Friday, March 12, 2010

Vision and Rehabilitation After Brain Trauma: Part 3

Eric Singman, M.D., Ph.D.
Vision Center of Excellence

March 12, 2010 - This is the third and final part of Dr. Eric Singman’s article on vision and rehabilitation after brain trauma.

The Role of the Neuro-Ophthalmologist in Vision Rehabilitation After Brain Injury

Vision rehabilitation after brain injury is usually initiated by the neuro-ophthalmologist. Efforts during the acute period usually involve simple but important measures such as replacing a patient's damaged spectacles, offering the patient an eye patch to alleviate diplopia, or protecting a lagophthalmic eye from exposure and drying out.

Long-term visual rehabilitation evaluations take into consideration the wealth of information often accompanying patients, such as the assessments from other ophthalmologists, physiatrists, neuropsychologists, neurologists, and neurosurgeons. After offering the patient a full eye examination and vision evaluation, the neuro-ophthalmologist can then best decide what ancillary testing and consultations might be needed. Some commonly employed testing devices include:

a. Automated Perimeter: This device helps to map a patient’s peripheral vision and evaluate for possible damage to the visual cortex and other parts of the visual pathways.

b. Visual Evoked Potential Analyzer: This device measures the speed and strength of the neuro-electrical signals passing along the optic nerve to determine whether the nerve was damaged in a way often too subtle to detect via other means.

c. Electroretinogram: This device measures the speed and power of neuro-electric signals created by the retina during the conversion of light energy in order to determine whether there was a loss of function that might be too subtle to detect otherwise.

d. Synoptophore: This device helps determine whether a patient can still use the two eyes as a team to form a single 3-dimensional image.

e. Notably there are many variations of these devices and each can provide helpful information to pinpoint and sometimes even confirm the presence of damage.

The Neuro-ophthalmologist will always evaluate a patient for abnormal eye movements and often refer the patient to orthoptists or behavioral optometrists, colleagues with particular training in eye-teaming disorders. He will also investigate whether a patient can be helped with low vision assistance devices such as magnifiers and glare-control measures. At times he will be required to discuss medical and surgical options for patients with uncontrollable diplopia or nystagmus. A referral to a blind-rehabilitation specialist will be required for those patients whose vision loss is too severe to rehabilitate or not amenable to the novel restorative surgeries currently available. The neuro-ophthalmologist must also ensure that he coordinates his rehabilitative plans with those of occupational-, physical- and vestibular-therapists.

For many patients, the neuro-ophthalmologist represents the last step in the rehabilitation plan and the first step in the care patients will need for the remainder of their lives. This includes maintaining vigilance for the appearance of systemic disorders that often result after brain injury and which can directly or indirectly threaten vision, such as depression, weight gain, sleep apnea, migraine, diabetes, hypertension, stroke, and heart attack. Some of the eye conditions that can stem from these medical problems include stroke in the blood vessels of the eye and optic nerve, glaucoma, bleeding in the eye, swelling of the optic nerve, loss of peripheral vision, diplopia, difficulty reading, and loss of visual clarity.

Patients suffering traumatic brain injury might unfortunately experience depression, which can lead to neglect of medical problems and delay in diagnosis of associated medical conditions, including visual problems. Brain trauma can also exacerbate or accelerate underlying cranial disease. It cannot be stressed enough that the team who helped the patient return to maximal medical improvement must also ensure that continuity of care for the patient is available. The patients and their families will rely on that continuity to help them adapt to and accept their new, post-brain injury life in which there are both unfamiliar challenges and new opportunities.

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