Certified Ophthalmic Medical Technologist (COMT) Practice Exam

Which two layers of the retina are primarily affected by glaucoma damage?

1. Nerve fiber and ganglion cell

2. Pigment epithelium and nerve fiber

3. Photoreceptor and outer nuclear

4. Inner limiting membrane and vascular layer

The correct answer is: Nerve fiber and ganglion cell

In cases of glaucoma, the primary damage occurs to the nerve fiber layer and the ganglion cell layer of the retina. Glaucoma is characterized by increased intraocular pressure, which can lead to the death of retinal ganglion cells and subsequent loss of nerve fibers. As these ganglion cells die, it results in a thinning of the nerve fiber layer, causing visual field loss which is a hallmark of the disease. The nerve fiber layer contains the axons of the ganglion cells that converge to form the optic nerve. When glaucoma progresses, this layer can show significant changes, and the loss of these nerve fibers correlates with the characteristic visual field defects found in glaucoma patients. In contrast to the other layers mentioned, the pigment epithelium, photoreceptor layer, outer nuclear layer, inner limiting membrane, and vascular layers are either less impacted in primary open-angle glaucoma or are not the primary areas affected by the disease process. Understanding the specific layers affected aids in both diagnosis and the monitoring of glaucoma progression.