Primary Open Angle Glaucoma
- Optic neuropathy associated with acquired excavation of the optic disc
- Elevated intraocular pressure may be present and may contribute to optic nerve damage
- Treated by reducing intraocular pressure with medication or surgery
- Slowly progressive nerve fiber bundle visual field loss—usually binocular but may be asymmetric
- Excavation of the optic discs—usually binocular but may be asymmetric
- Excavation first extends vertically, beginning inferiorly
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Tip: marked optic disc excavation always precedes visual field loss
- Visual acuity is normal until the optic disc is fully excavated (“cupped out”)
- Diagnose primary open angle glaucoma if visual field loss can be explained by optic disc excavation
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Trap: beware of imitators of glaucomatous excavation
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Tip: compressive, atrophic ischemic optic neuropathy, and even nutritional-deficiency, toxic, and hereditary optic neuropathies may display excavation of the optic disc if the patient had large physiologic cups to begin with
- Medical and surgical measures that lower intraocular pressure may attenuate or halt progression of visual field defects and optic disc excavation, but…
- Visual field defects may worsen despite effective lowering of intraocular pressure because other factors contribute to disease progression