Certified Ophthalmic Medical Technologist (COMT) Practice Exam

What does "polymegethism" refer to in specular micrography?

1. Variation in corneal curvature

2. Variation in the size of endothelial cells

3. Variation in vision quality

4. Variation in eye pressure

The correct answer is: Variation in the size of endothelial cells

Polymegathism specifically refers to the variation in the size of endothelial cells in the cornea. In specular micrography, which is a technique used to examine the corneal endothelium, polymegathism is observed as a significant indicator of the health and functionality of the corneal endothelium. A healthy corneal endothelium tends to have a relatively uniform cell size; thus, an increase in polymegathism is often a sign of endothelial dysfunction or damage. This variation can be indicative of conditions such as Fuchs' endothelial dystrophy or other forms of corneal edema. By assessing the size variations of these cells, practitioners can gain insight into the overall health of the cornea and make informed decisions regarding treatment options. In contrast, variations in corneal curvature relate to different parameters and conditions affecting corneal shape, while variations in vision quality and eye pressure do not relate specifically to the characteristics being measured by specular micrography.