Visual Acuity Flashcards
1
Q
What is visual acuity?
A
- Most common form of clinical measurement for visual function
- Measures ability to receive, transmit and interpret visual images
- Visual status of patient: myopia, hyperopic, astig, amblyopia, cat. surgery, ect.
2
Q
Measuring/Recording VA
A
- Monocularly, OD first
- Record w/ or w/o correction: SC, without; CC, with
- Start at 20/20, go bigger if nec.
3
Q
Recording VA
A
Example: If patient can see 3 correct on the 20/30 line but nothing on the 20/25 their VA is 20/30-3
4
Q
Objectives of testing VA
A
- Determines best CC VA
- Determines if decreased vision is due to refractive error or pathology
- Determines asymmetry (amblyopia)
5
Q
20/400
A
If the patient cant read 20/400, used printed chart and walk toward them. Record the distance they can see. EX: 20/400 @ 5 feet
6
Q
Beyond 20/400
A
- Count finger
- Hand motion test
- Pen light
If they cant see pen light record as NLP, no light perception
7
Q
VA Charts
A
- Snellen
- Charts for children (pics)
- Tumbling E (nonverbal)
- Landolt C (nonverbal)
8
Q
Pinhole testing
A
Differentiates between decreased vision from refractive error and those caused by pathology
Will indicate if further testing is needed
9
Q
Indication of pinhole testing
A
If VA improves, VA will be corrected by specs
If there is no improvement, VA wont be corrected (Can indicate amblyopia or disease.)