Visual field loss due to optic nerve cupping is primarily related to which condition?

Visual field loss due to optic nerve cupping is primarily associated with glaucoma. Glaucoma is a group of eye conditions that damage the optic nerve, often due to increased intraocular pressure. When the optic nerve is damaged, it can lead to cupping, where the optic disc becomes larger and more hollowed out. This cupping is a characteristic finding in patients with glaucoma and is directly related to the loss of peripheral vision, which can progress to tunnel vision and, if untreated, potentially result in total vision loss.

In contrast, conditions like tropia and phoria involve misalignments of the eyes and do not typically cause damage to the optic nerve or lead to cupping. Nystagmus is characterized by involuntary eye movements, which can affect vision but also does not involve optic nerve cupping or visual field loss in the same manner as glaucoma does. Therefore, glaucoma stands out as the condition primarily responsible for optic nerve cupping and associated visual field loss.