BRS Evaluation of Visual Impairment 5 — Questions and Answers
Question 1: A rehabilitation specialist conducts a functional vision assessment and a clinical low vision evaluation. What is the primary distinction between these two assessments?
- The clinical evaluation uses standard acuity charts while the functional assessment examines how vision impacts daily tasks and independence (Correct answer)
- The functional assessment is performed only by ophthalmologists and the clinical evaluation by BRS specialists
- The clinical evaluation focuses on rehabilitation goals while the functional assessment focuses only on optical prescriptions
- Both assessments are identical in scope and differ only in setting
Correct answer: The clinical evaluation uses standard acuity charts while the functional assessment examines how vision impacts daily tasks and independence
Clinical low vision evaluation measures visual parameters (acuity, field, contrast), while functional vision assessment evaluates how those parameters impact real-world daily activities.
Question 2: When using the ETDRS (Early Treatment Diabetic Retinopathy Study) chart, acuity is reported as:
- A decimal fraction based on reading speed at 4 meters
- A letter score (number of letters read correctly) and a logMAR acuity value (Correct answer)
- A Snellen fraction only, measured at 20 feet
- A contrast sensitivity function expressed as log units
Correct answer: A letter score (number of letters read correctly) and a logMAR acuity value
The ETDRS chart yields a letter score (typically out of 100) and a corresponding logMAR value, providing a more precise and statistically reliable acuity measurement than traditional Snellen charts.
Question 3: A client with age-related macular degeneration (AMD) uses a head-mounted electronic magnifier with image enhancement features. During evaluation, the BRS specialist should assess:
- Only the maximum magnification level the device can provide
- Device comfort, field of view at functional magnification, image processing preferences, and task performance (Correct answer)
- Whether the device meets Medicare reimbursement criteria before trialing it clinically
- Only the client's near acuity at the lowest magnification setting
Correct answer: Device comfort, field of view at functional magnification, image processing preferences, and task performance
A thorough device trial must assess comfort, adequate field of view at the magnification needed, image processing preferences (contrast, color), and whether the client can complete target tasks.
Question 4: Binocular visual acuity in patients with low vision is often better, equal to, or worse than monocular acuity in the better eye. Which pattern most commonly occurs in patients with bilateral central scotomas?
- Binocular acuity is consistently 2 lines better than the better eye monocularly
- Binocular acuity is often similar to or slightly better than monocular, but significant binocular inhibition can occur (Correct answer)
- Binocular acuity is always worse due to interocular suppression of both scotomas
- Binocular acuity is unrelated to monocular acuity in any low vision condition
Correct answer: Binocular acuity is often similar to or slightly better than monocular, but significant binocular inhibition can occur
Binocular performance in bilateral low vision can be similar to or slightly better than the better eye monocularly, but interocular rivalry or misaligned PRLs can sometimes cause binocular inhibition.
Question 5: A BRS specialist evaluates a client post-stroke who has left homonymous hemianopia. To assist with reading evaluation, the specialist should consider that this client will most likely struggle with:
- Reading the beginning of lines because the left field loss eliminates return sweep cues (Correct answer)
- Reading the end of lines because they cannot see text in the right visual field
- Distinguishing colors in both visual fields equally
- Reading only under low-luminance conditions
Correct answer: Reading the beginning of lines because the left field loss eliminates return sweep cues
Left homonymous hemianopia impairs the return sweep from the right end of a line back to the left margin, making line-finding the primary reading difficulty.
Question 6: When evaluating glare sensitivity in a client with cataracts, which test is most appropriate to quantify disabling glare?
- Pelli-Robson Contrast Sensitivity Chart under standard room lighting
- Brightness Acuity Tester (BAT) measured before and after exposure to a glare source (Correct answer)
- Goldmann perimetry under photopic conditions
- Farnsworth-Munsell 100-Hue Color Test
Correct answer: Brightness Acuity Tester (BAT) measured before and after exposure to a glare source
The Brightness Acuity Tester (BAT) quantifies disabling glare by measuring visual acuity before and after exposure to a controlled bright light source, directly simulating real-world glare.
Question 7: A BRS specialist observes that a pediatric client with albinism demonstrates nystagmus that dampens when the child adopts a chin-down head posture. This null point observation indicates the specialist should:
- Refer for immediate surgical correction of the nystagmus before any rehabilitation
- Consider the null point posture when recommending optical and environmental modifications and liaising with the educational team (Correct answer)
- Document the nystagmus and defer all intervention until adulthood
- Discourage the head posture because it strains the cervical spine
Correct answer: Consider the null point posture when recommending optical and environmental modifications and liaising with the educational team
The null point is the gaze direction where nystagmus is minimized; rehabilitation specialists should incorporate this posture into device recommendations, classroom seating, and environmental setup.
BRS Evaluation of Visual Impairment 5
A rehabilitation specialist conducts a functional vision assessment and a clinical low vision evaluation.
What is the primary distinction between these two assessments?