Certified Ophthalmic Medical Technologist (COMT) Practice Exam

What does the GDx instrument image?

1. Corneal surface

2. Optic nerve and nerve fiber layer

3. Retina structure

4. Anterior chamber angle

The correct answer is: Optic nerve and nerve fiber layer

The GDx instrument is specifically designed to image the optic nerve and the nerve fiber layer, making it a valuable tool in the assessment of glaucoma. It utilizes scanning laser polarimetry to obtain detailed images that help in evaluating the thickness of the nerve fiber layer, which can indicate the presence of glaucomatous damage. By analyzing these images, clinicians can track changes in the optic nerve over time, allowing for early detection and monitoring of glaucoma progression. This focus on the optic nerve and nerve fiber layer is critical, as both are key areas affected by glaucoma. In contrast, the other options pertain to different anatomical structures not related to the primary function of the GDx instrument. The corneal surface, retina structure, and anterior chamber angle are assessed using different diagnostic tools and techniques, not GDx, which exclusively targets the nerve and its layer for accurate glaucoma assessment.