Neuro-Ophthalmology

Neuro-Ophthalmology is the specialty that is concerned with visual symptoms resulting from brain diseases. The visual symptoms can be divided into visual loss, or problems with eye movements. Visual loss may result from problems within the optic nerve or its connections to the visual portions of the brain. The eye is like a camera, and images are focused on the retina. The optic nerve is the cable that takes these images to the brain. There are several parts of the brain that are involved with precise control of eye movements. Difficulty within these regions often produces misalignment of the eyes with resultant double vision. Any of several processes may affect the optic nerve or its connections; including strokes, inflammation, multiple sclerosis or tumors.

Neuro-Ophthalmologists are physicians involved in the field of neuro-ophthalmology. Neuro-Ophthalmologists have completed medical school, and either a neurology or ophthalmology residency, followed by a neuro-ophthalmology fellowship.

Causes of Vision Loss

Visual loss may result from a problem within the eye or its connections to the brain. Blurred vision in one eye may be the result of a lens problem (glasses), cataract or other opacities blocking light’s entrance, a retinal problem, optic nerve disease or a lazy eye (amblyopia).

Causes of Double Vision (Diplopia)

Double vision may be divided into two general categories: monocular or binocular. Monocular double vision affects one eye at a time. If the unaffected eye is closed, the double vision persists. Monocular double vision results from eye disease, usually a lens problem or cataract changes. Binocular double vision is only present when both eyes are open and goes away when either eye is closed. Binocular double vision results from misalignment of the eyes. When the eyes are pointed in different directions, the brain perceives two separate images (one from each eye).

The eyes are kept aligned by the muscles that control eye movements, which in turn are controlled by three nerves from the brain. Misalignment (causing binocular double vision) is most commonly due to a problem with one of three areas: the nerves that connect to the eye muscles, the connection between the nerves and the eye muscles, or the eye muscles themselves. There are several things that can affect the nerves going to the eye muscles including strokes or tumors pressing on the nerves. The most common disease to affect the connection between the nerves and eye muscles is myasthenia gravis. There are several muscle diseases that may affect the eye muscles.

Diseases Treated by a Neuro-Ophthalmologist

Pseudotumor cerebri
Pseudotumor cerebri (PTC) is a disease primarily of young females. For reasons that are not understood, obesity appears to play a role in the disease. PTC results in elevated pressure inside the head (elevated intracranial pressure). This pressure typically produces headaches and swelling of the optic nerve heads. The swelling of the optic nerve heads may result in visual loss, and this is the most feared complication of the disease. The disease is diagnosed by excluding other causes of elevated pressure within the head through imaging (CAT/CT scan or magnetic resonance imaging) and lumbar puncture (spinal tap). Treatment begins with weight loss when appropriate, and may also include diuretics or surgery if medical means fail.

Optic neuritis
Optic neuritis refers to inflammation of the optic nerve. Optic neuritis typically produces blurred vision in one eye with pain or discomfort around the eye. The visual blur progresses over the first week, then stabilizes for several weeks before spontaneous improvement in most cases. Most patients regain vision of 20/40 (within three lines of 20/20 vision) by six months. The exam can help localize the blur to the optic nerve. Optic neuritis may occur without other disease, or can be associated with systemic diseases, such as multiple sclerosis (MS). Evaluation often includes an MRI scan to rule out other causes of optic nerve dysfunction, and to look for other evidence of MS. Treatment may include steroids (intravenous Solu-Medrol followed by oral prednisone), which increases the rate of recovery of vision.

Source: https://neurology.msu.edu/patient-care/neuro-ophthamology