What is Cortical Impairment?

Cortical impairment is a vision impairment caused by injury to the brain, while the eyes and optic nerves remain healthy and of normal appearance. Also known as cortical visual impairment or cortical blindness, cortical impairment can be caused by a number of different things and the available treatment options are variable. Diagnosis of this condition can be complicated, as people usually see ophthalmologists for eye problems, and a neurologist is better equipped to evaluate patients with this condition.

Although this condition is sometimes called cortical blindness, patients with cortical impairments are not actually blind. Symptoms of cortical impairment can include lack of depth perception, narrowing of the vision, changes in quality of vision over the course of the day, sensitivity to light, difficulty with low contrast vision, and other visual issues. During an eye examination, the patient's eyes and optic nerves will appear functionally normal. Historically, some patients with this condition were thought to be faking their impairments because nothing physically wrong with the eyes could be found.

If the patient's brain is evaluated, however, signs of damage to the brain will be apparent. A common cause of cortical impairment is ischemia, where bloodflow to the brain is restricted during strokes, near drownings, and asphyxiation. Traumatic brain injuries can also cause this condition, as can tumors and degenerative diseases involving the brain. A medical imaging study of the brain will show some areas of damage and the patient may have other impairments as well.

Treatment options for cortical impairment depend on the cause of the brain injury leading to the problem. If brain cells are dead, they cannot be resurrected, but relieving pressure caused by tumors and swelling in the brain might restore the patient's vision. Medications can control some degenerative diseases and patients can also wear glasses, eyepatches, and other devices to address their vision problems. For patients with extreme sensitivity to light, polarized lenses can be helpful.

A patient with cortical impairment can also benefit from low vision aids. This includes things like magnifying glasses for text, large print books, and high contrast labels for objects around the house. Depending on the level of impairment, activities like driving may be restricted, but the patient can generally enjoy a high activity level, including engaging in activities specifically designed for people with blindness or other vision impairments. Visually impaired people can be found on ski slopes, in the workplace, and in a wide variety of other settings with the assistance of adaptive technology and personal aides.