Certified Ophthalmic Technician (COT) Practice Test 2025 - Free COT Practice Questions and Study Guide

The primary test used to assess the thickness of the retina is optical coherence tomography (OCT). This imaging technique provides detailed cross-sectional images of the retina, allowing for precise measurements of its various layers, including the nerve fiber layer and the inner and outer retina. OCT is non-invasive and offers high-resolution images, which make it ideal for detecting conditions such as macular edema, retinal detachment, and other retinal diseases that may involve changes in retinal thickness.

Other imaging modalities, such as fluorescein angiography, are primarily used to evaluate blood flow and identify abnormalities in the retinal vasculature rather than measuring thickness. Pachymetry focuses on measuring the thickness of the cornea, not the retina, and ultrasonography is generally used for assessing more general structural aspects of the eye, such as potential tumors or foreign bodies, rather than the specific layering of the retina.

Therefore, optical coherence tomography stands out as the most appropriate choice for assessing retinal thickness effectively and accurately.