Clinical: Pupillometry And Brightness Acuity Test

Question 1

Is measuring pupillary distances with a ruler subjective or objective?

Answer 1

Subjective. Hard to obtain a completely accurate measurement

Question 2

What does a Pupillometer measure?

Answer 2

Precise pupillary distance

Question 3

What is the dial on the pupillometer for?

Answer 3

Working distance

Question 4

For multifocals, would you test both distance and near in the pupillometer?

Answer 4

Yes

Question 5

If monocular PDs are different by 1.5 mm or more when testing with the pupillometer what should you do?

Answer 5

Repeat the measurements

Question 6

Pupillometry steps

Answer 6

1. Clean the pupillometer
2. Turn the viewing distance knob to the appropriate distance
3. Check viewing setting and select monocular or binocular
4. Tell patient to rest both elbows on the table and bring pupillometer close them like they are looking through binoculars
5. Instruct the patient to look at the light on the inside
6. Align the vertical lines within the device with the light reflex on the patients pupil for the right eye on the control slider
7. Repeat for left eye
8. Bring device away from the patient and record monocular PDs
9. Repeat with other distances as needed
10. Store pupillometer face UP (numbers facing upward)

Question 7

Pupillometers are meant to simulate __________

Answer 7

Glasses

Question 8

A patient presents with a large tropia, should you measure their PD in binocular mode or monocular mode with the pupillometer?

Answer 8

Monocular mode

Question 9

All non-tropia situations should be measured in what way?

Answer 9

Binocularly

Question 10

How does the viewing distance setting of 40 cm change the PD measurement?

Answer 10

Makes the PD measurement smaller than if taken using the infinity viewing distance setting.

Question 11

Near PD is ________ than Distance PD. How much?

Answer 11

Smaller - usually 3-4 mm

Question 12

What does brightness acuity testing measure?

Answer 12

The acuity of a patient in glare situations

Question 13

Glare is disabling due to scattering of light. What is a common condition that causes glare issues?

Answer 13

Cataracts, especially cortical cataracts

Question 14

Indications for performing Brightness Acuity Testing

Answer 14

1. To determine visual acuity with glare
2. To see if a patient with significant symptoms will qualify for cataract surgery

Question 15

Is BAT performed while dilated?

Answer 15

NO, BAT must be performed without dilation

Question 16

BAT is used to simulate glare/headlights around a ___________

Answer 16

Central image

Question 17

A normal eye will suffer ___________ visual acuity loss with BAT

Answer 17

No or minimal

Question 18

Brightness Acuity Test Steps

Answer 18

1. Have patient wear best correction
2. Occlude eye not being tested
3. Display VA chart with multiple lines that has the patients BCVA on the bottom line
4. Turn the BAT on and select brightness desired
5. Remove the cover of the BAT
6. Have the patient look through the hole in the BAT and tell you the lowest line they can read as soon as possible. Do not give the patient time to adjust
7. Repeat with the other eye

Question 19

Recording example of BAT

Answer 19

Visual acuity with BAT OD: 20/40, OS: 20/60

Question 20

If the VA is reduced by ________ lines, glare has a significant impact on a patients vision and this may be considered qualifying for cataract surgery

Answer 20

2 lines

Question 21

If VA is _______ or worse in the presence of significant cataracts, they may qualify for surgery

Answer 21

20/50 or worse

Question 22

A 65 year old patient complains for difficulty driving at night with glare for 1 year. He no longer feels comfortable driving at night. You test his visual acuity and find OD: 20/30, OS: 20/40. You look into his eyes undilated with the slit lamp and see visually significant cataracts. You decide to test his eyes with BAT on the medium setting and find his visual acuity to be OD: 20/40, OS: 20/60. What has BAT demonstrated?

Answer 22

OS qualifies for cataract surgery but OD does not

OS showed decreased of two lines, while OD was one line

Question 23

When performing BAT, should VA ever get better when measuring?

Answer 23

No, if it does this can indicate the test was not performed correctly.

The VA should always stay the same or get worse.

Question 24

What does Potential Acuity Meter test for?

Answer 24

Estimates the visual acuity after potential cataract surgery when the patient has multiple conditions

Question 25

Example: Would you use PAM on a patient with these conditions, cataracts, macular problem, optic nerve problem, neurological problem?

Answer 25

Yes

Question 26

While performing PAM, if VA does not improve, is cataract surgery likely to be recommended/performed?

Answer 26

No, because the cataract would not be the main contributor to the vision loss, therefore performing cataract surgery would not benefit the patients vision enough.

Question 27

When performing PAM, should the patient be dilated? Why or why not?

Answer 27

Yes so that the light can get around the opacities

Question 28

3 major Potential Acuity Meter designs:

Answer 28

Slit Lamp projected chart Super Pinhole Laser Interferometer

Question 29

How does Slit Lamp Projected chart work for PAM?

Answer 29

Projects an image of a Snellen chart through the pupil using a 0.1mm bright light. The patient then reads the lowest line possible

Question 30

Slit Lamp Projected Chart contains a knob that allows spherical equivalent to be adjusted. Why is this useful?

Answer 30

Allows for better clarity for the patient and to adjust for the fact that the patient cannot wear glasses behind the slit lamp

Question 31

How does Super Pinhole work for PAM?

Answer 31

System uses a brightly illuminated LogMAR chart in combination with a pinhole to demonstrate best acuity

Question 32

Super Pinhole test is performed and calibrated for _______ feet

Answer 32

5 feet

Question 33

How does Laser Interferometer work for PAM?

Answer 33

System creates a red and black grating target in order to estimate potential visual acuity

Question 34

When using Laser Interferometer for PAM, if the patient has a refractive error of 6D or more, should glasses be used?

Answer 34

Yes

Question 35

How should gratings be oriented at the beginning of Laser Interferometer for PAM?

Answer 35

Larger and gradually change the orientation with each size tested ## Footnote Smaller grating identified = better VA

Question 36

What should be listed when recording PAM?

Answer 36

The type of PAM performed VA for both eyes

Question 37

A 70 year old female patient has moderate macular degeneration and a cataract. She sees 20/50 OD, OS, OU. Her retinal specialist suggested she would be a good candidate for cataract surgery. She wants to know if cataract surgery will help her see better. Using PAM, you measure her VA as 20/40 OD, OS, OU. What is the largest contributor to her vision loss - AMD or Cataracts? What is your cataract surgery recommendation?

Answer 37

Largest contributor is AMD, as PAM did not improve VAs significantly ## Footnote No, cataract surgery is not recommended as VA was better but not significantly as it did not improve by 2+ lines.