What is a Tunnel Vision?
Tunnel vision refers to a loss of one’s peripheral (side) vision. Tunnel vision is a symptom of an eye disease or neurological condition. Tunnel vision can be permanent or temporary. A temporary cause of tunnel vision may be visual aura with or without a presenting migraine. Permanent causes may include glaucoma, retinitis pigmentosa, retinal detachments, laser scars to treat diabetic retinopathy, or a stroke.
- Tunnel vision refers to loss of one’s peripheral vision.
- Damage to the brain or eyes can result in tunnel vision.
- Tunnel vision may be temporary or permanent.
Understanding Tunnel Vision
Tunnel vision is the loss of an individual’s peripheral vision leaving only their central area of vision. One will still be able to view things directly in front of them, just not on the sides. Common things that cause tunnel vision include the following.
Migraine auras are transient neurological symptoms, which usually last for 5 to 30 minutes before the onset of migraine pain. It is possible to have visual aura without a migraine headache. Visual aura is the most common aura (approximately 90%) with variable manifestations. Studies estimate 8% of the population has visual auras. A typical visual aura may begin as a flickering, unilateral, uncolored squiggly line. It may start in the center with gradual spread toward the periphery. The progression of visual aura across the visual field is slow, i.e., >4 minutes and gradually returns to normalcy within 20 minutes to an hour.
Glaucoma is neurodegeneration of the optic nerve and loss in retinal ganglion cells. Glaucoma is the leading cause of irreversible blindness. Glaucoma results in a slow, painless, loss of one’s peripheral vision and in the end stage, results in tunnel vision. Disease progression can be delayed with diagnosis and effective treatment to reduce the intraocular pressure of the eye.
Retinitis Pigmentosa (RP)
Retinitis Pigmentosa is an inherited disease which results in progressive peripheral vision loss. RP is estimated to affect 1 in every 4000 people in the United States, and approximately one in 5000 worldwide. RP the most common inherited disease of the retina. It typically presents in both eyes with the symptom of nyctalopia or loss of night vision, followed by narrowing of the visual field. Intraocular eye findings include the “classic triad” of bony spicule pigmentation, vascular narrowing, and the abnormal pallor of the optic disc.
Pan-Retinal Photocoagulation (PRP)
Pan retinal photocoagulation (PRP) is an effective treatment to decrease the risk of severe vision loss in patients with proliferative diabetic retinopathy. The procedure involves the creation of thermal burns in the peripheral retina leading to tissue coagulation to improve oxygenation to the retina. While effective, there are also concerns that PRP can result in choroidal effusions, exudative retinal detachments, macular edema, visual field deficits, and night vision defects. Depending on the size of the area treated, the procedure may also result in tunnel vision.
The eye is an extension of the brain; therefore, vision is often affected by a stroke. The location in the brain where the stroke occurs may result in a decrease in one’s peripheral vision. Tunnel vision is a result of a bilateral stroke affecting both halves of the visual field, with a macular (central) island of vision. Approximately 20% of stroke sufferers will have a permanent visual field deficit.
Risk Factors for Tunnel Vision
A history of visual aura or other eye conditions like glaucoma are risk factors for tunnel vision.
Tunnel Vision Symptoms
Tunnel vision is a symptom of a retinal or neurological condition, and is the loss of an individual’s peripheral vision. One will still be able to view things directly in front of them, just not on the sides.
Diagnosing Tunnel Vision
Temporary tunnel vision may not appear on testing, but permanent tunnel vision can be diagnosed from visual field testing. Visual field testing is also called perimetry and uses light levels to detect a patient’s sensitivity at different locations of the visual field. Neuroimaging may be ordered if a stroke is suspected.
Tunnel Vision Treatment
Treatment depends on the cause for the tunnel vision. It is important to diagnose a condition like glaucoma before it progresses to the point of tunnel vision. A comprehensive eye exam followed by additional testing such as a visual field and OCT are used to confirm diagnosis and determine if current treatment is effective.