Question: Which of the following are correct?
1. If visual acuity can be improved by the patient looking through a pinhole, the problem is refractive or ocular, not neurologic in origin.
2. Reduction in the saturation or brightness of colors may be an early sign of optic nerve disease.
3. A relative afferent pupillary defect ipsilateral to visual loss indicates an optic neuropathy or severe retinal disease (in which case the retina looks abnormal on funduscopic examination).
4. If nonorganic visual loss is suspected, normal stereovision indicates 20/20 visual acuity in both eyes.
5. A positive response to the optokinetic nystagmus stimulus indicates a visual acuity of at least 20/400 in the eye tested.
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Correct Answers: All are correct.
Explanation1: “Pearls
- If visual acuity can be improved by the patient looking through a pinhole, the problem is refractive or ocular, not neurologic in origin.
- Reduction in the saturation or brightness of colors may be an early sign of optic nerve disease.
- A relative afferent pupillary defect (RAPD) ipsilateral to visual loss indicates an optic neuropathy or severe retinal disease (in which case the retina looks abnormal on funduscopic examination). Ocular disease, such as corneal abnormalities, cataracts, and most retinal disorders, do not cause RAPDs.
- If nonorganic visual loss is suspected, stereovision should be tested first: normal stereovision implies 20/20 visual acuity in both eyes.
- A positive response to the optokinetic nystagmus stimulus indicates a visual acuity of at least 20/400 in the eye tested.”1
Reference:
1. Neuro-ophthalmology Illustrated-2nd Edition. Biousse V and Newman NJ. 2012. Theme
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