The document discusses the five layers of the cornea - epithelium, Bowman's membrane, stroma, Descemet's membrane, and endothelium. It describes the function of each layer. It also discusses corneal topography, which provides a 3D view of the cornea and is used to diagnose corneal conditions. Key measurements from topography include K readings to determine astigmatism and pachemetry readings to measure corneal thickness. Abnormal topography findings can indicate conditions like keratoconus, where the cornea protrudes in a cone shape. The document demonstrates how to properly perform corneal topography and pachymetry ultrasound scans.

1. Cornea and Cornea TopographyWith Bausch and Lomb OrbscanIIz

2. 5 Layers of CorneaEpitheliumBowman’s MembraneStromaDescemet’s MembraneEndothelium

3. EpitheliumProvides Protection Provides a smooth surface so that nutrients and oxygen can transfer to the cornea.A lot of nerve endings

4. Bowman’s MembraneComposed of strong collagen tissueHelps to maintain the cornea’s shapeHelps anchors down the epithelium

5. StromaContains mostly of water and proteinThe alignment of collagen fibers help the cornea retain its clarity.

6. Descemet’s MembraneFilters out infections and disease

7. Helps with the stroma in maintaining the rigid shape of the cornea EndotheliumHelps pumps fluid out of the Stroma

8. Corneal Topography3D view of CorneaAids in diagnosis various cornea conditions and diseaseUsed in Laser Refractive Surgeries

9. K ReadingsMeasures is DioptersK< 41D is consider flatK>46D is consider SteepK>41 but <46 is consider averageImportant in determining LASIK K readings are also used in IOL Master to calculate IOL’s

10. Anterior Map

11. Posterior Map

12. Keratometric Map

13. Regular Astigmatism

14. Irregular Astigmatism

15. Pachemetry Map

16. Normal Topography

17. Abnormal Topography

18. Abnormal Topography

19. KeratoconusAbnormal Cornea condition where the cornea protrudes out more; Instead of a Dome like Figure, it becomes like a coneDistorts and reduces visionUsually bilaterally but asymmetrical Usually Myopic with large amounts of Irregular astigmatismNo corneal refractive surgeries can be doneAs the cornea steepens, the cornea pachemtry gets thinner

20. Keratoconus cont…

21. 3D Anterior Map of KC

22. 3D Posterior Map of KC

23. How to take TopographiesHave the patient sit at a comfortable levelInform the patient on what test you are doingTry to have a good tear filmLet the patient know they cannot move doing this test

24. Demonstration of Topography

25. How to take Pachs with UltrasoundAlways have pt look at a fixation pointCarefully touch the central cornea with tipTry not to indent the corneaAlways get a consistent reading

26. Demonstration of US Pachs

27. Keep in your headConsistency is the answerKnowing what is normal and abnormalGood tear filmBeing comfortable with the machine will make the patient more comfortable with youWhen in doubt always ask