JCAHPO Patient Evaluation 5 — Questions and Answers
Question 1: When recording best-corrected visual acuity as 20/40, this means the patient can see at 20 feet what a person with normal vision can see at:
- 20 feet
- 40 feet (Correct answer)
- 10 feet
- 100 feet
Correct answer: 40 feet
The denominator represents the distance at which a normally sighted person can resolve the same letter that the patient resolves at 20 feet.
Question 2: Pachymetry is performed in the preoperative evaluation for LASIK primarily to measure:
- Axial length of the eye
- Central corneal thickness (Correct answer)
- Anterior chamber depth
- Lens thickness
Correct answer: Central corneal thickness
Central corneal thickness measured by pachymetry is critical to ensure adequate residual stromal bed after refractive ablation, minimizing ectasia risk.
Question 3: A patient with diabetes presents for a dilated fundus exam. Which pupillary dilation agent is most appropriate to use when a short duration of dilation is preferred?
- Atropine 1%
- Scopolamine 0.25%
- Tropicamide 1% (Correct answer)
- Homatropine 5%
Correct answer: Tropicamide 1%
Tropicamide 1% provides rapid, short-acting dilation (4–6 hours) and is the preferred agent when prolonged cycloplegia is undesirable.
Question 4: When performing the swinging flashlight test, a relative afferent pupillary defect (RAPD) is present when the illuminated pupil:
- Constricts briskly when the light swings to that eye
- Dilates or shows less constriction when the light swings to that eye (Correct answer)
- Constricts equally in both eyes
- Dilates only in dim lighting conditions
Correct answer: Dilates or shows less constriction when the light swings to that eye
An RAPD (Marcus Gunn pupil) is identified when the pupil paradoxically dilates as the light swings from the normal eye to the affected eye, indicating reduced afferent input.
Question 5: Which instrument is used at the slit lamp to measure the anterior chamber angle and requires a contact lens?
- Pachymeter
- Gonioscope (Correct answer)
- Keratometer
- Indirect ophthalmoscope
Correct answer: Gonioscope
Gonioscopy uses a mirrored contact lens to redirect the view, allowing visualization of the trabecular meshwork and anterior chamber angle structures.
Question 6: A patient reports that objects appear smaller than they actually are. This symptom is described as:
- Macropsia
- Micropsia (Correct answer)
- Metamorphopsia
- Diplopia
Correct answer: Micropsia
Micropsia is the perception that objects are smaller than their true size and can occur with macular disease, refractive errors, or neurological conditions.
Question 7: Color vision testing with Ishihara pseudoisochromatic plates primarily detects deficiencies in:
- Blue-yellow color discrimination (tritanopia)
- Red-green color discrimination (Correct answer)
- Overall luminance sensitivity
- Scotopic (dark-adapted) vision
Correct answer: Red-green color discrimination
Ishihara plates are designed to detect congenital red-green color deficiencies (protanopia and deuteranopia) and are not sensitive to blue-yellow defects.
JCAHPO Patient Evaluation 5
When recording best-corrected visual acuity as 20/40, this means the patient can see at 20 feet what a person with normal vision can see at: