Some patients who have glaucomatous optic neuropathy and visual field loss have no elevation of IOP. Some might have IOPs that would consistently be considered normal. Normal tension glaucoma has been thought to be more frequent in Asian patients.
Optic disc cupping over time is characteristic of glaucoma. The visual field loss in glaucomatous optic neuropathy should conform to the areas of greatest optic disc cupping. An important finding in glaucomatous optic neuropathy is preservation of the normal color of the remaining neuroretinal rim. Other types of optic neuropathy, when present chronically, typically cause pallor of the remaining neuroretinal rim. Therefore, pallor of the neuroretinal rim suggests the need for neuroimaging studies in a patient who has an optic neuropathy.
Even though this patient's IOP was normal on the initial examination, she was found to have elevated IOP at a subsequent examination, helping to confirm the diagnosis and prompting initiation of treatment with a topical pressure-lowering agent.
Medscape Ophthalmology © 2014
Cite this: What's Happening to My Eyesight? - Medscape - Sep 11, 2014.