Basic pentcam for refractive surgery decision
•Download as PPTX, PDF•
3 likes•336 views
corneal refractive surgery decision
Recommended
More Related Content
What's hot
What's hot (20)
Similar to Basic pentcam for refractive surgery decision
Similar to Basic pentcam for refractive surgery decision (20)
More from Samhaa Mohammed
More from Samhaa Mohammed (20)
Recently uploaded
Recently uploaded (20)
Basic pentcam for 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. 17th century ---- marble reflection at cornea. 2. Placido disc reflection (white & black rings on the convex surface of cornea. 3. Placido based topography 4. Tomography (pentcam)---- scanning slit beam
- 4. Uses Rfractive surgery KC Post surgical astigmatis m, selective suture removal Surface planning in astigmatis m (LRI Effect of OSD (pterygium, dermoid, scar) CL fitting Incision placement ICR Placement
- 6. Placido disc, Topograpgy • Kmax > 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.
- 8. Corneal tomography basic principles 1. Placido disc reflection. 2. Scanning slit. 3. Scheimpflug photography.
- 9. Tomography (pentcam) reading 1. Quality specification(QS) 2. Kmax 3. Thinnest location 4. Y coordinate of thinnest location 5. Topographic astigmatism 6. Q value 7. Sagital curvature 8. Corneal thickness 9. Anterior elevation 10. Posterior elevation 11. Corneal thickness profile 12. Inter eye difference
- 10. Tomography (pentcam) 1. 4 refractive maps (axial curvature, thickness, Ant. elevation, post. elevation) • Axial curvature: kmax, I/S value, Q value • Thickness: thinnest location, apex pachymetry, thinnest location @Y coordinate 2. Belin Ambrosio
- 24. Pattern Points 4 3 2 1 0 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
- 25. 1 high risk or 2 moderate X
- 27. • > 34D for myopic ablation • < 49 for hyperopic •→ (SE, each 1 D myopia decrease Km by 0.8, &hyperopia increase by 1.2) • Kf in myope& Kmax in hyperope < 47 → • →إزاي هنحسبها • Cylinder (look at Ks in myopic astig. & Kf for hyperopic astig.) • Sphere (myopia flat all KS, hyperope the reverse) • Lasik (PTA<40%) • PRK > 400 • → (total refraction, AD according to Munnerlyn formula ) • Lasik >500 → • PRK > 470 → • →إزاي هنحسبها Preop. Thickness Postop. Thickness Postop. K reading Preop. K reading
- 29. Female pt 27 y OD (0.16 _ 1.0 ) with-2.00D, OS (0.1 _1.0) with – 3.00D. Case 1
- 30. Female pt 27 y OD (0.16 _ 1.0 ) with-2.00D, OS (0.1 _1.0) with – 3.00D. Case 1 Decision ?
- 31. Female pt 27 y OD (0.16 _ 1.0 ) with-2.00D, OS (0.1 _1.0) with – 3.00D. Case 1
- 32. Female pt 27 y OD (0.16 _ 1.0 ) with-2.00D, OS (0.1 _1.0) with – 3.00D. Case 1
- 33. 1 high risk or 2 moderate X
- 34. Pattern Points 4 3 2 1 0 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
- 36. • > 34D for myopic ablation • < 49 for hyperopic • (SE, each 1 D myopia decrease Km by 0.8, &hyperopia increase by 1.2) • Kf in myope& Kmax in hyperope < 47 → • →إزاي هنحسبها • Cylinder (look at Ks in myopic astig. & Kf for hyperopic astig.) • Sphere (myopia flat all KS, hyperope the reverse) • Lasik (PTA<40%) • PRK > 400 • (total refraction, AD according to Munnerlyn formula ) • Lasik >500 → • PRK > 470 → • →إزاي هنحسبها Preop. Thickness Postop. Thickness Postop. K reading Preop. K reading
- 37. 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
- 38. CI Cornea (KC) ABSOLUTE Untreated OSD (OCP. Post blepharitis, KCS) Pregnancy, lactation Significant cat., tear, RD. Uncontrolled glaucoma Unrealistic expectation Systemic diseases (DM, autoimmune dis.) Unstable, Outside range EOR Steroid responder Drugs affect healing (retinoids, amiodarone, antihistaminic,colchicine) Corneal diseeases (flat, dry, hx of herpes, recent surgery)
- 39. 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
- 40. 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 ?
- 41. Female pt 27 y OD (0.16 _ 0.9 ) with-16.00D, OS (0.1 _1.0) with – 7.00D. Case 4
- 42. Female pt 27 y OD (0.16 _ 0.9 ) with-16.00D, OS (0.1 _1.0) with – 7.00D. Case 4 Decision ?
- 43. Female 25y OD (0.2 _ 1.0) with-2.00D/-0.75*150, OS (0.1 _1.0) with - 2.75. Case 5 Decision ?
- 45. Age Range of refractive error Ocular & systemic evaluation 12 points and score Calculate postop thickness, k reading. (Others) Angle kappa Pupil offset AC depth (phakic iol) Do not forget
- 46. Tomography (pentcam) reading 1. Quality specification(QS) 2. Kmax 3. Thinnest location 4. Y coordinate of thinnest location 5. Topographic astigmatism 6. Q value 7. Sagital curvature 8. Corneal thickness 9. Anterior elevation 10. Posterior elevation 11. Corneal thickness profile 12. Inter eye difference
- 47. Tomography (pentcam) 1. 4 refractive maps (axial curvature, thickness, Ant. elevation, post. elevation) • Axial curvature: kmax, I/S value, Q value • Thickness: thinnest location, apex pachymetry, thinnest location @Y coordinate 2. Belin Ambrosio
- 48. Pattern Points 4 3 2 1 0 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
- 49. 1 high risk or 2 moderate X
- 51. • > 34D for myopic ablation • < 49 for hyperopic • (SE, each 1 D myopia decrease Km by 0.8, &hyperopia increase by 1.2) • Kf in myope& Kmax in hyperope < 47 → • →إزاي هنحسبها • Cylinder (look at Ks in myopic astig. & Kf for hyperopic astig.) • Sphere (myopia flat all KS, hyperope the reverse) • Lasik (PTA<40%) • PRK > 400 • (total refraction, AD according to Munnerlyn formula ) • Lasik >500 → • PRK > 470 → • →إزاي هنحسبها Preop. Thickness Postop. Thickness Postop. K reading Preop. K reading
Editor's Notes
- Rt PKP
- Rt PKP
- Rt PKP
- Rt PKP
- Rt PKP
- Rt PKP
- Rt PKP