Anatomy of cornea
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Transcript of Anatomy of cornea
Anatomy of cornea
Presented by:- Prachee Shree
2nd sem, 1st year
B.optom
Instructor:- moutushi madam
What is CORNEA..?
Avscular tissueTransparentImportant OpticalElement (+43.27D)Very sensitive
Corneal Dimensions
HVID=11.7mmVVID=10.6mmArea=1.3 cm sq.Saggital depth=2.6mm(avg.)Refractive index=1.376Power :-anterior(+48D) :-posterior(-5D)Thickness: central- 0.52mm
peripheral- 0.67mmRadius of curvature:
anterior surface:-7.8mmposterior surface:-6.2-6.8mm
Corneal Dimensions
Corneal Composition• 78% water
• 15% collagen
• 5% other parts
• 1% GAGs
• Epithelium » 10% of cornea’s wet weight
Layers of CORNEA
Corneal EpitheliumBowman’s MembraneCorneal StromaDescemet’s MembraneCorneal Endothelium
Corneal EpitheliumOuter most layer50 microns thick3 types of cellCan regenerateProvides smooth surface
EPITHELIUM CELLS SURFACE CELLS (2 Layers)• Thin• Squamous• Overlapping polygonal cells
WING CELLS (2 Layers)• Overlays Basal layer• ‘Wings’ protruding into space between domes of
basal cells BASAL CELLS
• Deepest• Columnar• Hemispherical anterior surface
Bowman’s Membrane
Acellular12 microns thick (8-14µm)Thin, Elastic MembraneDoes not regenerate and is
replaced by Opaque Scar Tissue
Corneal Stroma0.50 µm thick Composed of Collagen fibreTough and Hard to puncture or
cut2-3 % Keratocytes and 1 % GAGs200-250 Lamellae superimposed
on one another
Descemet’s Membrane
10 microns thickHighly elastic AcellularProduced by EndotheliumCan regenerate if destroyed
Corneal Endothelium Innermost layer5 lakhs polygonal cellsReceives nutrients from Aqueous
HumourDegenerate & Die but can’t
regenerateMost important for corneal
transparency If damaged causes, Corneal
hydration & oedema occurs
Specular reflection
Supply to cornea
Blood supply
Supplied by conjunctival & episcleral capillary network in the limbal region
Trigeminal nerve
Ophthalmic division
Nasociliary nerve
Long ciliary nerve conjunctival nerve
Pericorneal plexus70-80 nerves innervates
Stromal plexus
Sub epithelial plexusLooses sheath of shwann
Supplies all over epithelial layers
Nerve supply
Functioning of cornea
Main refracting materialActs as protective layer
1
Any
queries…??????
?
1.Substantia propria is another name of which layer of cornea….?
2.Increase in size of corneal endothelial cells is called_______________.
questions for you
CONTD…
3. Any deformity in regular polygonality (shape) of corneal endothelial cell is said to be_________________.
4. Which corneal layer is absent in carnivores animal…?
Contd…
5. What is the main source of oxygen supply in cornea…?
Thank you for all
Best wishes for upcoming exams