MOR Review

Question 1

What does MOR stand for?

Answer 1

Manifest over Radius

Question 2

How do you find the Tear Layer ?

Answer 2

Sphere = how much flatter or steeper you are fitting the lens (based on Boston fitting guide)
Cyl= the difference between the two meridians
Axis= axis of the flatter K

Question 3

How to determine base curve of RGP?

Answer 3

Use flat K and plug into this formula:
337.5 / Flat K

If flat k is 42.75 bc is
337.5/42.75 = 7.89 or 7.9 Base Curve

Question 4

What is the default power of a trial lens for MOR ?

Answer 4

-3.00 D

Question 5

Steps for MOR

Answer 5

1. Compensate Rx
2. Calculate BOZR
   Use the boston fitting guide to (+) or (-) from the flattest k
   Turn flat K into a BC (337.5/flat k)
   3.Calculate Tear Layer
   4.Calculate looking through (Tear layer + Trial lens) Trial lens is -3.00
3. Calculate expected MOR
4. Calculate first refracting lens (fogging)
5. Calculate final lens power

Question 6

How to do an Empirical Fit

Answer 6

FLO + TL
Or
Rx-TL

Question 7

Calculate MOR
Spectacle rx: -4.25-1.25 x 150
VD 13 mm
K’s 43.00 @ 150 / 44.00 @ 060

Answer 7

Compensate:
F150=
-4.25/1-(0.013)(-4.25)
=-4.03
F060=
-5.50/1-(0.013)(-5.50)
=-5.13

1. Rx -4.00-1.00x150
2. BOZR:
3. 00-0.50 (BOSTON GUIDE) = 42.50
4. 5/42.5 = 7.94
5. TL: -0.50-1.00x150
6. Look through: -3.00 + Tear Layer
   - 3.50-1.00x150
7. Expected MOR: Rx-L/T
   - 4.00-1.00x150 - -3.50-1.00x150 = -0.50 (Actual MOR)
8. First Refracting lens: +3.00+ (-0.50) = +2.50
9. Final lens power: Actual MOR + Diagnostic Lens
   - 0.50 + -3.00 = -3.50

Question 8

For every 0.10 mm change in BC; Rx will change by ___

Answer 8

0.50 D

Question 9

How does power change on RGP if changing BC

Answer 9

SAM/FAP
If making BC steeper—ADD MINUS
If making BC flatter—ADD PLUS

Question 10

After doing MOR the Final Lens Order is -3.25 but you want to change the lens BC from 8.2 to 8.1

Answer 10

To make the lens steeper you have to add Minus power (-0.50 for the .10 mm change)
-3.25 + (-0.50) = -3.75
New FLO is -3.75

Question 11

Your patient is wearing an RGP that has a diameter of 9.6 mm and base curve of 7.9 mm
The lens is too flat—how can you make it fit steeper?

Answer 11

Increase the diameter to 9.7
OR
Decrease the diameter to 7.8

Question 12

Your patient is wearing an RGP that has a diameter of 9.6 mm and base curve of 7.9 mm.
The lens is fitting too steep, how can you make it flatter?

Answer 12

Decrease the diameter to 9.5

Increase the base curve to 8.0

Question 13

Without doing a full MOR, if a patient has an rx of -3.50 and you are fitting 0.5 diopter flatter, what is the final lens order?

Answer 13

The final lens order is -3.00 D