COT Patient History and Ophthalmic Examination Techniques 2 — Questions and Answers
Question 1: Which method is used to test color vision and is most sensitive for detecting red-green deficiencies?
- Farnsworth D-15 panel
- Ishihara pseudoisochromatic plates (Correct answer)
- Amsler grid
- Worth 4-dot test
Correct answer: Ishihara pseudoisochromatic plates
Ishihara pseudoisochromatic plates are the standard screening tool for red-green color vision deficiencies and are highly sensitive for these common defects.
Question 2: When recording extraocular muscle (EOM) function, 'full' motility means the eye moves:
- Only nasally and temporally
- In all nine cardinal positions of gaze without limitation (Correct answer)
- At least 50% of normal range
- To midline in all directions
Correct answer: In all nine cardinal positions of gaze without limitation
Full extraocular muscle motility means the eye moves completely and without restriction or pain through all nine cardinal positions of gaze.
Question 3: Corneal light reflex testing using the Hirschberg method estimates how many prism diopters of deviation for each millimeter of decentration?
- 7 prism diopters (Correct answer)
- 15 prism diopters
- 22 prism diopters
- 30 prism diopters
Correct answer: 7 prism diopters
The Hirschberg test estimates approximately 7 prism diopters of deviation for each 1 mm the corneal light reflex is decentered from the pupil center.
Question 4: Which notation system is used to document the status of the lens during slit-lamp examination?
- LOCS (Lens Opacities Classification System) (Correct answer)
- Snellen notation
- Logmar scale
- Humphrey scoring
Correct answer: LOCS (Lens Opacities Classification System)
The Lens Opacities Classification System (LOCS) provides a standardized grading scale for nuclear, cortical, and posterior subcapsular cataracts.
Question 5: When obtaining a patient's ocular history, asking about prior LASIK or refractive surgery is important primarily because it affects:
- Color vision testing results
- IOP measurements and IOL power calculations (Correct answer)
- Pupil dilation response
- Tear film evaluation
Correct answer: IOP measurements and IOL power calculations
Prior corneal refractive surgery alters corneal curvature and thickness, making standard IOP measurements and IOL power calculations inaccurate without correction factors.
Question 6: The near point of accommodation (NPA) test measures:
- The farthest point at which the eye is focused at rest
- The closest point at which a patient can maintain clear focus (Correct answer)
- The maximum pupil constriction with near targets
- The vergence range for single binocular vision
Correct answer: The closest point at which a patient can maintain clear focus
The near point of accommodation is the closest distance at which a patient can maintain clear, single vision by maximally contracting the ciliary muscle.
COT Patient History and Ophthalmic Examination Techniques 2
Which method is used to test color vision and is most sensitive for detecting red-green deficiencies?