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The Orthokeratolgy Company

The Orthokeratolgy Company. GOV & VIPOK Updates. The Ideal Patient. The Ideal Ortho-K Patient. Suitable candidates for Ortho-K Age of Patient – older than 6 years Spherical refractive power +5D to -10.00D Cylindrical refractive power: -1.50D or less W-T-Rule astigmatism

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The Orthokeratolgy Company

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  1. The Orthokeratolgy Company GOV & VIPOK Updates

  2. The Ideal Patient

  3. The Ideal Ortho-K Patient Suitable candidates for Ortho-K • Age of Patient – older than 6 years • Spherical refractive power +5D to -10.00D • Cylindrical refractive power: • -1.50D or less W-T-Rule astigmatism • -0.75D or less A-T-Rule astigmatism • Children with progressive myopia • Patients free of corneal pathology • Patients that are committed to initial and ongoing cost of treatment

  4. Screen for a healthy cornea • Don’t fit when: • Cornea is distorted • Eye Rubbing (treat allergies & habit) • Soft or RGP imprints (allow rehabilitation) • Corneal abnormalities • Irregular corneal astigmatism • Keratoconus • Pellucid Marginal Degeneration • Lid or corneal pathology is present

  5. Topographer Calibrate Topographer!

  6. Topographer • Accuracy depends on: • Software algorithms used to reconstruct corneal shape (update software) • Stability of the patient’s tear film during capture (use wetting drops) • Head position & movement during capture • Lid aperture (open eyes) • Number of reading done to get statistically significant accuracy • Take multiple readings • Omit high & low values

  7. Cylinder Rules • <1.50D W-T-R • <0.75D A-T-R • Cyl ≤ ½Sph • -0.50 / -1.50 – Problem • -3.00/-1.00 – Fine

  8. Fitting the Ortho-K Lens

  9. Empirical fitting vs.SystemisedFitting Systems

  10. Empirical Fitting Systems • Corneal information is given to lab • Lab designs lens • Lens works • Or it doesn’t!

  11. Systemised Fitting Systems General fitting process: • Initial lens is chosen from chart • Fit with diagnostic trial lenses and evaluate NaFL pattern – Look for Bull’s eye pattern • Initial lens should not be too flat and should move 1 – 2mm on blink • Evaluate after 30 min using the topographer • Does the Px show a central flattening effect ?

  12. Systemised Fitting Systems General fitting process • If diagnostic lens looks acceptable, allow Px to wear overnight and evaluate the next morning • If the lens is too tight or too loose a different lens can be chosen from trial set and refitted

  13. Systemised Fitting Systems Lens adaptation and follow-up • Centration is critical. • Movement: 1 – 2 mm with blinking. • Flourescein pattern: Bulls eye pattern.

  14. Fitting the Ortho-K Lens Flourescein patterns:

  15. The Orthokeratology Company • GOV – Global Ortho-K Vision • Vipok II – Non Conformed <-5.00D • XMJ– Conformed <-5.00D • XM – Conformed >5.00 <10.00D • H – Hyperopia • HP – HyperopiaPresbyopia • MP – MiopicPresbyopia • Post Lasik & Keratoconus • Website (Plan Date Jan 2008) • Ordering • Blog • Px & Prac Education

  16. The GOV System • Advanced inventory system • Multi-curve aspheric conformed Reverse Geometry Lenses • Simple method for myopia & hyperopia correction • You are in control of the lens fit – not laboratories • Correct from +5.00D to -10.00D GOAL A simple method to start Orthokeratology allowing for growth into fitting higher powers with the confidence that there is a support group.

  17. Benifits Simple effective system • You choose the appropriate lens and make changes • Immediate dispensing – (full trial set) • Efficient and effective method to increase turnover • Develop a specialty Ortho-k practice • Confidently fit with GOV support

  18. GOVTMlens details • Base curve • Hydraulic massage to central cornea • Conformed fitting curve (1st reverse zone) • Space for tear circulation & tissue molding • Alignment curve (2nd reverse) • Peripheral compression & centration • Peripheral curve • Tear reservoir for cornea wetting

  19. Predetermined OAD (lens size) • OADs of trial lenses are predetermined • Flatter Ks accompany larger corneas • Steeper Ks accompany smaller corneas

  20. Fitting GOVTM Lenses • External ocular exam • Measure refraction, keratometry & HVID • Select K-code by Mean K • Select Power-code by S.E. • Order lenses Empirically and/or with trial fit K-code / Power-code / Color / Material / OAD • Lens size • Predetermined • Match Corneal size by Best-fit HVID

  21. Orthokeratology The GOV System K-code: Mean K = (Steep K + Flat K) / 2 • Carry value up to 2 decimal places (0.01) • Km in Diopters Power Calculation: SE = Spherical Spec power – [K astigmatism / 2] • Spherical power must not be vertexed • K astigmatism = steep K – flat K (in Dioptres)

  22. Mean K/ S.E -1.50 -2.00 -2.50 -3.00 -3.50 -4.00 -4.50 -5.00 OAD 11.2 mm Best fit cornea 11.3~11.9 mm (OAD=95-97% of HVID) A 39.87~40.11 (40.00) 40.00/-1.5 40.00/-2.0 40.00/-2.5 40.00/-3.0 40.00/-3.5 40.00/-4.0 40.00/-4.5 40.00/-5.0 B 40.12~40.36 (40.25) 40.25/-1.5 40.25/-2.0 40.25/-2.5 40.25/-3.0 40.25/-3.5 40.25/-4.0 40.25/-4.5 40.25/-5.0 C 40.37~40.66 (40.50) 40.50/-1.5 40.50/-2.0 40.50/-2.5 40.50/-3.0 40.50/-3.5 40.50/-4.0 40.50/-4.5 40.50/-5.0 D 40.67~40.86 (40.75) 40.75/-1.5 40.75/-2.0 40.75/-2.5 40.75/-3.0 40.75/-3.5 40.75/-4.0 40.75/-4.5 40.75/-5.0 E 40.87~41.11 (41.00) 41.00/-1.5 41.00/-2.0 41.00/-2.5 41.00/-3.0 41.00/-3.5 41.00/-4.0 41.00/-4.5 41.00/-5.0 F 41.12~41.36 (41.25) 41.25/-1.5 41.25/-2.0 41.25/-2.5 41.25/-3.0 41.25/-3.5 41.25/-4.0 41.25/-4.5 41.25/-5.0 G 41.37~41.66 (41.50) 41.50/-1.5 41.50/-2.0 41.50/-2.5 41.50/-3.0 41.50/-3.5 41.50/-4.0 41.50/-4.5 41.50/-5.0 H 41.67~41.86 (41.75) 41.75/-1.5 41.75/-2.0 41.75/-2.5 41.75/-3.0 41.75/-3.5 41.75/-4.0 41.75/-4.5 41.75/-5.0 I 41.87~42.11 (42.00) 42.00/-1.5 42.00/-2.0 42.00/-2.5 42.00/-3.0 42.00/-3.5 42.00/-4.0 42.00/-4.5 42.00/-5.0 J 42.12~42.36 (42.25) 42.25/-1.5 42.25/-2.0 42.25/-2.5 42.25/-3.0 42.25/-3.5 42.25/-4.0 42.25/-4.5 42.25/-5.0 OAD 10.8 mm Best fit cornea: 11.2~11.6 mm (OAD=93-95% of HVID) K 42.37~42.66 (42.50) 42.50/-1.5 42.50/-2.0 42.50/-2.5 42.50/-3.0 42.50/-3.5 42.50/-4.0 42.50/-4.5 42.50/-5.0 L 42.67~42.86 (42.75) 42.75/-1.5 42.75/-2.0 42.75/-2.5 42.75/-3.0 42.75/-3.5 42.75/-4.0 42.75/-4.5 42.75/-5.0 M 42.87~43.11 (43.00) 43.00/-1.5 43.00/-2.0 43.00/-2.5 43.00/-3.0 43.00/-3.5 43.00/-4.0 43.00/-4.5 43.00/-5.0 N 43.12~43.36 (43.25) 43.25/-1.5 43.25/-2.0 43.25/-2.5 43.25/-3.0 43.25/-3.5 43.25/-4.0 43.25/-4.5 43.25/-5.0 O 43.37~43.66 (43.50) 43.50/-1.5 43.50/-2.0 43.50/-2.5 43.50/-3.0 43.50/-3.5 43.50/-4.0 43.50/-4.5 43.50/-5.0 P 43.67~43.86 (43.75) 43.75/-1.5 43.75/-2.0 43.75/-2.5 43.75/-3.0 43.75/-3.5 43.75/-4.0 43.75/-4.5 43.75/-5.0 OAD 10.4 mm Best fit cornea: 10.8~11.4 mm (OAD=92-94% of HVID) Q 43.87~44.11 (44.00) 44.00/-1.5 44.00/-2.0 44.00/-2.5 44.00/-3.0 44.00/-3.5 44.00/-4.0 44.00/-4.5 44.00/-5.0 R 44.12~44.36 (44.25) 44.25/-1.5 44.25/-2.0 44.25/-2.5 44.25/-3.0 44.25/-3.5 44.25/-4.0 44.25/-4.5 44.25/-5.0 S 44.37~44.66 (44.50) 44.50/-1.5 44.50/-2.0 44.50/-2.5 44.50/-3.0 44.50/-3.5 44.50/-4.0 44.50/-4.5 44.50/-5.0 T 44.67~44.86 (44.75) 44.75/-1.5 44.75/-2.0 44.75/-2.5 44.75/-3.0 44.75/-3.5 44.75/-4.0 44.75/-4.5 44.75/-5.0 U 44.87~45.11 (45.00) 45.00/-1.5 45.00/-2.0 45.00/-2.5 45.00/-3.0 45.00/-3.5 45.00/-4.0 45.00/-4.5 45.00/-5.0 V 45.12~45.36 (45.25) 45.25/-1.5 45.25/-2.0 45.25/-2.5 45.25/-3.0 45.25/-3.5 45.25/-4.0 45.25/-4.5 45.25/-5.0 W 45.37~45.66 (45.50) 45.50/-1.5 45.50/-2.0 45.50/-2.5 45.50/-3.0 45.50/-3.5 45.50/-4.0 45.50/-4.5 45.50/-5.0 X 45.67~45.86 (45.75) 45.75/-1.5 45.75/-2.0 45.75/-2.5 45.75/-3.0 45.75/-3.5 45.75/-4.0 45.75/-4.5 45.75/-5.0 Y 45.87~46.11 (46.00) 46.00/-1.5 46.00/-2.0 46.00/-2.5 46.00/-3.0 46.00/-3.5 46.00/-4.0 46.00/-4.5 46.00/-5.0 Z 46.12~46.36 (46.25) 46.25/-1.5 46.25/-2.0 46.25/-2.5 46.25/-3.0 46.25/-3.5 46.25/-4.0 46.25/-4.5 46.25/-5.0 ZA 46.37~46.66 (46.50) 46.50/-1.5 46.50/-2.0 46.50/-2.5 46.50/-3.0 46.50/-3.5 46.50/-4.0 46.50/-4.5 46.50/-5.0 ZB 46.67~46.86 (46.75) 46.75/-1.5 46.75/-2.0 46.75/-2.5 46.75/-3.0 46.75/-3.5 46.75/-4.0 46.75/-4.5 46.75/-5.0 ZC 46.87~47.11 (47.00) 47.00/-1.5 47.00/-2.0 47.00/-2.5 47.00/-3.0 47.00/-3.5 47.00/-4.0 47.00/-4.5 47.00/-5.0 ZD 47.12~47.36 (47.25) 47.25/-1.5 47.25/-2.0 47.25/-2.5 47.25/-3.0 47.25/-3.5 47.25/-4.0 47.25/-4.5 47.25/-5.0 ZE 47.37~47.66 (47.50) 47.50/-1.5 47.50/-2.0 47.50/-2.5 47.50/-3.0 47.50/-3.5 47.50/-4.0 47.50/-4.5 47.50/-5.0 Trial set

  23. Prescribe Empirically • Km: 42.87 x 44.75 @ 90 RX: - 3.50 - 1.50 x 180 • Determine K-code Mean K=(42.87 + 44.75) / 2 = 43.81 K-code = 43.75 • Determine Power-code S.E.= - 3.50 – [(44.75-42.87) / 2] = -4.44 Power-code= -4.50 • Empirically ordered by XMJ / (43.75) / -4.50 / 10.8 mm

  24. Empirically with trial fit • Prescribe a looser lens empirically • Subtract 0.50D from K code (flatter K code) • Add +0.50 D to power-code (less minus) • Order lens by: XMJ / (43.25) / -4.00 / 10.8 mm • Prescribe a tighter lens empirically • Add 0.50 D to K code (steeper K code) • Add -0.50 D to power code (more minus) • Order lens by: XMJ / (44.25) / -5.00 / 10.4 mm

  25. Prescribe by over refract trial lens • Select first trial lens by mean K XMJ/(43.75)/-3.00, if fit is loose tryXMJ/(44.25)/ -3.00 to tighten AC • Over refraction of XMJ/(44.25)/-3.00 = –1.50 D Power-code = -3.00 + (-1.50) = -4.50 • Order M4 lens by: XMJ/(44.25)/-4.50/10.4 mm (Predetermined OAD)

  26. As simple as 1-2-3 • Select K-code • Determine Power-code • Verify OAD (Lens size)

  27. The Aligned Fit

  28. Aligned Fit Good compression Good Seal off Good Seal off

  29. Trouble Shooting Ideal fit

  30. Trouble Shooting Bull’s Eye Pattern

  31. Trouble Shooting Alignment Fit

  32. Too Steep Fit

  33. Alignment Fit

  34. Steep Fit No Compression

  35. Flatten alignment curve • Up the column

  36. Steep Fit 4 Steps

  37. Steep Fit Steep fit – 6 Steps

  38. Trouble Shooting Central Islands

  39. Steep Fit No Compression

  40. Central Island Small areas of distortion along or near the visual axis

  41. Central Island Cause: • Alignment curve too tight • Excessive uncorrected astigmatism resulting in unequal forces on the cornea Solution: • Decrease sagittal depth of lens by flattening alignment curve • move up the column • Decentered lens must be centered • Flatten the BC if caused by uncorrected astigmatism • move one column right.

  42. Too Flat Fit

  43. Alignment Fit

  44. Flat Fit Too much bearing Sideway force induced Poor Seal off Poor Seal off

  45. Flat Fit Decentred Good compression Poor compression Good Seal off Poor Seal off

  46. Steepen alignment curve • Down the column

  47. Trouble Shooting Flat Fit – 4 Steps

  48. Trouble Shooting Smiley Face

  49. Flat Fit Decentred Good compression Poor seal off Good Seal off Poor Seal off

  50. Flat Fit Smiley Face Flat fitting lens decentered superiorly

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