Visual Fields

Question 1

Visual field definition

Answer 1

The entire area that can be seen when the eye is directed forward, including peripheral vision.

Question 2

Visual field vs Visual Acuity

Answer 2

Hmmm

Question 3

What is a Visual Field Test?

Answer 3

A test that measures the extent and distribution of the field of vision.

Question 4

Methods of Visual Field Testing

Answer 4

Confrontation visual field testing

Amsler grid

Tangent screen

Automated perimeter

Question 5

Why do VF testing?

Answer 5

Diseases can adversely affect VF
Medications can affect VF
Occupational safety standards are determined by VF (drivers license, pilot)
Determination of functional loss (loss of vision, whether or not insurance will cover)

Question 6

Diseases that can adversely affect VF

Answer 6

Glaucoma, strokes (CVA), tumors

Question 7

Levels of VF Testing

Answer 7

VF Screening,
Qualitative or diagnostic field testing,
Quantitative visual field testing

Question 8

Visual field screening

Answer 8

Generally done when VF loss unlikely, but possible

Should be quick, easy, and capable of eliciting a wide variety of defects

Question 9

Qualitative/diagnostic field testing

Answer 9

Designed to determine the characteristics of a V defect (location, borders, shape, size, etc)

Ex:
DL testing, ptosis functional loss assessment

Question 10

Quantitative visual field testing

Answer 10

Fully quantifies a known or suspected defect, so future changes detectable

Requires automated (full threshold) perimetry

Question 11

Incidence of VF loss (percentage)

Answer 11

About 3-5 %, 10-15% in 65+

Question 12

Are VF screenings required at comprehensive eye exams?

Answer 12

Nope, but recommended.

Question 13

What isn’t included in the binocular visual field?

Answer 13

Left and right monocular temporal crescents

Question 14

What is Confrontation VF?

Answer 14

Can be done in numerous ways

Quick and simple screening for VF loss

Doesn’t require special equipment

Sensitivity isn’t very high

Question 15

Counting Fingers technique

Answer 15

Version of Confrontation VF

Examiner faces pt,
Pt covers one eye,
Pt looks straight ahead,
Examiner flashes fingers in each quadrants while making sure pt remains fixated

Should not wear glasses due to frames’ blind spots

Question 16

Tips for obtaining reliable confrontation VFs:

Answer 16

Make sure target presented to your patient at corresponding at corresponding point in your own VF

Don’t make too hard or too easy

Make sure entire target remains completely within the quadrant

Recognize deceptive responses (feigned sight or malingering) and know how to detect it!

Question 17

Can patients still have 20/20 VA and VF loss?

Answer 17

Yessss

Question 18

A symptomatic field loss may be the only detectable evidence of a ____________________

Answer 18

Serious medical condition

Seriously

Question 19

When should VF screening testing be done?

Answer 19

At every comprehensive exam, and whenever possibility of VF loss arises

Question 20

Confrontation visual field examination can ruin lives, true or false.

Answer 20

False. Duh. It can save lives. And it can uncover otherwise undetectable pathology.

Question 21

Central field loss is usually, but not always, associated with:

Answer 21

visual acuity

That’s why central field loss isn’t routinely screened for

Question 22

Techniques for assessing central VFs

Answer 22

Amsler grid testing

Specialized automated VF test strategies

Question 23

Amsler Grid Testing

Answer 23

Simple, quick check for defects in central portion of visual field
Assesses central 10 degrees of VF
Qualitative assessment of macular function

Question 24

What is the macula?

Answer 24

Portion of the retina responsible for central vision

Question 25

When should Amsler Grid testing be done?

Answer 25

When suspected disorders of macula arise,

Can be given to patients to monitor at home

Question 26

Normal response of Amsler Grid

Answer 26

Dot at center,
All four corners,
No missing areas of grid,
No areas of grid distorted (no wavy lines)