LOW VISION WORK UP

Low Vision Work Up


1. History


Just like any other exams, history is crucial because it drives the rest of the exam. Every patient has a chief complaint or a need. It is up to the clinician to ask appropriate questions and to set a few initial goals for the patient. Don’t be satisfied with a chief complaint of “I’m just here for a low vision exam.” Questions may include:


Chief complaints

Patient’s goals: near, intermediate and distance

Hobbies

Currently using any devices or wearing glasses?

Any devices patient tried in the past? Successful?

Any issues with activities of daily living?

Any problems with glare or lighting?

Mobility issues?


2. Distance VA


Use patient’s current glasses

First attempt Snellen chart (unless VA is known to be poorer than what can be obtained with Snellen chart)

Alternative charts

Feinbloom chart

Hold chart at 5 or 10 ft for easy conversion to Snellen equivalent

I always like to start a couple lines above expected VA to build patient’s confidence

One disadvantage is difficulty with refraction using Feinbloom chart (unless there’s another person holding the chart for you)

ETDRS

Easily moveable and able to stand on own without you holding it

Advantage: more letter options per line

Good chart when doing refraction

Record both central & eccentric VAs

Attempt eccentric viewing if patient is not already doing so. Record eccentric viewing from patient’s view.

3. Manifest Refraction


Use current specs Rx as starting point

May do autorefraction or retinoscopy for starting point if patient doesn’t wear glasses

Use phoropter if possible

If patient uses any eccentric viewing, it is HIGHLY recommended to perform trial frame refraction

Remember just noticeable difference!

Record both best corrected central and eccentric viewing VAs


4. Contrast Sensitivity


There are many contrast sensitivity tests. One more commonly used is the Mars Letter Contrast Sensitivity.

Test OD and OS separately & with near correction

Record log contrast sensitivity and level of impairment

5. Visual Field


Test monocularly then binocularly

Record:

Horizontal and vertical field

If there is any scotoma: record size and location

Note the area with the largest continuous visual field- important for scanning training

Variety of visual field machines (we are looking for areas of useable vision)

Arc perimeter

Goldmann visual field

Amsler grid (helps locate location of scotoma, but not size of scotoma)

Humphrey visual field & Octopus may not be the best because of reduced vision

6. Color Vision


Test monocularly

Ishihara or Farnsworth D-15

7. Near VA


Remember to include add over manifest refraction (if patient is presbyopic)

Test OD/OS/OU

Test at 40 cm or measure distance patient prefers

Use good lighting!

Record distance tested in meters and smallest M notation read

Example: 0.4m/3M

Record preferred eye        (REFERENCE:::: www.optometrystudent.com)




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