Practice Test GeeksCOT - Certified Ophthalmic Technician Practice Test
← All COT Flashcard Decks

Ophthalmic Imaging and Photography Flashcards

7 cards from real COT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Ophthalmic Imaging and Photography flashcards as text

  1. Enhanced depth imaging (EDI) OCT is specifically designed to improve visualization of which ocular structure?

    Answer: Choroid

    EDI-OCT inverts the sensitivity roll-off to place the zero-delay line deeper, improving signal from the choroid and sub-RPE layers.

  2. Which grading scale is most commonly used to standardize documentation of diabetic retinopathy severity from fundus photographs?

    Answer: Early Treatment Diabetic Retinopathy Study (ETDRS) scale

    The ETDRS severity scale, developed from the landmark clinical trial, provides a standardized 13-level grading system for diabetic retinopathy.

  3. In fluorescein angiography, 'window defect' hyperfluorescence is caused by:

    Answer: Loss of RPE blocking pigment revealing background choroidal fluorescence

    Window defects occur when RPE atrophy or thinning removes the normal blocking layer, allowing background choroidal fluorescence to shine through.

  4. A patient's OCT shows a 'double hump' or 'W-shape' reflectivity profile in the outer retina. This pattern is most associated with:

    Answer: Normal foveal pit anatomy

    The normal foveal OCT profile shows a central pit flanked by the thicker parafoveal retina, creating a characteristic 'W' or double-hump appearance.

  5. Which photographic technique is used to map the anterior segment angle and document angle-closure risk?

    Answer: Scheimpflug imaging (Pentacam)

    Scheimpflug-based cameras (e.g., Pentacam) capture cross-sectional images of the anterior segment and can measure anterior chamber depth and angle parameters.

  6. When calibrating a fundus camera, the correct diopter compensation setting for a patient with −4.00 D myopia is:

    Answer: Set to −4.00 D on the camera's diopter dial

    The camera's diopter compensation dial should be set to match the patient's approximate refractive error so the retina is in focus.

  7. OCT angiography (OCTA) generates images of retinal vasculature WITHOUT dye by detecting:

    Answer: Decorrelation signal from moving red blood cells between repeated B-scans

    OCTA uses motion contrast algorithms that compare multiple repeated B-scans; moving erythrocytes produce a decorrelation signal that maps blood flow.