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COA Certified Ophthalmic Assistant study materials
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COA Certified Ophthalmic Assistant practice questions

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Question 1Clinical and Technical Skills for the Ophthalmic Assistant

When performing Goldmann applanation tonometry, the slit-lamp beam should be set to which configuration before taking the reading?

  1. Narrow beam at 60 degrees, no filter Correct answer.
  2. Full circular beam with the diffuse filter
  3. Wide beam at 45 degrees, cobalt blue filter
  4. Medium beam at 10 degrees with the red-free filter

Explanation

Standard technique uses the widest possible illumination angle with the narrowest beam, classically a narrow slit at roughly 60 degrees, so the fluorescein semicircles are illuminated without glare from the surrounding cornea. The cobalt blue filter is used for fluorescein evaluation of the tear film but is not the standard setting for applanation mires.

Question 2Clinical and Technical Skills for the Ophthalmic Assistant

A patient's manifest refraction is -3.00 sphere in the right eye. Which lens power should be used in the trial frame to verify that the patient is not overminused?

  1. +0.25 sphere added to the -3.00
  2. -3.25 sphere
  3. -2.75 sphere Correct answer.
  4. Plano with a pinhole

Explanation

A duochrome or plus/minus verification step checks whether the patient accepts less minus (or more plus). Presenting -2.75 sphere tests whether the patient still sees clearly with 0.25 D less minus, which would indicate overminusing. If acuity holds, the original -3.00 was likely too strong.

Question 3Clinical and Technical Skills for the Ophthalmic Assistant

Which measurement is obtained by having the patient fixate on a distant target while a ruler is placed at the lateral canthus?

  1. Pupillary distance at distance Correct answer.
  2. Palpebral fissure height
  3. Pupillary distance at near
  4. Levator function

Explanation

Distance pupillary distance is measured with the patient viewing a target at 6 meters or beyond, so accommodation does not converge the pupils inward. Near PD is measured with a near target and is typically 2 to 4 mm smaller. Palpebral fissure height and levator function are eyelid measurements unrelated to pupillary distance.

Question 4Clinical and Technical Skills for the Ophthalmic Assistant

During Goldmann perimetry, the technician notices the patient's responses are consistently delayed and the isopters appear constricted compared with a prior field. What is the most appropriate first action?

  1. Reduce the target size to improve patient attention
  2. Repeat the test after confirming fixation, refraction, and patient understanding Correct answer.
  3. Document the field as reliable and notify the physician
  4. Switch to a screening program to save time

Explanation

Artifactual constriction commonly results from poor fixation, uncorrected refractive error, or misunderstanding of the instructions. Before interpreting a field as abnormal, the technician should verify these factors and repeat testing. Documentation alone or altering the strategy does not address the underlying cause.

Question 5Clinical and Technical Skills for the Ophthalmic Assistant

A patient reports sudden onset of a curtain-like shadow over the superior visual field of one eye. Which finding should prompt immediate escalation?

  1. Bilateral dry eye symptoms
  2. Chronic open-angle glaucoma with stable fields
  3. Floaters that have been stable for years
  4. A new posterior vitreous detachment with a retinal tear Correct answer.

Explanation

A curtain or shadow across the visual field suggests retinal detachment, especially when accompanied by new flashes or floaters. A retinal tear identified on examination requires urgent referral for laser or surgical management. Stable chronic conditions and dry eye do not produce an acute curtain defect.

Question 6Clinical and Technical Skills for the Ophthalmic Assistant

A 62-year-old patient with a known cataract reports glare and halos around lights at night. Which test best quantifies the impact of these symptoms on visual function?

  1. Ishihara color plates
  2. Contrast sensitivity testing Correct answer.
  3. Amsler grid
  4. Stereopsis testing

Explanation

Contrast sensitivity measures the ability to detect low-contrast targets and is particularly sensitive to cataract-related glare and reduced image quality. The Amsler grid assesses macular distortion, Ishihara plates assess color vision, and stereopsis assesses binocular depth perception, none of which directly quantify glare-related functional loss.

Question 7Clinical and Technical Skills for the Ophthalmic Assistant

When instilling eye drops, which technique best minimizes systemic absorption of a beta-blocker?

  1. Punctal occlusion for one to two minutes after instillation Correct answer.
  2. Having the patient lie flat for five minutes
  3. Rapid blinking immediately after instillation
  4. Instilling the drop onto the closed lid margin

Explanation

Occluding the puncta reduces drainage into the nasolacrimal duct and subsequent absorption through the nasal mucosa, lowering systemic exposure. Blinking accelerates drainage, and placing drops on the closed lid or lying flat does not impede nasolacrimal flow.

Question 8Clinical and Technical Skills for the Ophthalmic Assistant

Which instrument uses a split-image principle to measure corneal curvature along two meridians?

  1. Tonometer
  2. Pachymeter
  3. Keratometer Correct answer.
  4. Autorefractor

Explanation

A keratometer projects mires and uses a split-image doubling system to measure corneal curvature, typically along two perpendicular meridians to determine astigmatism. A pachymeter measures corneal thickness, a tonometer measures intraocular pressure, and an autorefractor estimates refractive error.

Question 9Clinical and Technical Skills for the Ophthalmic Assistant

During a visual acuity test, a patient reads the 20/40 line with three errors. How should the technician record the acuity?

  1. 20/40
  2. 20/50 plus three
  3. 20/40 minus three Correct answer.
  4. 20/40 with pinhole

Explanation

When a patient misses letters on a line, the standard convention is to record the line value with a minus and the number of missed letters. Three missed letters on the 20/40 line is recorded as 20/40 minus three. Recording a plus value on the next line is the convention used when the patient reads additional letters beyond a line.

Question 10Clinical and Technical Skills for the Ophthalmic Assistant

Which color plate test is designed to detect blue-yellow (tritan) defects in addition to red-green defects?

  1. Hardy-Rand-Rittler plates Correct answer.
  2. Ishihara plates
  3. Farnsworth-Munsell 100-hue test
  4. Anomaloscope

Explanation

Hardy-Rand-Rittler plates use symbols that are graded for both red-green and blue-yellow defects, making them more comprehensive than Ishihara plates. The Farnsworth-Munsell 100-hue test provides detailed hue discrimination but is not a plate test, and the anomaloscope is used for precise red-green matching.

Question 11Clinical and Technical Skills for the Ophthalmic Assistant

A patient with a suspected corneal abrasion has a positive Seidel test. What does this indicate?

  1. A retained foreign body
  2. A superficial epithelial defect only
  3. A full-thickness corneal perforation with aqueous leakage Correct answer.
  4. A normal tear film

Explanation

The Seidel test uses fluorescein to detect a stream of aqueous leaking through a corneal wound. A positive result indicates full-thickness perforation with leakage, which requires urgent ophthalmic management. A superficial abrasion would stain but not show a streaming leak.

Question 12Clinical and Technical Skills for the Ophthalmic Assistant

Which test is most appropriate for assessing binocular alignment when a patient reports double vision?

  1. Swinging flashlight test
  2. Schirmer test
  3. Gonioscopy
  4. Cover-uncover test Correct answer.

Explanation

The cover-uncover test detects manifest and latent deviations by observing eye movement when one eye is covered and uncovered. The swinging flashlight test assesses pupillary light reflex pathways, the Schirmer test measures tear production, and gonioscopy evaluates the anterior chamber angle.

Question 13Clinical and Technical Skills for the Ophthalmic Assistant

A patient's intraocular pressure reads 24 mmHg with a Goldmann tonometer, but the cornea has a central thickness of 620 micrometers. How should this be interpreted?

  1. The true pressure is likely lower than the measured value Correct answer.
  2. The reading should be discarded entirely
  3. The true pressure is likely higher than the measured value
  4. Corneal thickness does not affect Goldmann readings

Explanation

Thicker corneas resist applanation, so Goldmann tonometry tends to overestimate pressure in eyes with thick corneas. A measurement of 24 mmHg with a 620-micrometer cornea likely overstates the true intraocular pressure. Pachymetry data are used to adjust interpretation, not to invalidate the reading.

Question 14Clinical and Technical Skills for the Ophthalmic Assistant

Which technique is used to measure the amplitude of accommodation?

  1. Bagolini striated lenses
  2. Worth four-dot test
  3. Cover test at distance
  4. Push-up method with a near card Correct answer.

Explanation

The push-up method moves a near target toward the patient until it blurs, and the amplitude is calculated from the distance at which blur occurs. The cover test, Worth four-dot test, and Bagolini lenses assess alignment or fusion rather than accommodation.

Question 15Clinical and Technical Skills for the Ophthalmic Assistant

During a slit-lamp examination, which illumination technique is best for evaluating corneal thickness and depth of a lesion?

  1. Retroillumination
  2. Diffuse illumination
  3. Optical section with a narrow beam Correct answer.
  4. Sclerotic scatter

Explanation

An optical section uses a narrow slit beam to create a cross-sectional view of the cornea, allowing the examiner to judge thickness and lesion depth. Diffuse illumination gives an overview, sclerotic scatter highlights opacities, and retroillumination silhouettes lesions against a reflected background.

Question 16Clinical and Technical Skills for the Ophthalmic Assistant

Which structure is assessed by gonioscopy?

  1. Iridocorneal angle Correct answer.
  2. Corneal endothelium
  3. Optic nerve head
  4. Lens capsule

Explanation

Gonioscopy uses a mirrored contact lens to visualize the iridocorneal angle, which is otherwise hidden by total internal reflection at the cornea-air interface. It is essential for classifying open-angle versus closed-angle glaucoma. The corneal endothelium, lens capsule, and optic nerve head are evaluated with other techniques.

Question 17Clinical and Technical Skills for the Ophthalmic Assistant

A patient scheduled for A-scan biometry has a history of prior corneal refractive surgery. Why is this clinically important?

  1. Refractive surgery increases the risk of pupillary block
  2. Refractive surgery alters the assumed keratometric value used in intraocular lens calculation Correct answer.
  3. Refractive surgery eliminates the need for biometry
  4. Refractive surgery changes the axial length measurement to zero

Explanation

A-scan biometry relies on an assumed corneal power or measured keratometry to calculate intraocular lens power. Prior refractive surgery changes the corneal curvature and its relationship to true power, so standard formulas can produce inaccurate lens predictions. Specialized formulas and additional measurements are often needed.

Question 18Clinical and Technical Skills for the Ophthalmic Assistant

Which test is used to evaluate tear film breakup time?

  1. Schirmer test with anesthesia
  2. Tear osmolarity measurement
  3. Jones dye test
  4. Instillation of fluorescein followed by observation with a cobalt blue filter Correct answer.

Explanation

Tear breakup time is measured by instilling fluorescein, having the patient refrain from blinking, and timing the appearance of dry spots under cobalt blue illumination. The Schirmer test measures tear volume, osmolarity measures concentration, and the Jones test evaluates tear drainage.

Question 19Clinical and Technical Skills for the Ophthalmic Assistant

A patient's confrontation visual field shows a defect respecting the vertical midline in both eyes. What does this pattern suggest?

  1. A retinal detachment in one eye
  2. A corneal abrasion
  3. A chiasmal or retrochiasmal lesion Correct answer.
  4. Optic neuritis in one eye

Explanation

A homonymous defect that respects the vertical midline localizes to the optic chiasm or retrochiasmal visual pathways. Unilateral retinal or optic nerve disease produces defects that respect the horizontal midline or affect one eye only. Corneal abrasions cause localized surface symptoms rather than a hemianopic pattern.

Question 20Clinical and Technical Skills for the Ophthalmic Assistant

Which step is essential before performing applanation tonometry on a patient with a known corneal abrasion?

  1. Confirm the abrasion has healed or use an alternative method Correct answer.
  2. Instill a topical anesthetic and proceed as usual
  3. Increase the fluorescein concentration
  4. Apply pressure to the globe first

Explanation

Applanation over an active epithelial defect risks worsening the injury and introducing infection. The technician should confirm healing or use an alternative tonometry method as directed by the physician. Proceeding as usual or increasing fluorescein does not address the risk.

Question 21Clinical and Technical Skills for the Ophthalmic Assistant

Which measurement describes the distance from the anterior corneal surface to the retinal pigment epithelium?

  1. Corneal diameter
  2. Axial length Correct answer.
  3. Lens thickness
  4. Anterior chamber depth

Explanation

Axial length is the distance from the corneal apex to the retinal pigment epithelium or fovea and is a key input for intraocular lens power calculation. Anterior chamber depth, lens thickness, and corneal diameter are component measurements that do not represent the full eye length.

Question 22Clinical and Technical Skills for the Ophthalmic Assistant

A patient's pupil does not constrict when light is swung from the unaffected eye to the affected eye. What is this finding called?

  1. Argyll Robertson pupil
  2. Adie tonic pupil
  3. Relative afferent pupillary defect Correct answer.
  4. Horner syndrome

Explanation

A relative afferent pupillary defect occurs when the affected eye transmits less light signal, causing the pupil to dilate when light swings to that eye. Argyll Robertson pupils are small and irregular with light-near dissociation, Adie pupils are tonic and dilated, and Horner syndrome involves ptosis and miosis.

Question 23Clinical and Technical Skills for the Ophthalmic Assistant

Which precaution is most important when performing a Schirmer test without anesthesia?

  1. Place the paper over the cornea
  2. Have the patient keep the eyes open and blink frequently
  3. Avoid touching the cornea with the filter paper Correct answer.
  4. Instill a mydriatic before testing

Explanation

The filter paper is placed in the lower fornix and should not contact the cornea, which would cause reflex tearing and invalidate the result. Mydriatics are unrelated, frequent blinking alters the measurement, and paper is never placed on the cornea.

Question 24Clinical and Technical Skills for the Ophthalmic Assistant

A patient has a manifest refraction of +1.00 sphere with a visual acuity of 20/25. Which finding would suggest that the patient is accommodating excessively?

  1. Rejection of plus and acceptance of more minus Correct answer.
  2. Stable acuity with a pinhole
  3. Equal acuity with both eyes
  4. Acceptance of more plus on fogging

Explanation

Excessive accommodation, or overaccommodation, causes the patient to reject plus lenses and accept more minus to maintain clarity. Fogging techniques are used to relax accommodation and reveal the true refractive state. Stable pinhole acuity and equal acuity do not specifically indicate overaccommodation.

Question 25Clinical and Technical Skills for the Ophthalmic Assistant

Which technique is used to assess ocular motility in the six cardinal positions?

  1. Performing a Schirmer test in each gaze
  2. Asking the patient to follow a target through the cardinal gazes Correct answer.
  3. Using a pachymeter in each gaze
  4. Measuring intraocular pressure in each gaze

Explanation

Ocular motility testing involves having the patient follow a target into the six cardinal positions of gaze to evaluate each extraocular muscle. Pressure, tear production, and corneal thickness are unrelated to motility assessment.

Question 26Clinical and Technical Skills for the Ophthalmic Assistant

A patient is being fitted with rigid gas-permeable contact lenses. Which instrument is used to measure the base curve of the lens and verify it against the ordered specification?

  1. Keratometer
  2. Pachymeter
  3. Lensometer (focimeter)
  4. Radiuscope Correct answer.

Explanation

A radiuscope measures the radius of curvature of a contact lens surface, allowing the base curve of a rigid lens to be verified. A lensometer measures refractive power, not curvature, so it cannot confirm base curve.

Question 27Clinical and Technical Skills for the Ophthalmic Assistant

A technician is preparing to perform Goldmann applanation tonometry. Which agent is instilled before measurement to anesthetize the cornea and provide fluorescein for the mires?

  1. A combination of proparacaine and fluorescein Correct answer.
  2. Tropicamide 1%
  3. Proparacaine 0.5% alone
  4. Pilocarpine 2%

Explanation

Applanation tonometry requires corneal anesthesia to prevent discomfort and fluorescein to make the tear film mires visible under cobalt blue light. A combined anesthetic-fluorescein drop provides both in one instillation.

Question 28Clinical and Technical Skills for the Ophthalmic Assistant

A patient is instructed to look at a distant target while the technician alternately covers each eye and observes the uncovered eye for movement. Which function is being assessed?

  1. Near point of convergence
  2. Worth 4-dot test
  3. Cover test for strabismus Correct answer.
  4. Stereopsis

Explanation

The cover test detects manifest and latent deviations by observing movement of the uncovered eye as fixation is shifted. Movement indicates that the eye was not aligned with the fixation target when uncovered.

Question 29Clinical and Technical Skills for the Ophthalmic Assistant

During retinoscopy, the technician notes that the streak moves in the same direction as the mirror is tilted. What does this indicate, and how is it neutralized?

  1. Against motion, neutralized with a prism
  2. With motion, neutralized with plus lenses Correct answer.
  3. Against motion, neutralized with plus lenses
  4. With motion, neutralized with minus lenses

Explanation

With motion in retinoscopy indicates hyperopia or undercorrection and is neutralized by adding plus lenses until the reflex becomes neutral. Against motion indicates myopia and is neutralized with minus lenses.

Question 30Clinical and Technical Skills for the Ophthalmic Assistant

A patient reports a sudden onset of floaters and flashes of light. Which additional symptom most warrants urgent dilated fundus examination?

  1. Mild itching of the eyelids
  2. Gradual loss of near vision
  3. A curtain or shadow across the visual field Correct answer.
  4. Increased tear production

Explanation

Floaters and flashes with a curtain or shadow suggest a possible retinal detachment, which is an ocular emergency requiring prompt dilated examination. The other symptoms are not associated with retinal tears or detachment.

Question 31Clinical and Technical Skills for the Ophthalmic Assistant

When performing a dilated fundus examination, which drop is used primarily to paralyze the ciliary muscle and prevent accommodation?

  1. Fluorescein sodium
  2. Naphazoline 0.1%
  3. Cyclopentolate 1% Correct answer.
  4. Phenylephrine 2.5%

Explanation

Cyclopentolate is a cycloplegic that blocks the parasympathetic supply to the ciliary muscle, temporarily paralyzing accommodation. Phenylephrine dilates the pupil without cycloplegia.

Question 32Clinical and Technical Skills for the Ophthalmic Assistant

A patient's visual acuity is recorded as 20/200 in the right eye. What does this value indicate?

  1. The patient sees at 200 feet what a normal eye sees at 20 feet
  2. The patient requires a 200-diopter correction
  3. The patient sees at 20 feet what a normal eye sees at 200 feet Correct answer.
  4. The patient has 200 degrees of visual field

Explanation

The Snellen fraction compares the test distance to the distance at which a person with normal acuity could identify the same optotype. A value of 20/200 means the patient needs to be at 20 feet to see what a normal eye sees at 200 feet.

Question 33Clinical and Technical Skills for the Ophthalmic Assistant

A technician is about to perform a dilated fundus examination and must check for a history of narrow angles. Which finding on the patient's record is most relevant?

  1. A prior cataract surgery in the fellow eye
  2. A family history of glaucoma
  3. A history of contact lens wear
  4. A shallow anterior chamber on slit-lamp evaluation Correct answer.

Explanation

A shallow anterior chamber suggests a narrow angle and increases the risk of angle-closure glaucoma after pupil dilation. The technician should alert the physician before instilling mydriatic drops.

Question 34Clinical and Technical Skills for the Ophthalmic Assistant

Which test uses a series of progressively finer gratings to estimate visual acuity in a patient who cannot read letters?

  1. Ishihara plates
  2. Amsler grid
  3. Teller acuity cards Correct answer.
  4. Contrast sensitivity chart

Explanation

Teller acuity cards present grating patterns of varying spatial frequency and are used to estimate acuity in preverbal or nonverbal patients. They rely on preferential looking rather than letter recognition.

Question 35Clinical and Technical Skills for the Ophthalmic Assistant

A patient is scheduled for a visual field test using a Humphrey perimeter. Which instruction is most important to give before the test begins?

  1. Look toward each light as it appears
  2. Keep the tested eye closed throughout the test
  3. Blink only when the technician instructs
  4. Fixate on the central target and respond only when the light is seen Correct answer.

Explanation

Reliable visual field testing depends on steady central fixation and accurate responses to perceived stimuli. Looking toward the lights or moving the eye invalidates the results.

Question 36Clinical and Technical Skills for the Ophthalmic Assistant

A patient's manifest refraction is plano in the right eye with a visual acuity of 20/20. Which additional measurement would best detect a latent hyperopia that is masked by accommodation?

  1. Keratometry
  2. Cycloplegic refraction Correct answer.
  3. Pachymetry
  4. Gonioscopy

Explanation

Cycloplegic refraction relaxes accommodation so latent hyperopia is not masked by the patient's accommodative effort. A manifest refraction alone may underestimate hyperopia in a young patient.

Question 37Clinical and Technical Skills for the Ophthalmic Assistant

Which instrument is used to measure the axial length of the eye before cataract surgery?

  1. Optic coherence tomography
  2. B-scan ultrasonography
  3. Specular microscopy
  4. A-scan ultrasonography Correct answer.

Explanation

A-scan ultrasonography measures axial length along the visual axis and is used with keratometry to calculate intraocular lens power. B-scan provides a two-dimensional image rather than a precise axial measurement.

Question 38Clinical and Technical Skills for the Ophthalmic Assistant

A patient is being evaluated for dry eye. Which finding on the tear film breakup time test is considered abnormal?

  1. A breakup time of less than 10 seconds Correct answer.
  2. A breakup time of 20 seconds
  3. A breakup time of 25 seconds
  4. A breakup time of 15 seconds

Explanation

A tear film breakup time of less than 10 seconds suggests an unstable tear film and is consistent with dry eye. Longer breakup times indicate a more stable tear film.

Question 39Clinical and Technical Skills for the Ophthalmic Assistant

A patient with a known allergy to topical anesthetics requires a Schirmer test. Which alternative approach is most appropriate?

  1. Use a cotton swab instead of filter paper
  2. Instill a stronger anesthetic
  3. Perform the test without anesthesia using only the filter paper strip Correct answer.
  4. Skip the test entirely

Explanation

The Schirmer test can be performed without anesthesia, although it may cause mild irritation. Using a stronger anesthetic or altering the paper would not address the allergy and could invalidate the test.

Question 40Clinical and Technical Skills for the Ophthalmic Assistant

Which structure is directly visualized when performing direct ophthalmoscopy?

  1. The corneal endothelium
  2. The lacrimal drainage system
  3. The optic disc and retinal vessels Correct answer.
  4. The anterior chamber angle

Explanation

Direct ophthalmoscopy provides a magnified view of the posterior pole, including the optic disc, macula, and retinal vessels. The anterior chamber angle and corneal endothelium require other instruments.

Question 41Clinical and Technical Skills for the Ophthalmic Assistant

A patient is being fitted for a soft contact lens. Which measurement is most important to determine the appropriate lens diameter?

  1. Central corneal thickness
  2. Axial length
  3. Horizontal visible iris diameter Correct answer.
  4. Intraocular pressure

Explanation

Horizontal visible iris diameter helps determine the appropriate soft lens diameter so the lens covers the cornea adequately. Corneal thickness, axial length, and intraocular pressure do not guide lens diameter selection.

Question 42Clinical and Technical Skills for the Ophthalmic Assistant

Which test is used to detect a relative afferent pupillary defect?

  1. Worth 4-dot test
  2. Swinging flashlight test Correct answer.
  3. Bagolini striated lens test
  4. Cover-uncover test

Explanation

The swinging flashlight test compares the pupillary response when light is alternated between eyes. A pupil that dilates when light is swung to it indicates a relative afferent pupillary defect.

Question 43Clinical and Technical Skills for the Ophthalmic Assistant

A patient's anterior chamber is being evaluated with a slit lamp. Which illumination technique provides an optical cross-section of the cornea and lens?

  1. Diffuse illumination
  2. Retroillumination
  3. Sclerotic scatter
  4. Optic section (narrow beam) Correct answer.

Explanation

A narrow slit beam creates an optic section that shows the depth and layers of the cornea and lens. Diffuse illumination and retroillumination do not provide a cross-sectional view.

Question 44Clinical and Technical Skills for the Ophthalmic Assistant

A patient reports intermittent double vision that resolves when one eye is covered. Which finding is most consistent with a decompensating phoria?

  1. A constant esotropia in primary gaze
  2. A normal cover test with no movement
  3. A visual acuity of 20/20 in each eye
  4. A tropia present only on dissociation testing Correct answer.

Explanation

A phoria that decompensates becomes manifest under dissociation and produces intermittent diplopia. Constant strabismus would cause diplopia that persists without dissociation, and normal cover testing would not explain the symptom.

Question 45Clinical and Technical Skills for the Ophthalmic Assistant

Which agent is used to stain the cornea for detection of epithelial defects?

  1. Methylene blue
  2. Indocyanine green
  3. Rose bengal only
  4. Fluorescein sodium Correct answer.

Explanation

Fluorescein sodium stains areas where corneal epithelium is absent and is viewed under cobalt blue light. It is the standard dye for identifying epithelial defects.

Question 46Clinical and Technical Skills for the Ophthalmic Assistant

A patient is scheduled for a fluorescein angiogram. Which history item is most important to obtain before the procedure?

  1. History of seasonal allergies
  2. Family history of diabetes
  3. Previous allergic reaction to fluorescein or iodine Correct answer.
  4. Use of reading glasses

Explanation

Fluorescein angiography can cause allergic reactions, including anaphylaxis, so a prior reaction to fluorescein or iodine must be identified beforehand. The other history items do not directly affect angiogram safety.

Question 47Clinical and Technical Skills for the Ophthalmic Assistant

Which measurement is obtained with a keratometer?

  1. Corneal curvature in two principal meridians Correct answer.
  2. Intraocular pressure
  3. Corneal endothelial cell density
  4. Axial length of the eye

Explanation

A keratometer measures the curvature of the anterior corneal surface along two principal meridians, providing keratometry readings. It does not measure axial length, endothelial density, or intraocular pressure.

Question 48Clinical and Technical Skills for the Ophthalmic Assistant

A patient with a suspected retinal detachment is being evaluated. Which imaging modality provides a cross-sectional view of the retina and is useful for detecting subretinal fluid?

  1. Keratometry
  2. Optical coherence tomography Correct answer.
  3. A-scan ultrasonography
  4. Gonioscopy

Explanation

Optical coherence tomography provides high-resolution cross-sectional images of the retina and can show subretinal fluid. A-scan gives axial length, keratometry gives corneal curvature, and gonioscopy evaluates the angle.

Question 49Clinical and Technical Skills for the Ophthalmic Assistant

A technician is performing a confrontation visual field test. Which technique is used to compare the patient's field with the examiner's field?

  1. The examiner and patient face each other and the examiner moves a target into the patient's field Correct answer.
  2. The patient stares at a central target while a computer presents lights
  3. The patient identifies colored plates
  4. The patient reads letters at increasing distances

Explanation

Confrontation testing compares the patient's visual field with the examiner's by moving a target from the periphery toward the center while both face each other. Computerized perimetry and color plate testing assess different functions.

Question 50Clinical and Technical Skills for the Ophthalmic Assistant

A patient is being evaluated for a corneal ulcer. Which finding on slit-lamp examination most suggests an active infection?

  1. A normal tear film breakup time
  2. A white infiltrate with surrounding haze and an epithelial defect Correct answer.
  3. A pinguecula on the conjunctiva
  4. A clear cornea with no staining

Explanation

An active corneal ulcer typically appears as a white infiltrate with surrounding haze and an overlying epithelial defect that stains with fluorescein. Clear corneas, pingueculae, and normal tear breakup do not indicate active infection.