ISCHEMIC OPTIC NEUROPATHY
An optic nerve stroke causes atrophy of the whole head of the optic nerve, called papilla.
Ischemic Optic Neuropathy is a stroke of the optic nerve caused by the blockage of the short posterior ciliary arteries in charge of supplying blood to the head of the optic nerve, causing a significant and usually irreversible loss of visual field. This causes an afferent pupillary defect, i.e. the pupil does not respond well to light and in the eye fundus examination we find a papillary oedema.
There are two types of Ischemic Optic Neuropathy: Anterior and Posterior, with the Anterior being more frequent.
Anterior Optic Neuropathy can be associated to vascular risk factors such as hypertension, diabetes, and cholesterol or to an autoimmune disease such as temporal arteritis.
The latter receives the name of Arteritic Anterior Ischemic Optic Neuropathy. It is associated to jaw fatigue, rheumatism, periorbital pain and scalp hypersensitivity. It is treated with high doses of corticoids.
The diagnosis includes a blood test to measure specific inflammatory factors (C-Reactive protein – CRP – and erythrocyte sedimentation rate (ESR).
Non-Arteritic Anterior Ischemic Optic Neuropathy is much less severe than the aforementioned and its treatment consists on treating the underlying factors (hypertension, diabetes, and cholesterol)
Posterior Ischemic Optic Neuropathy is associated to diseases of the central nervous system, mainly demyelinating or viral infections
It is paramount to find the cause of these types of issues, ruling out neurological and cardiovascular problems as well as thrombophilia. Other triggering factors are sleep apnoea and nocturnal low blood pressure.
The visual loss reported by the patient at the practice is mainly due to the affectation of the patient’s visual field.