What to do for BV and Near Testing
Near Testing: NRA/PRA OR FCC
NRA
1. Put Rx from refraction or Hx Rx in the phoropter.
2. Put in patient’s distance pd and fold the wings in.
3. Attach near rod and Rotary Chart to phoropter—away from the patient.
4. Put the phoropter in front of patient, get them comfortable, and lock it.
5. Turn on stand lamp and put it on the near chart. NO SHADOWS.
6. Make sure Rotary Chart is at 40 cm and turn it to #5: 20/20 LOL
7. Check to see that patient can see chart: “Looking at the chart I just put up, can you see that line of letters clearly?”
- If “no,” add plus lenses until it’s clear, then explain the test. The plus lenses added to the distance Rx will be used for all other near tests.
- If “yes,” explain the test.
8. Explain the test: “Now I want you to look at this line of letters while I put some lenses in front of your eyes. The letters will get blurry and I want to know when they get blurry and you can’t focus and make them clear.”
9. Add plus lenses in +0.25D steps, going slowly so that they can try to clear it, until they get to first sustained blur.
10. If they say it’s blurry, ask: “Can you make it clear?”
- If “no,” stop there and record LIP.
- If “yes,” continue to add plus lenses until they get to first sustained blur.
PRA
1. Explain the test: “Now I’m going to put some more lenses in front of your eyes. It should get clearer, but then blur again. I want you to tell me when it gets blurry and you can’t make it clear.”
2. Add minus lenses in -0.25D steps, going slowly so that they can try to clear it, until they get to first sustained blur.
3. If they say it’s blurry, ask: “Can you make it clear?”
- If “no,” stop there and record LIP.
- If “yes,” continue to add minus lenses until they get to the first sustained blur.
Calculating/Recording
4. Calculate NET NRA = LIP – Rx
5. Calculate NET PRA = LIP – Rx
6. Record:
NRA (LIP):
Net:
PRA (LIP):
Net:
FCC
1. Put Rx from refraction or Hx Rx in the phoropter.
2. Put in patient’s distance pd and fold the wings in.
3. Turn to +/-0.50 lenses for both eyes
4. Attach near rod and Rotary Chart to phoropter—away from the patient.
5. Put the phoropter in front of patient, get them comfortable, and lock it.
6. Turn lights to “dim,” with no stand lamp
7. Make sure Rotary Chart is at 40 cm and turn it to #3: Cross Grid
8. Check to see that the patient can see the target clearly
9. Explain the test: “What we’re going to do now, is get a measure of what prescription you might need when looking up close. Do you see that cross pattern clearly? I want you to look at the chart and tell me which lines are clearer and darker: the ones going up and down or the ones going across”
- If “across,” add plus lenses and ask when the lines up and down get darker/clearer
- If “up and” down, move on
10. Add minus lenses -0.25D at a time slowly, until patient says the lines going across are clearer/darker
11. Turn Room lights back up and TAKE OUT +/-0.50 lenses
Calculate/Record
12. Calculate FCC: FCC = LIP – Rx
13. Record FCC
FCC (LIP):
Net:
Phorias: Von Graefe
Von Graefe Phorias
1. Give patient an add if one was found during NRA/PRA or FCC
2. Make sure the lights are turned up to bright with the stand lamp on
3. Flip in Risley Prisms
4. Ask patient to close eyes/sit back, then turn prisms to 6ΔBD OD and 12 Δ BI OS
5. Explain the test: “Now I’m going to perform a test to see how your eyes are working together. You should see two images and I’m going to move these lenses so that they line up.”
6. Confirm that two images are seen, one up and one down, If only one image:
- Make sure both eyes are unoccluded
- Switch BI to BO, they may have enough exophoria that the 12 ΔBI is correcting it
Horizontal Phorias
7. Turn Rotary Chart to #10 at 40cm: Vertical Line
8. Explain further: “I want you to look at the two charts but focus on the top chart. I’m going to make these lines line up and I want you to tell me when they are in line like buttons on a shirt.”
9. Move OS prisms toward 0, or further BO, until you they tell you that they are lined up
Recording
10. If patient says “lined up” at a BI value record: __ Δ XP
11. If patient says “linde up” at a BO value record: __ Δ EP
Vertical Phorias
12. Flip Rotary Chart to reverse side, #4: Horizontal Line
13. Make sure that patient still sees two charts
14. Explain test: “Now we’re going to do the same thing except this time I want you to tell me when these two lines are lined up like headlights on a car.”
15. Move OD prisms more slowly toward 0, or further BU, until they tell you “lined up”
Recording
16. If patient says “lined up” at a BD value, record (to the nearest 0.5 Δ): __ Δ Right Hyper
17. If patient says “lined up” at a BU value, record (to the nearest 0.5 Δ): __ Δ Left Hyper
Vergences: In Phoropter (Risley Prisms) OR Out of Phoropter (Prism Bar)
In-Phoropter Vergences
1. Give patient near add if found necessary with NRA/PRA or FCC
2. Make sure to do BI Vergences FIRST
Horizontal BI Vergences
3. Turn Rotary Chart to #10: Vertical Line at 40cm
4. Turn both Risley Prisms to 0 Δ, and to Horizontal Testing Position
5. Explain the test: “I’m going to further test how your eyes are working together. You should see the target clearly now. I’m going to be changing the lenses in front of your eyes and you may see the letters blur. Let me know if and when they blur and then when they break apart and stay apart.”
6. Begin moving both prisms BI at the same time, slowly, trying to keep them at the same pace
7. Note the blur (if any) and the break values
8. Explain recovery: “Okay, great, now I’m going to make the lines further apart, and then I’ll bring them back together. Let me know when you see them as one line again, even if it’s blurry”
9. Increase BI prism, then decrease until Recovery
Recording
10. BI: blur/break/recovery
Horizontal BO Vergences
11. Turn Risley Prisms back to 0
12. Confirm that patient sees a single line and it’s clear
13. Explain the test: “Now we’re going to do the same thing. Just let me know if and when the line blurs and when it breaks apart.”
14. Begin moving both prisms BO at the same time, slowly, trying to keep them at the same pace
15. Note the blur (if any) and the break values
16. Explain recovery: “Okay, great, now I’m going to make the lines further apart, and then I’ll bring them back together. Let me know when you see them as one line again, even if it’s blurry”
17. Increase BO prism, then decrease until Recovery
Recording
18. BO: blur/break/recovery
Vertical BU Vergences
1. Turn Rotary Chart to #5: Horizontal Line at 40cm
2. Turn both Risley Prisms to 0 Δ, and to Vertical Testing Position
3. Explain the test: “I’m going to further test how your eyes are working together. You should see the target clearly now. I’m going to be changing the lenses in front of your eyes and you may see the letters blur. Let me know if and when they blur and then when they break apart and stay apart.”
4. Begin moving ONE prism BU (OD), slowly
5. Note the blur (if any) and the break values
6. Explain recovery: “Okay, great, now I’m going to make the lines further apart, and then I’ll bring them back together. Let me know when you see them as one line again, even if it’s blurry”
7. Increase BU prism, then decrease until Recovery
Recording
8. BU (OD or OS): blur/break/recovery
Vertical BD Vergences
9. Turn Risley Prisms to 0 Δ
10. Explain the test: “We’re going to do the same thing one last time and I want you to tell me when the line blurs, breaks, and comes back to one line.”
11. Beging moving ONE prism BD (OD), slowly
12. Note the blur (if any) and the break values
13. Increase BD prism, then decrease until Recovery
Recording
14. BD (OD or OS): blur/break/recovery
NOTE: IF the patient does not report a blur at an excessively high value or if they say it appears to be moving to one side, START OVER. They have suppressed an eye and you should probably go more slowly.
Prism Bar Vergences
1. Remove Phoropter but turn it and the Rotary Chart so that you can use the chart as the target (NOTE: chart should be almost directly above patient’s knees for 40 cm)
2. Give patient near add if found necessary with NRA/PRA or FCC by asking professor to put Jenelli/Halburg clips or trial frame on patient
3. Make sure to do BI Vergences FIRST: Horizontal Prism
Horizontal BI Vergences
4. Turn Rotary Chart to #10: Vertical Line at 40cm
5. Make sure that target is clear
6. Hold Horizontal Prisms BI in front of OD
7. Explain the test: “I’m going to further test how your eyes are working together. You should see the target clearly now. I’m going to be changing these prisms in front of your eyes and as I move them, you may see the letters blur. Let me know if and when they blur and then when they break apart and stay apart.”
8. Begin moving BI prisms upward, slowly, trying to move at the same pace
9. Note the blur (if any) and the break values
10. Explain recovery: “Okay, great, now I’m going to make the lines further apart, and then I’ll bring them back together. Let me know when you see them as one line again, even if it’s blurry”
11. Increase BI prism, then decrease until Recovery
Recording
12. BI: blur/break/recovery
Horizontal BO Vergences
13. Hold Horizontal Prisms BO over OS
14. Confirm that patient sees a single line and it’s clear
15. Explain the test: “Now we’re going to do the same thing. Just let me know if and when the line blurs and when it breaks apart.”
16. Begin moving BO prisms upward, slowly, trying to move at the same pace
17. Note the blur (if any) and the break values
18. Explain recovery: “Okay, great, now I’m going to make the lines further apart, and then I’ll bring them back together. Let me know when you see them as one line again, even if it’s blurry”
19. Increase BO prism, then decrease until Recovery
Recording
20. BO: blur/break/recovery
Vertical BU Vergences
15. Turn Rotary Chart to #4: Horizontal Line at 40cm
16. Hold Vertical Prisms BU in front of OD
17. Explain the test: “Again, we’ll do the same thing and I’ll be changing the prisms in front of your eyes and you may see the letters blur. Let me know if and when they blur and then when they break apart and stay apart.”
18. Begin increasing BU prisms (OD), slowly
19. Note the blur (if any) and the break values
20. Explain recovery: “Okay, great, now I’m going to make the lines further apart, and then I’ll bring them back together. Let me know when you see them as one line again, even if it’s blurry”
21. Increase BU prism, then decrease until Recovery
Recording
22. BU: blur/break/recovery
Vertical BD Vergences
23. Turn Risley Prisms to 0 Δ
24. Explain the test: “We’re going to do the same thing one last time and I want you to tell me when the line blurs, breaks, and comes back to one line.”
25. Beging increasing BD prisms (OD), slowly
26. Note the blur (if any) and the break values
27. Increase BD prism, then decrease until Recovery
Recording
BD: blur/break/recovery
Binocular Vision Test: Maddox Rod OR Hirschberg OR Worth 4-Dot
Maddox Rod
1. Give patient near add if needed: Hx near Rx/Trial Frame/Janelli clips on Hx
2. Clean Cover Paddle
3. Ask patient to hold Maddox Rod over OD with lines VERTICAL
4. Hold transilluminator/penlight at 40 cm in Primary Gaze (straight ahead)
5. Explain test and ask patient to look at the light: “Now I’m going to see how your eyes work together and I want you to look right at my light. You should see the light and a red line going across. Tell me where that line is in relation to the light: is it above the light, below the light or directly on the light?”
6. If patient says:
a. “Above the light,” neutralize with BU OD or BD OS (RIGHT HYPER)
b. “Below the light,” neutralize with BD OD or BU OS (LEFT HYPER)
c. “In the center of the light,” there is no vertical phoria
7. Repeat in Downward Gaze