AOC AOC Diagnostic Testing and Instrumentation 1 — Questions and Answers
Question 1: Which instrument is used in orthoptics to measure and treat strabismus by presenting different images to each eye simultaneously?
- Slit lamp
- Synoptophore (major amblyoscope) (Correct answer)
- Perimeter
- Fundus camera
Correct answer: Synoptophore (major amblyoscope)
The synoptophore (major amblyoscope) projects separate targets to each eye, allowing measurement of strabismus angles and assessment of binocular vision.
Question 2: When performing visual acuity testing in young children unable to read letters, which test is most commonly used?
- Snellen chart
- LogMAR chart
- Lea symbols or Teller acuity cards (Correct answer)
- Color plate testing
Correct answer: Lea symbols or Teller acuity cards
Lea symbols and Teller acuity cards are developmentally appropriate tools for assessing visual acuity in preverbal or young children.
Question 3: Which test uses a red glass placed before one eye to evaluate ocular alignment and measure diplopia?
- Cover test
- Maddox rod test
- Red glass test (Lancaster or Hess screen) (Correct answer)
- Bagolini striated lens test
Correct answer: Red glass test (Lancaster or Hess screen)
The red glass test dissociates the two eyes using a red filter and a light source to map diplopia fields and estimate deviation.
Question 4: The Maddox rod test is used primarily to measure which type of deviation?
- Vertical tropias only
- Horizontal and vertical phorias (Correct answer)
- Cyclodeviation only
- Intermittent exotropia distance angle
Correct answer: Horizontal and vertical phorias
The Maddox rod converts a point light source into a streak, dissociating the eyes to reveal and measure horizontal and vertical phorias.
Question 5: Visual field testing is performed in the orthoptic setting most commonly using which method to map peripheral function?
- OCT imaging
- Confrontation field testing or automated perimetry (Correct answer)
- Fundoscopy
- Electroretinography
Correct answer: Confrontation field testing or automated perimetry
Confrontation field testing and automated perimetry (e.g., Humphrey) are standard methods to map the peripheral and central visual fields.
Question 6: Which chart design measures visual acuity on a logarithmic scale, making it preferred for research and low vision assessment?
- Snellen chart
- Jaeger chart
- LogMAR chart (e.g., ETDRS) (Correct answer)
- Allen picture chart
Correct answer: LogMAR chart (e.g., ETDRS)
The LogMAR chart (such as the ETDRS chart) uses equal letter spacing and progression on a logarithmic scale, providing more precise acuity measurements.
AOC AOC Diagnostic Testing and Instrumentation 1
Which instrument is used in orthoptics to measure and treat strabismus by presenting different images to each eye simultaneously?