Posts Tagged vision rehabilitation.
Am J Phys Med Rehabil. 2016 Aug 22. [Epub ahead of print]
Visual impairments are common after traumatic brain injury (TBI) and negativelyaffect quality of life. We describe a 39-year-old woman with a severe TBI who wasevaluated by the inpatient optometry and vision rehabilitation service withfindings of complete right homonymous hemianopia and right cranial nerve IIIpalsy with 30-degree right exotropia (eye turn out) and complete right ptosis(eyelid will not open). The 30-degree exotropia advantageously generated 30degrees of right visual field expansion when the right ptosis was treated with amagnetic levator prosthesis, which restores eyelid opening. Once opened, thepatient used visual field expansion derived from a right exotropia to overcomefunctional impairments caused by right hemianopia. Field expansion improved thepatient’s wheelchair mobility and reaching tasks during inpatient therapy. Thisis the first report of visual field expansion by strabismus facilitated bycorrection of ptosis. Strabismus should be considered for its potential fieldexpansion benefits when homonymous visual deficits are present, beforeconsidering patching. A multidisciplinary vision rehabilitation team is wellsuited to make this determination.
Over the past decade, several factors have resulted in an increasing demand for optometrists trained in brain injury vision rehabilitation (BIVR). To start, there have been a significant number of brain-injured soldiers returning from Iraq and Afghanistan. Other factors include continually improving trauma survival rates due to medical advances, increased awareness of sports-related concussions and the increased incidence of cerebrovascular accidents (CVA) in the aging Baby Boomer population.1
Vision problems are common after brain injury, and recently published research supports the effectiveness of rehabilitative devices and therapy.2-9 As a result, it has become more important for rehabilitation facilities to seek and privilege optometrists trained in BIVR. In addition, ODs in general practice are increasingly likely to encounter patients with an acquired brain injury (ABI), such as a concussion, and asked to provide expert opinion concerning its impact on visual function.
As caring providers, we want to have the knowledge to offer our patients the newest and most effective treatments available for their visual dysfunction. I will discuss inpatient vs. outpatient delivery of care, diagnoses, assessment and treatment for the ABI patient. Currently there is no consensus on the best model for BIVR care, and there is no evidence to support one method over another.
The model described below is one that I developed for my inpatient clinics and was influenced by my early career in private-practice vision therapy, experience in an inner-city academic low vision rehab clinic, hospital-based experi ence with the medical model of rehabilitation and interaction with other optometrists working with the inpatient population.
[ARTICLE] Non-invasive electric current stimulation for restoration of vision after unilateral occipital stroke
Occipital stroke often leads to visual field loss, for which no effective treatment exists. Little is known about the potential of non-invasive electric current stimulation to ameliorate visual functions in patients suffering from unilateral occipital stroke. One reason is the traditional thinking that visual field loss after brain lesions is permanent. Since evidence is available documenting vision restoration by means of vision training or non-invasive electric current stimulation future studies should also consider investigating recovery processes after visual cortical strokes. Here, protocols of repetitive transorbital alternating current stimulation (rtACS) and transcranial direct current stimulation (tDCS) are presented and the European consortium for restoration of vision (REVIS) is introduced. Within the consortium different stimulation approaches will be applied to patients with unilateral occipital strokes resulting in homonymous hemianopic visual field defects. One goal is to evaluate effects of the stimulation on vision parameters, vision-related quality of life, and physiological parameters that allow conclude about the mechanisms of vision restoration as induced by electrical current stimulation. These include EEG-spectra and coherence measures, and visual evoked potentials. The design of stimulation protocols involves an appropriate sham-stimulation condition and sufficient follow-up periods to test whether the effects are stable.
This is the first application of non-invasive current stimulation for vision rehabilitation in stroke-related visual field deficits. Positive results of the trials could have far-reaching implications for clinical practice. The ability of non-invasive electrical current brain stimulation to modulate the activity of neuronal networks may have implications for stroke rehabilitation also in the visual domain.
What Is Hemianopia?
Hemianopia is a blindness or reduction in vision in one half of the visual field due to damage of the optic pathways in the brain. This damage can result from acquired brain injuries caused by stroke, tumor or trauma.
Stroke occurs when there is damage to a group of nerve cells in the brain often due to interrupted blood flow, caused by a blood clot or blood vessel leaking. Depending on the area of the brain that is damaged, a stroke can result in coma, paralysis of one side of the body, speech and vision problems, and dementia.
What Are the Different Types of Hemianopia?
The most common defect, right homonymous hemianopia, occurs in corresponding halves of the right field of vision. It can also occur in corresponding halves of the left field of vision (left homonymous hemianopia), in the upper half of the field (superior hemianopia), the lower half (inferior hemianopia), or both outer halves of the field (bitemporal hemianopia). In hemianopia, half of the field is blanked out on both eyes.
- Loss of half of the field of vision
- Decreased night vision
- Need for more light
Whoever may be at risk for stroke is also at risk for hemianopia. People with high blood pressure or those with an abnormal heart rhythm, which is associated with blood clots in the heart, may be at risk for stroke.
Age is also a risk factor, as the majority of people who experience stroke are over the age of 55.
What You Can Do to Reduce Risk
Reducing the risk of stroke will reduce the risk of hemianopia. For more information on how to reduce your stroke risk, visit the National Stroke Association.
Though there is no specific medical or surgical treatment for hemianopia, one’s effective use of vision may improve over time. In addition, there are optical devices that may be helpful in increasing the field of vision. Some examples include field-expanding prism lenses and magnifiers.
Following diagnosis of hemianopia, it is also important to receive a careful evaluation by a low vision specialist who can prescribe optical prism glasses and other devices, as well as recommend vision rehabilitation services. Vision rehabilitation specialists can teach people with hemianopia to maximize their existing sight by increasing lighting or using adaptive devices, for example.
NovaVision’s Vision Restoration Therapy, or VRT, is a restoration therapy specifically developed for patients who suffer from a visual field deficit resulting from a neurological trauma such as stroke or traumatic brain injury (TBI). VRT is a prescription therapy undertaken in the comfort of a patient’s own home, clinically supported by more than 15 years of research and 20 studies with FDA 510(k) clearance to be marketed in the US
While other rehabilitation modalities such as speech, physical and occupational therapy have been considered a standard of care for stroke and traumatic brain injury, NovaVision Vision Restoration Therapy addresses a previously unmet need for vision rehabilitation. Unlike other rehabilitation approaches that help patients compensate for their vision loss, VRT is developed to increase the sensitivity within the blind areas. Patients normally undergo VRT for six months, during which time they perform twice daily sessions six days per week, focusing and responding to light stimuli. Recent studies indicate that the mechanisms for recovery is based on neuroplasticity, the brain’s ability to adapt and form new connections or strengthen the pre-existing alternative pathways to overcome injury.