Basic pentcam for refractive surgery decision

corneal refractive surgery decision

1. LASIK, PRK or not decision based on pentcam Samhaa Mohammed Abd Elmoneim Zagazig Ophthalmologic Hospital 2018 References Prof Mazen Sinjap books & videos Eyewiki website

2. Corneal tomography reading Investigative Dx for ectasia : 1. Keratometry (central 3mm) 2. Corneal topography 3. Tomography ( pentcam )

3. Corneal topography history 1. 17 th century ---- marble reflection at cornea. 2. P lacido disc reflection (white & black rings on the convex surface of cornea. 3. Placido based topography 4. T omography ( pentcam )---- scanning slit beam

4. Javal-Schoitz keratometer

5. Placido disc, Topograpgy K max > 47 D I/S value >1.5 D Skewing Pupil offset ( to avoid decentred ablation) Colours ( HOT , COLD ) The wider the rings , the flatter the cornea and the reverse.

6. Placido disc, Topograpgy

7. Corneal tomography basic principles 1. Placido disc reflection. 2. S canning slit. 3. S cheimpflug photography.

8. Tomography ( pentcam ) reading Quality specification(QS) K max Thinnest location Y coordinate of thinnest location Topographic astigmatism Q value Sagital curvature Corneal thickness Anterior elevation Posterior elevation Corneal thickness profile Inter eye difference

9. Tomography ( pentcam ) 4 refractive maps (axial curvature, thickness, Ant. elevation, post. e levation) Axial curvature: k max , I/S value, Q value Thickness: thinnest location, apex pachymetry , thinnest location @Y coordinate 2. Belin Ambrosio

10. Apply 12 points and train yourself

11. Tomography (normal pentcam )

12. Tomography ( pentcam )

13. Tomography ( pentcam )

14. Tomography ( pentcam )

15. Tomography ( pentcam )

16. Tomography ( pentcam )

17. Tomography ( pentcam )

18. Tomography ( pentcam )

19. Tomography ( pentcam )

20. Tomography ( pentcam )

21. 3. Tomography ( pentcam )

22. Calculations and Scoring for decision

23. Pattern Points 4 3 2 1 Topography Abnormal topography Inf steepening/ SRA Assymetrical bowtie Normal symmetrical bowtie RSB < 240 241 _ 259 260 _ 279 280 _ 299 >300 Age 18 _ 21 22 _ 25 25 _ 29 >30 CCT <450 451_480 481_ 510 >510 MRSE > -14 -12_ -14 -10 _ -12 -8 _ -10 < -8 Total risk score Relative risk Recommendation 0 _ 2 Low Lasik or PRK 3 Moderate Perform with caution 4 High Do not perform

24. 1 high risk or 2 moderate X

25. Apply on each case

26. Female pt 27 y OD (0.16 _ 1.0 ) with-2.00D, OS (0.1 _1.0) with – 3.00D. Case 1

27. Female pt 27 y OD (0.16 _ 1.0 ) with-2.00D, OS (0.1 _1.0) with – 3.00D. Case 1 Decision ?

28. Female pt 27 y OD (0.16 _ 1.0 ) with-2.00D, OS (0.1 _1.0) with – 3.00D. Case 1

29. Female pt 27 y OD (0.16 _ 1.0 ) with-2.00D, OS (0.1 _1.0) with – 3.00D. Case 1

30. 1 high risk or 2 moderate X

31. Pattern Points 4 3 2 1 Topography Abnormal topography Inf steepening/ SRA Assymetrical bowtie Normal symmetrical bowtie RSB < 240 241 _ 259 260 _ 279 280 _ 299 >300 Age 18 _ 21 22 _ 25 25 _ 29 >30 CCT <450 451_480 481_ 510 >510 MRSE > -14 -12_ -14 -10 _ -12 -8 _ -10 < -8 Total risk score Relative risk Recommendation 0 _ 2 Low Lasik or PRK 3 Moderate Perform with caution 4 High Do not perform

32. Female pt 27 y OD (0.16 _ 1.0 ) with-2.00D, OS (0.1 _1.0) with – 3.00D, she is on chloroquine for RA . Case 2

33. Male pt 29 y OD (0.16 _ 0.6) with-1.00D/-2.75*150, OS (0.1 _0.6) with -0.75/ – 3.50D *25. Case 3

34. Male pt 29 y OD (0.16 _ 0.6) with-1.00D/-2.75*150, OS (0.1 _0.6) with -0.75/ – 3.50D *25. Case 3 Decision ?

35. Female pt 27 y OD (0.16 _ 0.9 ) with-16.00D, OS (0.1 _1.0) with – 7.00D. Case 4

36. Female pt 27 y OD (0.16 _ 0.9 ) with -16.00D , OS (0.1 _1.0) with – 7.00D. Case 4 Decision ?

37. Female 25y OD (0.2 _ 1.0) with-2.00D/-0.75*150, OS (0.1 _1.0) with -2.75. Case 5 Decision?

38. Do not be confused !! Practice Copy the following basic data with you. Continue reading and adding more tips through your practice

39. Do not forget

40. Tomography ( pentcam ) reading Quality specification(QS) K max Thinnest location Y coordinate of thinnest location Topographic astigmatism Q value Sagital curvature Corneal thickness Anterior elevation Posterior elevation Corneal thickness profile Inter eye difference

41. Tomography ( pentcam ) 4 refractive maps (axial curvature, thickness, Ant. elevation, post. e levation) Axial curvature: k max , I/S value, Q value Thickness: thinnest location, apex pachymetry , thinnest location @Y coordinate 2. Belin Ambrosio

42. Pattern Points 4 3 2 1 Topography Abnormal topography Inf steepening/ SRA Asymmetric bowtie Normal symmetrical bowtie RSB < 240 241 _ 259 260 _ 279 280 _ 299 >300 Age 18 _ 21 22 _ 25 25 _ 29 >30 CCT <450 451_480 481_ 510 >510 MRSE > -14 -12_ -14 -10 _ -12 -8 _ -10 < -8 Total risk score Relative risk Recommendation 0 _ 2 Low Lasik or PRK 3 Moderate Perform with caution 4 High Do not perform

43. 1 high risk or 2 moderate X