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PAL Fitting, facial measurement and marking GS Shrestha, B.OptM.Optom Gauri S. Shrestha, M.Optom, FIACLE
Fitting PALs is an art.. <ul><li>It requires adequate training & skill  </li></ul><ul><li>It involves communication & coun...
And a science.. <ul><li>It requires : </li></ul><ul><li>A systematic approach </li></ul><ul><li>Understanding of potential...
What should be systematic approach.. 1) Identify the problem --questing the presbyope --remark the lenses  --check the fra...
-- verify the lens fitting -- observation of use  --confirm refraction and lens power  2) Possible signs and symptoms with...
Whom to fit ?   <ul><li>ALL PRESBYOPES ! </li></ul>BUT..
Contraindications <ul><li>Field of View  </li></ul>
Contraindications <ul><li>Direction of Gaze  </li></ul>
Contraindications <ul><li>Mobility / Head Movement  </li></ul>
Contraindications <ul><li>Anisometropia / Antimetropia </li></ul><ul><li>High Cylinders </li></ul><ul><li>Prisms </li></ul...
Patient selection <ul><li>   Patient requiring vision for occasional intermediate distances and for those who request an ...
   Previous bifocal wearer who demonstrate need for a  trifocal lens for occasional use  may enjoy the flexibility of PAL...
3) patients who are accustomed to wearing and are  satisfied with single vision lenses for near vision only 4) Patients wi...
Fitting ...
Step 1 <ul><li>Identification of  </li></ul><ul><li>Patient’s Requirements & Expectations </li></ul>
Useful tip <ul><li>Judge the motivation </li></ul><ul><li>Highlight the advantages, but mention the limitations as well </...
Step 2.  Frame Selection <ul><li>Frame shape </li></ul>Good Shape Bad Shape Good Depth Good Size Too Large Insufficient De...
  Frame Selection <ul><li>Back vertex distance  </li></ul><ul><li>Pantoscopic tilt </li></ul><ul><li>Facial wrap </li></ul>
Useful tip <ul><li>Prefer metal frames with adjustable nose pads </li></ul>
Step 3 <ul><li>Adjust before taking facial measurements </li></ul><ul><li>Adjust when delivering spectacles </li></ul>Fram...
<ul><li>When to Adjust </li></ul><ul><ul><li>Before taking the facial measurements </li></ul></ul><ul><ul><li>When deliver...
Step 3 <ul><li>Back vertex Distance - shorter </li></ul>Frame Adjustment Reduced BVD gives wider field of view
Step 3 <ul><li>Pantoscopic Tilt - 10 to 12 degrees </li></ul>Frame Adjustment Increase Pantoscopic Tilt increases near fie...
Step 3 <ul><li>Facial wrap - must not be too flat </li></ul>Frame Adjustment
Step 4 Monocular PD
Step 4 Monocular PD Monocular PD Monocular PD 32 29 61
Step 5 Monocular PD
Step 6 Marking the lens insert
Step 7 Fitting height
Useful tip <ul><li>Natural head posture </li></ul><ul><li>Sit at the same level as the patient </li></ul><ul><li>Check bin...
Step 8 Checking the cut out
Delivery .. <ul><li>Markings </li></ul><ul><li>Distance power & prism </li></ul><ul><li>Addition </li></ul><ul><li>Fitting...
Delivery .. On eye assessment Frame fit Fitting crosses
Delivery .. On eye assessment Distance Vision Near Vision
Delivery .. Delivery Instructions
Useful tip <ul><li>Use positive language </li></ul><ul><li>Remove the markings at the end </li></ul><ul><li>Maintain a rec...
Useful tip TAKE A BREAK !!!
3.  Facial Measurements <ul><li>Methods </li></ul><ul><ul><li>Distance method 1 </li></ul></ul><ul><ul><li>Distance method...
Facial Measurements <ul><li>Distance Method 1 </li></ul><ul><ul><li>Step 1:  Adjust the frame </li></ul></ul><ul><ul><li>S...
Facial Measurements <ul><li>Distance Method 1 </li></ul><ul><ul><li>Step 3:  Mark the HCL & PD on the dummy lenses </li></...
Facial Measurements <ul><li>Distance Method 1 </li></ul><ul><ul><li>Step 4:  Check the pupil height </li></ul></ul><ul><ul...
Facial Measurements <ul><li>Distance Method 1 </li></ul><ul><ul><li>Step 6:  Order the PD as per the pupillometer reading ...
Facial Measurements <ul><li>Distance Method 2 </li></ul><ul><ul><li>Step 1:  Adjust the frame </li></ul></ul><ul><ul><li>S...
Facial Measurements <ul><li>Distance Method 2 </li></ul><ul><ul><li>Step 3:  Place the frame on the patient and dot the pu...
3.  Facial Measurements <ul><li>Distance Method 2 </li></ul><ul><ul><li>Step 5:  Order the PD as per the pupillometer read...
Facial Measurements <ul><li>Near Method 1 </li></ul><ul><ul><li>Steps 1 - 5:  as per Distance Method 1 </li></ul></ul><ul>...
Facial Measurements <ul><li>Near Method 1 </li></ul><ul><ul><li>Step 7:  Place a mirror between the patient and you and ob...
Facial Measurements <ul><li>Near Method 1 </li></ul><ul><ul><li>Step 9:  Place the adjusted near visual circles on the lay...
Facial Measurements <ul><li>Near Method 2 </li></ul><ul><ul><li>Step 1:  Adjust the frame </li></ul></ul><ul><ul><li>Step ...
Facial Measurements <ul><li>Near Method 2 </li></ul><ul><ul><li>Step 3:  Mark the HCL & PD on the dummy lenses </li></ul><...
Facial Measurements <ul><li>Near Method 2 </li></ul><ul><ul><li>Step 4:  Check the pupil height </li></ul></ul><ul><ul><li...
Facial Measurements <ul><li>Near Method 2 </li></ul><ul><ul><li>Step 6:  Order the PD as per the pupillometer near PD read...
Facial Measurements <ul><li>Comparing the Methods </li></ul><ul><ul><li>Pre-marking the dummy lenses Vs dotting the lenses...
Lens Ordering <ul><li>PDs </li></ul><ul><li>Heights </li></ul><ul><ul><li>From the horizontal centre line (Datum) </li></u...
Lens Ordering <ul><li>Checking the cut-out </li></ul>
Delivery 1.  Pre-delivery Verification <ul><li>Checking the markings </li></ul><ul><li>Checking the frame details </li></u...
Re-locating Progressive Lens Markings <ul><li>1.  Find micro-engraved permanent markings </li></ul><ul><li>2.  Mark the po...
Re-locating Progressive Lens Markings <ul><li>4.  Lay the lens on the chart with the marked locators in the correct positi...
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Progressive lens measurement

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Progressive lens measurement

  1. 1. PAL Fitting, facial measurement and marking GS Shrestha, B.OptM.Optom Gauri S. Shrestha, M.Optom, FIACLE
  2. 2. Fitting PALs is an art.. <ul><li>It requires adequate training & skill </li></ul><ul><li>It involves communication & counselling skills and convincing power </li></ul>
  3. 3. And a science.. <ul><li>It requires : </li></ul><ul><li>A systematic approach </li></ul><ul><li>Understanding of potential problems </li></ul><ul><li>In-depth study of designs </li></ul>
  4. 4. What should be systematic approach.. 1) Identify the problem --questing the presbyope --remark the lenses --check the frame fit 1.frame level 4.facial wrap 2.temple level 5.vertex distance 3.pantoscopic tilt
  5. 5. -- verify the lens fitting -- observation of use --confirm refraction and lens power 2) Possible signs and symptoms with PAL’s 3) Possible causes of problems with PAL’s What should be systematic approach..
  6. 6. Whom to fit ? <ul><li>ALL PRESBYOPES ! </li></ul>BUT..
  7. 7. Contraindications <ul><li>Field of View </li></ul>
  8. 8. Contraindications <ul><li>Direction of Gaze </li></ul>
  9. 9. Contraindications <ul><li>Mobility / Head Movement </li></ul>
  10. 10. Contraindications <ul><li>Anisometropia / Antimetropia </li></ul><ul><li>High Cylinders </li></ul><ul><li>Prisms </li></ul><ul><ul><li>Prescriptions </li></ul></ul>
  11. 11. Patient selection <ul><li> Patient requiring vision for occasional intermediate distances and for those who request an invisible bifocal </li></ul><ul><li>Patients who resist convention bifocal or trifocals because of the “lines” are strongly motivated and are excellent candidates for PAL </li></ul><ul><li> Emerging presbyopes are also good candidates </li></ul>
  12. 12.  Previous bifocal wearer who demonstrate need for a trifocal lens for occasional use may enjoy the flexibility of PALs  PALs should not be recommended for all presbyopes however discretion should be exercised, especially with the following patients 1) currently bifocal or trifocal wearer who are completely satisfied with their lenses 2) Patients with large oculomotor imbalances who require prism Patient selection
  13. 13. 3) patients who are accustomed to wearing and are satisfied with single vision lenses for near vision only 4) Patients with a significant amount of anisometropia(3D or >) 5) Patient who need adds of high power and who have large pupils 6) Patients who are nervous, tense, impatient, and generally intolerant of health-care devices Patient selection
  14. 14. Fitting ...
  15. 15. Step 1 <ul><li>Identification of </li></ul><ul><li>Patient’s Requirements & Expectations </li></ul>
  16. 16. Useful tip <ul><li>Judge the motivation </li></ul><ul><li>Highlight the advantages, but mention the limitations as well </li></ul>
  17. 17. Step 2. Frame Selection <ul><li>Frame shape </li></ul>Good Shape Bad Shape Good Depth Good Size Too Large Insufficient Depth Frame size Frame depth
  18. 18. Frame Selection <ul><li>Back vertex distance </li></ul><ul><li>Pantoscopic tilt </li></ul><ul><li>Facial wrap </li></ul>
  19. 19. Useful tip <ul><li>Prefer metal frames with adjustable nose pads </li></ul>
  20. 20. Step 3 <ul><li>Adjust before taking facial measurements </li></ul><ul><li>Adjust when delivering spectacles </li></ul>Frame Adjustment
  21. 21. <ul><li>When to Adjust </li></ul><ul><ul><li>Before taking the facial measurements </li></ul></ul><ul><ul><li>When delivering the spectacles </li></ul></ul>
  22. 22. Step 3 <ul><li>Back vertex Distance - shorter </li></ul>Frame Adjustment Reduced BVD gives wider field of view
  23. 23. Step 3 <ul><li>Pantoscopic Tilt - 10 to 12 degrees </li></ul>Frame Adjustment Increase Pantoscopic Tilt increases near field of view
  24. 24. Step 3 <ul><li>Facial wrap - must not be too flat </li></ul>Frame Adjustment
  25. 25. Step 4 Monocular PD
  26. 26. Step 4 Monocular PD Monocular PD Monocular PD 32 29 61
  27. 27. Step 5 Monocular PD
  28. 28. Step 6 Marking the lens insert
  29. 29. Step 7 Fitting height
  30. 30. Useful tip <ul><li>Natural head posture </li></ul><ul><li>Sit at the same level as the patient </li></ul><ul><li>Check binocularly from a dist. of 1 meter </li></ul><ul><li>Use a fine marker </li></ul>
  31. 31. Step 8 Checking the cut out
  32. 32. Delivery .. <ul><li>Markings </li></ul><ul><li>Distance power & prism </li></ul><ul><li>Addition </li></ul><ul><li>Fitting cross heights & PDs </li></ul>
  33. 33. Delivery .. On eye assessment Frame fit Fitting crosses
  34. 34. Delivery .. On eye assessment Distance Vision Near Vision
  35. 35. Delivery .. Delivery Instructions
  36. 36. Useful tip <ul><li>Use positive language </li></ul><ul><li>Remove the markings at the end </li></ul><ul><li>Maintain a record of the order forms </li></ul>
  37. 37. Useful tip TAKE A BREAK !!!
  38. 38. 3. Facial Measurements <ul><li>Methods </li></ul><ul><ul><li>Distance method 1 </li></ul></ul><ul><ul><li>Distance method 2 </li></ul></ul><ul><ul><li>Near method 1 (the mirror method) </li></ul></ul><ul><ul><li>Near method 2 </li></ul></ul>
  39. 39. Facial Measurements <ul><li>Distance Method 1 </li></ul><ul><ul><li>Step 1: Adjust the frame </li></ul></ul><ul><ul><li>Step 2: Measure the monocular PDs with the pupillometer </li></ul></ul>Monocular PD Monocular PD 32 29 61
  40. 40. Facial Measurements <ul><li>Distance Method 1 </li></ul><ul><ul><li>Step 3: Mark the HCL & PD on the dummy lenses </li></ul></ul>
  41. 41. Facial Measurements <ul><li>Distance Method 1 </li></ul><ul><ul><li>Step 4: Check the pupil height </li></ul></ul><ul><ul><li>Step 5: Check the height while talking to the patient </li></ul></ul>
  42. 42. Facial Measurements <ul><li>Distance Method 1 </li></ul><ul><ul><li>Step 6: Order the PD as per the pupillometer reading & height as per step 5 </li></ul></ul>
  43. 43. Facial Measurements <ul><li>Distance Method 2 </li></ul><ul><ul><li>Step 1: Adjust the frame </li></ul></ul><ul><ul><li>Step 2: Measure the monocular PDs with the pupillometer </li></ul></ul>
  44. 44. Facial Measurements <ul><li>Distance Method 2 </li></ul><ul><ul><li>Step 3: Place the frame on the patient and dot the pupil centre </li></ul></ul><ul><ul><li>Step 4: Check the height while taking to the patient </li></ul></ul>Dotting the pupil centre
  45. 45. 3. Facial Measurements <ul><li>Distance Method 2 </li></ul><ul><ul><li>Step 5: Order the PD as per the pupillometer reading & height as per step 4 </li></ul></ul>
  46. 46. Facial Measurements <ul><li>Near Method 1 </li></ul><ul><ul><li>Steps 1 - 5: as per Distance Method 1 </li></ul></ul><ul><ul><li>Step 6: Mark the distance and near visual point circles </li></ul></ul>
  47. 47. Facial Measurements <ul><li>Near Method 1 </li></ul><ul><ul><li>Step 7: Place a mirror between the patient and you and observe through the mirror the patient’s eyes when looking at the mirror </li></ul></ul><ul><ul><li>Step 8: Adjust the near visual circles if necessary to correspond with the patient’s lines of sight </li></ul></ul>
  48. 48. Facial Measurements <ul><li>Near Method 1 </li></ul><ul><ul><li>Step 9: Place the adjusted near visual circles on the layout chart to determine the final position of the fitting crosses. </li></ul></ul>
  49. 49. Facial Measurements <ul><li>Near Method 2 </li></ul><ul><ul><li>Step 1: Adjust the frame </li></ul></ul><ul><ul><li>Step 2: Measure the monocular near CDs with the pupillometer </li></ul></ul>Monocular PD Monocular PD 32 29 61
  50. 50. Facial Measurements <ul><li>Near Method 2 </li></ul><ul><ul><li>Step 3: Mark the HCL & PD on the dummy lenses </li></ul></ul>
  51. 51. Facial Measurements <ul><li>Near Method 2 </li></ul><ul><ul><li>Step 4: Check the pupil height </li></ul></ul><ul><ul><li>Step 5: Check the height while talking to the patient </li></ul></ul>
  52. 52. Facial Measurements <ul><li>Near Method 2 </li></ul><ul><ul><li>Step 6: Order the PD as per the pupillometer near PD reading plus 2.5 mm each eye & height as per step 5 </li></ul></ul>
  53. 53. Facial Measurements <ul><li>Comparing the Methods </li></ul><ul><ul><li>Pre-marking the dummy lenses Vs dotting the lenses </li></ul></ul><ul><ul><li>Pupillometer vs PD rule or dots </li></ul></ul>
  54. 54. Lens Ordering <ul><li>PDs </li></ul><ul><li>Heights </li></ul><ul><ul><li>From the horizontal centre line (Datum) </li></ul></ul><ul><ul><li>From the frame bottom </li></ul></ul>
  55. 55. Lens Ordering <ul><li>Checking the cut-out </li></ul>
  56. 56. Delivery 1. Pre-delivery Verification <ul><li>Checking the markings </li></ul><ul><li>Checking the frame details </li></ul><ul><li>Checking the distance power and prism </li></ul>
  57. 57. Re-locating Progressive Lens Markings <ul><li>1. Find micro-engraved permanent markings </li></ul><ul><li>2. Mark the position of the horizontal locators </li></ul><ul><li>3. Select manufacturer’s layout chart for the correct lens type </li></ul>
  58. 58. Re-locating Progressive Lens Markings <ul><li>4. Lay the lens on the chart with the marked locators in the correct position </li></ul><ul><li>5. Trace the distance and near reference circles, the fitting cross and the prism reference point </li></ul>

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