21 Ophthalmic Imaging & Photography Practice Questions & Answers

1. 1. During intravenous fluorescein angiography, which sequence correctly describes the filling phases as the dye reaches the eye?

   • A.Arterial, choroidal flush, venous, arteriovenous, then late
   • B.Choroidal flush, venous, arteriovenous, arterial, then late
   • C.Choroidal flush, arterial, arteriovenous, venous, then late✓ Answer
   • D.Venous, arteriovenous, arterial, choroidal flush, then late

   The dye reaches the choroid first through the short posterior ciliary arteries, producing the patchy choroidal flush, then fills the retinal arterioles, then the capillary bed with laminar flow along the vein walls, then the veins completely; leakage and staining are judged on the late frames after recirculation.

   Source: Fluorescein angiography technique, IJCAHPO Core Criteria Handbook ophthalmic imaging content areaReport a problem with this question

2. 2. In a fundus camera set up for fluorescein angiography, what is the function of the barrier filter?

   • A.Restricts the flash so that only the macula is lit in the early frames
   • B.Transmits the yellow-green light emitted by the dye and blocks reflected blue✓ Answer
   • C.Corrects the photographer's own refractive error at the camera eyepiece
   • D.Delivers the blue excitation light into the eye before the dye is injected

   Fluorescein is excited by blue light and then emits longer-wavelength yellow-green light; the exciter filter supplies the blue illumination and the barrier filter in front of the sensor passes only the emitted yellow-green fluorescence, so reflected blue light does not wash out the image.

   Source: Optics of fluorescein angiography filters, ophthalmic photography practice referencesReport a problem with this question

3. 3. On an angiogram, an area of hyperfluorescence is small and faint early, then becomes larger and brighter with blurred margins on the late frames. Which mechanism does this describe?

   • A.Late staining of an old chorioretinal scar
   • B.Blocked fluorescence from a deep retinal hemorrhage
   • C.Leakage of dye from abnormally permeable vessels✓ Answer
   • D.A window defect from pigment epithelial atrophy

   Leakage is the only cause of hyperfluorescence that both enlarges and intensifies as the study progresses, because dye keeps escaping into tissue or fluid; a window defect is bright early and fades with the dye without changing size, and staining brightens late but stays within fixed borders.

   Source: Interpretation vocabulary of fluorescein angiography, ophthalmic imaging practice referencesReport a problem with this question

4. 4. A patient telephones the morning after a fluorescein angiogram, alarmed that her urine is bright orange. What is the best response?

   • A.Arrange kidney function testing before any further angiography is scheduled
   • B.Reassure her that the kidneys clear the dye and this colour is normal✓ Answer
   • C.Tell her to stop using her eye drops until the colour disappears
   • D.Send her to the emergency department for a suspected dye reaction

   Discoloured urine and transient yellowing of the skin are expected pharmacologic effects of the dye being excreted, not an adverse reaction, so the correct action is reassurance; patients should be told about this before the injection so the call is not frightening.

   Source: Patient education and expected effects of fluorescein, IJCAHPO Core Criteria Handbook ophthalmic imaging content areaReport a problem with this question

5. 5. During the injection the patient reports burning at the venipuncture site and a swelling is rising under the skin. What should be done immediately?

   • A.Elevate the arm and restart in the same vein higher up
   • B.Inject faster to deliver the remaining dose quickly
   • C.Massage the swollen area and continue the early frames
   • D.Stop the injection, tell the physician and apply cold✓ Answer

   Burning with local swelling means the dye is extravasating into the tissue rather than entering the vein; fluorescein outside the vessel is irritating and can cause local tissue damage, so the infusion is stopped at once, the physician is informed and cold is applied.

   Source: Management of intravenous site complications during angiography, ophthalmic assisting practiceReport a problem with this question

6. 6. Shortly after the injection the patient develops widespread hives, wheezing and difficulty speaking. What is the assistant's most appropriate action?

   • A.Send the patient home and telephone them in the morning
   • B.Call the physician at once, start emergency protocol, give oxygen✓ Answer
   • C.Continue late-phase photography and report the rash later
   • D.Give an oral antihistamine and repeat the dye injection

   Urticaria combined with bronchospasm and airway compromise is a true hypersensitivity reaction rather than the common transient nausea, so it is a medical emergency: the assistant stays with the patient, summons the physician, activates the practice emergency plan and supports oxygenation while the emergency cart is brought.

   Source: Adverse dye reaction recognition and emergency response, IJCAHPO Core Criteria Handbook ophthalmic imaging content areaReport a problem with this question

7. 7. When the history is taken before a planned angiogram, which item most directly affects whether and how the study proceeds?

   • A.The date of the patient's most recent spectacle prescription
   • B.A family history of age-related macular degeneration
   • C.A previous reaction to an injected dye or contrast agent✓ Answer
   • D.The brand of soft contact lenses the patient wears daily

   A documented prior reaction to injected dye predicts a higher risk of a repeat reaction and must be reported to the physician before the study, along with asthma, other allergies and relevant liver or kidney disease; consent and a checked emergency cart are part of the same preparation.

   Source: Pre-angiography history, screening and consent, ophthalmic assisting practiceReport a problem with this question

8. 8. Why are colour and red-free (green-filtered) fundus photographs taken before the fluorescein is injected?

   • A.They give a control image on which blood and pigment look dark✓ Answer
   • B.They confirm that dye has already reached the choroidal vessels
   • C.They remove the need to refocus the camera after the injection
   • D.They enlarge the pupil so a weaker flash can be used later

   Green-filtered light is absorbed by blood, so hemorrhages and pigment render dark and superficial retinal detail stands out; taken before any dye is present, these frames also serve as the control that shows whether later brightness is real fluorescence or autofluorescence and pseudofluorescence.

   Source: Baseline colour and red-free photography in angiography protocol, ophthalmic photography practice referencesReport a problem with this question

9. 9. Compared with fluorescein angiography, what does indocyanine green angiography demonstrate better?

   • A.The structures lying behind the iris in an eye with cloudy media
   • B.The endothelial cell mosaic on the back of the cornea
   • C.The retinal nerve fibre layer thickness around the optic disc
   • D.The choroidal vessels, since infrared light passes through pigment✓ Answer

   Indocyanine green absorbs and emits in the near-infrared, which penetrates the retinal pigment epithelium, macular pigment, thin hemorrhage and hazy media, and it is far more strongly protein-bound, so less dye escapes the fenestrated choriocapillaris and the choroidal vasculature is imaged cleanly.

   Source: Indocyanine green angiography principles, ophthalmic imaging practice referencesReport a problem with this question

10. 10. A patient asks how an optical coherence tomography scan produces its image. Which explanation is accurate?

    • A.A green filter photographs the retinal surface in fine detail
    • B.An injected dye outlines the retinal vessels as it circulates
    • C.Reflected light builds a cross-sectional image of the retina✓ Answer
    • D.Sound waves reflected from the retina are timed through a gel

    Optical coherence tomography uses interference between light reflected from tissue and a reference beam to measure echo delay, giving a cross-section of the retinal layers; it is the optical analogue of B-scan ultrasound but needs no dye, no injection and no contact with the eye.

    Source: Principles of optical coherence tomography, IJCAHPO Core Criteria Handbook scanning laser imaging criteriaReport a problem with this question

11. 11. A glaucoma suspect's nerve fibre layer scan returns with low signal strength and one sector coded red; the patient has marked dry eye and blinked during acquisition. What should the technician do?

    • A.Tell the patient the red sector confirms glaucoma damage
    • B.Save the scan and report the nerve fibre layer as thin
    • C.Lubricate, ask for a full blink and repeat the scan✓ Answer
    • D.Dilate the pupil and repeat it as a topography map

    An unstable tear film, blinking or media opacity scatters the beam, lowers signal strength and causes segmentation errors that mimic thinning, so a low-quality scan is repeated after smoothing the tear film rather than saved; interpreting the colour code for the patient is the physician's role.

    Source: Scan quality and artefact recognition in scanning laser imaging, ophthalmic assisting practiceReport a problem with this question

12. 12. On a Placido-disc corneal topography map using the standard colour scale, what does an area shown in warm red-orange indicate?

    • A.It is scarred there, with reduced light transmission
    • B.It is steeper there, with higher dioptric power✓ Answer
    • C.It is flatter there, with lower dioptric power
    • D.It is thinner there, with reduced pachymetry

    The conventional scale codes curvature, not thickness or clarity: warm colours mark steeper radii and therefore higher dioptric power, cool colours mark flatter, lower-power areas, which is why a Placido map alone cannot report corneal thickness.

    Source: Corneal topography map conventions, IJCAHPO Core Criteria Handbook corneal topography criteriaReport a problem with this question

13. 13. A first topography map shows broken, irregular rings across the surface. The patient wears soft contact lenses and has an unstable tear film. What is the most likely explanation?

    • A.Excess dilating drops instilled just before the measurement
    • B.Lens warpage and an unstable tear film distort the reflected rings✓ Answer
    • C.Endothelial cell loss reducing reflection from the surface
    • D.A miscalibrated eyepiece reticle inside the instrument optics

    Placido topography measures the mirror image of the rings reflected off the tear film, so anything that spoils that smooth optical surface, including contact-lens warpage and a dry or broken tear film, produces false irregularity; the fix is a full blink and re-measurement, with lenses left out beforehand.

    Source: Patient preparation for corneal topography, ophthalmic assisting practiceReport a problem with this question

14. 14. Before taking fundus photographs the photographer focuses the crosshair reticle in the camera eyepiece. What does this adjustment accomplish?

    • A.It sets the flash intensity for a heavily pigmented fundus
    • B.It centres the illumination ring inside the patient's pupil
    • C.It offsets the photographer's own refractive error at the eyepiece✓ Answer
    • D.It corrects the patient's refractive error before capture

    The reticle sits in the same plane as the film or sensor, so bringing it sharp with accommodation relaxed, turning from plus toward minus and repeating the setting, cancels the photographer's own refraction; only then does a fundus that looks sharp in the eyepiece record sharp.

    Source: Fundus camera eyepiece focusing technique, ophthalmic photography practice referencesReport a problem with this question

15. 15. A fundus photograph shows a bright crescent of light along one edge of the frame with the opposite side underexposed. What is the most likely cause?

    • A.The camera has been advanced too close to the cornea
    • B.A film of dust has settled on the objective lens
    • C.An upper eyelash has drifted across the light path
    • D.Part of the illumination ring is blocked by the iris✓ Answer

    The illumination enters as a ring through the pupil separately from the imaging path, so if the camera is decentred or the pupil is too small the iris clips one side of that ring and the light spills as a crescent, leaving the opposite side dark; recentring or better dilation fixes it, whereas a central blue-white haze instead means the camera is too close.

    Source: Fundus photography artefact recognition and correction, ophthalmic photography practice referencesReport a problem with this question

16. 16. A patient has a dense vitreous hemorrhage and no view of the fundus. Which study best assesses the retina behind it?

    • A.Placido-disc topography of the anterior corneal surface
    • B.Fluorescein angiography, imaging the dye in late frames
    • C.Wide-angle colour fundus photography of the posterior pole
    • D.B-scan ultrasonography, as sound crosses opaque media✓ Answer

    Every optical method, including photography, angiography and optical coherence tomography, needs light to reach the retina and return, so all of them fail behind blood or a dense cataract; ultrasound uses sound waves transmitted through the opaque media and still shows retinal detachment or a mass.

    Source: Indications for diagnostic ophthalmic ultrasound, IJCAHPO Core Criteria Handbook diagnostic ultrasound content areaReport a problem with this question

17. 17. Which slit-lamp illumination technique is best for photographing posterior capsular opacification after cataract surgery?

    • A.A conical pinpoint beam used in a darkened room
    • B.Sclerotic scatter with the beam placed at the limbus
    • C.Specular reflection off the corneal endothelial surface
    • D.Retroillumination, with light returning from the fundus✓ Answer

    Retroillumination silhouettes an opacity against light reflected back out of the eye, so the capsule wrinkles and deposits appear as dark shapes on a bright orange background; specular reflection is reserved for the endothelial mosaic, sclerotic scatter for subtle corneal haze and a conical beam for cells and flare.

    Source: Slit-lamp illumination techniques for anterior segment photography, IJCAHPO Core Criteria Handbook photography criteriaReport a problem with this question

18. 18. When specular microscopy of the cornea is performed, which layer is imaged and what is assessed?

    • A.The epithelium, assessing punctate surface staining
    • B.The stroma, counting the collagen lamellae present
    • C.The tear film, timing the break-up after a blink
    • D.The endothelium, assessing cell density and shape✓ Answer

    Specular microscopy captures light mirrored at the interface between the endothelium and the aqueous, showing the hexagonal cell mosaic; the report describes cell density along with variation in cell size and shape, and dark drop-like gaps where guttae interrupt the mosaic.

    Source: Specular microscopy of the corneal endothelium, ophthalmic imaging practice referencesReport a problem with this question

19. 19. A child has nystagmus that changes with gaze direction and head posture. Why is video preferred over still photographs for documenting it?

    • A.It records the movement over time, as stills cannot✓ Answer
    • B.It substitutes for the physician's motility examination
    • C.It removes the need to note the gaze position used
    • D.It resolves the retinal surface better than stills do

    A still frame freezes one instant, so it cannot show the waveform, the null position or how the movement changes with gaze; video captures the dynamic finding, and the recording is still labelled with the gaze position and head posture and does not replace the physician's examination.

    Source: Videography for dynamic ocular findings, IJCAHPO Core Criteria Handbook photography and videography content areaReport a problem with this question

20. 20. Reviewing images before they go to the chart, the technician finds fundus photographs of the left eye stored under the label for the right eye. What should be done?

    • A.Leave it, as the physician can tell the eyes apart
    • B.Send them on and add a note at the next visit
    • C.Delete the study and re-photograph the fellow eye
    • D.Correct the laterality before the study is filed✓ Answer

    Laterality is a patient-safety identifier, not a clerical detail, because a mislabelled study can direct treatment or surgery to the wrong eye; the image set is corrected and verified against the patient and encounter before it enters the record.

    Source: Image labelling and record documentation requirements, ophthalmic assisting practiceReport a problem with this question

21. 21. The practice wants to use an identifiable external photograph of a patient in a lecture and on its social media. What is required?

    • A.Approval from the photographer who took it
    • B.A verbal agreement noted in the chart at that visit
    • C.Nothing more, as the image is already on file
    • D.Separate written authorization from the patient✓ Answer

    Clinical photographs are protected health information, and consent to be photographed for care does not extend to teaching, publication or marketing; identifiable images used beyond the patient's own treatment need a separate signed authorization that states the intended use.

    Source: Confidentiality and authorization for use of patient images, ophthalmic assisting ethics and records practiceReport a problem with this question

Practice questions based on the IJCAHPO core certification content areas for the Certified Ophthalmic Assistant and on standard ophthalmic clinical practice references. COA, COT, and COMT are marks of the International Joint Commission on Allied Health Personnel in Ophthalmology; this site is not affiliated with or endorsed by IJCAHPO. Ophthalmic assistants work under the delegation of a supervising ophthalmologist and permitted tasks vary by state and by practice — confirm your own scope, and check the current exam requirements and content outline with IJCAHPO before testing. About IJCAHPO certification →