Cornea

Cornea

• 45 - 50 D ,
• 1.37 RI , 
• 10.5 - 11 mm Diameter

Megalocornea - >13

Microcornea - <10

Shape - Asymmetrical

5 Layers - 

• Epithelial (Proliferates)
• Bowman's
• Stroma
• Descemet's membrane
• Endothelium (NEVER DIVIDES) - Corneal Dehydration because of :

                                                 1. Na K ATPase pump - therefore does not allow hydration

                                                 2. also it is barrier

-----------------------------------------------------------------------------------------------------------
Endothelial Cells - approx. 2500 cells/mm sq
When dies - there is compensation of space and function.
but if <500 cell/mm sq - then there will be no compensation -- i.e Corneal Decompensation -- Later leads to Bullous Keratopathy

Endothelium is metabolically most active.


-----------------------------------------------------------------------------------------------------------

Contact Lens -- Decrease oxygen --- therefore decrease glucose utilization.