cornea

Question 1

Changes in Shape and Optical Properties:

Answer 1

1) Steepening of curvature and a shift from WTR to ATR.
2) Causes refractive change in elderly and difficulty with certain letters.
3) Transparency is unaffected in central cornea in absence of scar or degeneration.
4) Collagen intramolecular and interfibrillar spacing increases; due to increased protein glycation.
5) Increased thickness of Descemet’s membrane

Question 2

Avascular Structure

Answer 2

Absence of blood vessels

Question 3

Keratocytes

Answer 3

Fibroblasts

Are mesenchymal-derived cells of the Corneal Stroma.

These cells are normally quiescent, but they can readily respond and transition into repair phenotypes following injury.

Question 4

Mesenchymal Cells

Answer 4

Unspecialised cells that can differentiate and specialise into Keratocytes.

Question 5

Pluripotent

Answer 5

Pluripotent cells can give rise to all of the cell types that make up the body; embryonic stem cells are considered pluripotent.

Question 6

Fluorescein staining of a dendritic ulcer, pathognomonic for herpetic keratitis.

Answer 6

This is a type of corneal ulcer where steroids are absolutely contraindicated due to the risk of worsening the infection.

Question 7

Desquamation of corneal epithelium

Answer 7

Shedding the epithelial cells