COT Ophthalmic Imaging and Photography 3

Question 1

Fundus autofluorescence (FAF) imaging relies on the natural fluorescence of which substance in the retinal pigment epithelium?

Accepted Answer

Lipofuscin

Answer

Lipofuscin, a byproduct of incomplete photoreceptor outer segment digestion, accumulates in the RPE and is the primary source of fundus autofluorescence.

Question 2

When performing corneal topography, the Placido disc system measures corneal curvature by analyzing:

Accepted Answer

Reflected concentric ring images from the corneal surface

Answer

Placido-based topographers project concentric rings onto the cornea and calculate curvature from the spacing and shape of their reflections.

Question 3

A cotton-wool spot on fundus photography corresponds pathologically to:

Accepted Answer

Focal nerve fiber layer infarction

Answer

Cotton-wool spots represent focal ischemic infarcts of the nerve fiber layer causing axoplasmic flow stasis and cytoid bodies.

Question 4

Which OCT scan pattern provides the most comprehensive macular thickness map for detecting early diabetic macular edema?

Accepted Answer

Macular cube (raster) scan

Answer

A macular cube (dense raster) scan samples the entire macular area with multiple parallel B-scans, providing a full thickness map.

Question 5

The cobalt blue filter on a slit lamp is used in conjunction with fluorescein dye primarily to evaluate:

Accepted Answer

Corneal epithelial defects

Answer

Cobalt blue light excites sodium fluorescein, which pools in corneal epithelial defects and fluoresces green, revealing the defect's extent.

COT - Certified Ophthalmic Technician Practice Test

COT - Certified Ophthalmic Technician Practice Test

COT Ophthalmic Imaging and Photography 3