Which term describes changes such as progressive cupping observed in glaucoma?

The term that describes the changes like progressive cupping observed in glaucoma is referred to as the cup-to-disc ratio. This ratio is a key clinical measurement used in the assessment of glaucoma. It represents the relationship between the diameter of the optic cup (the depression in the optic nerve head) and the diameter of the optic disc (the area where the optic nerve fibers exit the eye).

In individuals with glaucoma, there is an increase in this ratio due to progressive loss of retinal ganglion cells, leading to a more pronounced cup as the nerve fibers are damaged. A higher cup-to-disc ratio indicates greater optic nerve damage and is a significant factor in diagnosing and monitoring the progression of glaucoma. Regular measurements of this ratio can help in determining the effectiveness of treatment and in making decisions regarding further interventions.

The other listed terms do not directly refer to this specific observation in glaucoma. Optic nerve edema refers to swelling of the optic nerve often due to other conditions, rather than to the changes seen in glaucoma. Choroidal thickness pertains to the layer of blood vessels beneath the retina, which is not specifically indicative of the changes occurring in glaucoma. Corneal refractive index relates to the eye's ability to bend light passing through it and does not reflect optic nerve changes