Posts Tagged Hemianopsia

[ARTICLE] Visual processing speed in hemianopia patients secondary to acquired brain injury: a new assessment methodology – Full Text

Abstract

Background

There is a clinical need to identify diagnostic parameters that objectively quantify and monitor the effective visual ability of patients with homonymous visual field defects (HVFDs). Visual processing speed (VPS) is an objective measure of visual ability. It is the reaction time (RT) needed to correctly search and/or reach for a visual stimulus. VPS depends on six main brain processing systems: auditory-cognitive, attentional, working memory, visuocognitive, visuomotor, and executive. We designed a new assessment methodology capable of activating these six systems and measuring RTs to determine the VPS of patients with HVFDs.

Methods

New software was designed for assessing subject visual stimulus search and reach times (S-RT and R-RT respectively), measured in seconds. Thirty-two different everyday visual stimuli were divided in four complexity groups that were presented along 8 radial visual field positions at three different eccentricities (10o, 20o, and 30o). Thus, for each HVFD and control subject, 96 S- and R-RT measures related to VPS were registered. Three additional variables were measured to gather objective data on the validity of the test: eye-hand coordination mistakes (ehcM), eye-hand coordination accuracy (ehcA), and degrees of head movement (dHM, measured by a head-tracker system). HVFD patients and healthy controls (30 each) matched by age and gender were included. Each subject was assessed in a single visit. VPS measurements for HFVD patients and control subjects were compared for the complete test, for each stimulus complexity group, and for each eccentricity.

Results

VPS was significantly slower (p < 0.0001) in the HVFD group for the complete test, each stimulus complexity group, and each eccentricity. For the complete test, the VPS of the HVFD patients was 73.0% slower than controls. They also had 335.6% more ehcMs, 41.3% worse ehcA, and 189.0% more dHMs than the controls.

Conclusions

Measurement of VPS by this new assessment methodology could be an effective tool for objectively quantifying the visual ability of HVFD patients. Future research should evaluate the effectiveness of this novel method for measuring the impact that any specific neurovisual rehabilitation program has for these patients.

Background

Vision is the dominant sensory function in humans because visual search and reach tasks are crucial to efficient performance of the main activities of daily life [12]. The term visual processing speed (VPS), an important variable of visual sensory function, is the amount of time needed to make a correct interaction with a visual stimulus [34]. The term correct interaction is the effective realization of a complete executive action of visual search and reach [5], e.g., visualizing a glass of water placed on a table and then grasping it by precise eye-hand coordination (EHC). Accordingly, the VPS variable defines the global reaction time (RT) that is composed of two additive RT sub-variables: search reaction time (S-RT) and reach reaction time (R-RT) [6,7,8]. Furthermore, VPS is mainly interdependent on intrinsic visual cognitive processing mechanisms, the complexity of the determined stimulus to be recognized (defined principally in terms of size, contrast, semantic content, and number of traces or interior angles [910]), the number of distractor stimuli surrounding it, and the distance from the point of fixation to the particular stimulus that the person is tasked to identify (eccentricity) [411,12,13]. Thus, VPS is a quantifiable parameter that objectively reflects a subject’s global visual ability.

Recent findings in the field of visual psychophysics show that having adequate VPS is necessary and dependent upon the proper functioning of six main brain-processing systems: auditory-cognitive, attentional, working-memory, visuocognitive, visuomotor, and executive [14,15,16,17,18]. Consequently, an acquired brain injury (ABI) that affects any of these cerebral processing systems could decrease the VPS.

ABI is one of the most important and disabling public health problems of our era due to the high incidence and prevalence [19]. Following an ABI, between 30 and 85% of patients will experience some type of visual dysfunction [2021], especially homonymous visual field defects (HVFDs) secondary to lesions involving the visual afferent pathways posterior to the chiasm [22]. Eye tracking technology has shown that HVFDs prevent patients from having the appropriate control of their oculomotor systems [23,24,25,26]. This is especially apparent in the saccadic system, because it is interdependent with the covert attention mechanisms associated with peripheral vision [2728]. Thus, patients with HVFDs tend to perform search tasks using unconscious compensatory head movements [252930] and employ longer total search times, more frequent fixations, and shorter saccades than normal controls [2331,32,33,34,35,36,37]. Therefore, these patients experience a significant reduction in their quality of life and functional independence. They complain that the time they have to invest in carrying out their daily activities is much greater than before suffering from HVFDs [3338,39,40]. In this regard, in recent years the scientific community has joined efforts to develop increasingly effective neurovisual rehabilitation training programs (NVRTPs) for these patients [41]. Different forms of NVRTPs have been developed, including compensatory NVRTP (C-NVRTP), restitution NVRTP (R-NVRTP), and substitution NVRTP (S-NVRTP) [41,42,43,44].[…]

 

via Visual processing speed in hemianopia patients secondary to acquired brain injury: a new assessment methodology | SpringerLink

Fig. 2

Fig. 2 Head Tracker System incorporated in the new software to measure the number of degrees of absolute head movements (dHM) performed by the study subjects, along the coordinate axes “X” and “Y”, while they performed the test. It consisted of specific software capable of detecting human faces (a), a fluorescent light (b), and a web camera (c) that registered the specific movement of a green point placed on a human mask positioned on the back of the subject’s head and neck (d.1 and d.2). The subject had to remain seated in front of the digital resistive-touch whiteboard at a distance of 40 cm (15.7 in.) and at 70 cm (27.5 in.) from the webcam

 

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[ARTICLE] Reversing Hemianopia by Multisensory Training Under Anesthesia – Full Text

Hemianopia is characterized by blindness in one half of the visual field and is a common consequence of stroke and unilateral injury to the visual cortex. There are few effective rehabilitative strategies that can relieve it. Using the cat as an animal model of hemianopia, we found that blindness induced by lesions targeting all contiguous areas of the visual cortex could be rapidly reversed by a non-invasive, multisensory (auditory-visual) exposure procedure even while animals were anesthetized. Surprisingly few trials were required to reinstate vision in the previously blind hemisphere. That rehabilitation was possible under anesthesia indicates that the visuomotor behaviors commonly believed to be essential are not required for this recovery, nor are factors such as attention, motivation, reward, or the various other cognitive features that are generally thought to facilitate neuro-rehabilitative therapies.

Introduction

Extensive damage to the visual cortex on one side of the brain produces blindness in the opposite hemifield (hemianopia) despite the sparing of other visual centers far from the site of the physical insult (Sand et al., 2013Goodwin, 2014). Of special note is the superior colliculus (SC), a midbrain structure that plays a major role in detecting, localizing, and orienting to visual targets. Its multisensory neurons allow it to use non-visual cues to facilitate this process (Stein and Meredith, 1993), and its location in the midbrain ensures that it is not directly damaged by a hemianopia-inducing cortical insult. Yet, as shown in the cat model of hemianopia, the loss of visual responses in the multisensory layers of the SC and the total absence of visual detection and orientation responses to contralateral visual stimuli following lesions of visual cortex reveal that it too is compromised, presumably via secondary excitotoxic injuries that may alter other input structures such as the basal ganglia (Jiang et al., 20092015). Interestingly, the dysfunction of SC appeared to be limited to its visual role. Its other sensory representations and sensorimotor roles remained intact: SC-mediated auditory and tactile detection and orientation responses were readily elicited (see also Sprague and Meikle, 1965).

Previously it was shown that hemianopia could be reversed using a non-invasive multisensory training paradigm (Jiang et al., 2015). The procedure consisted of presenting cross-modal combinations of spatiotemporally congruent auditory-visual cues in the blind hemifield of alert animals engaged in a sensory localization task. Because the animals were not deafened by the cortical lesion, they readily responded to the auditory-visual stimulus complex. After only a few weeks of daily multisensory training sessions, a striking change occurred: not only could the animals now detect and localize a visual stimulus throughout the previously blind hemifield, but they could also discriminate elementary visual patterns there. Visual responses that had been lost in the multisensory layers of the ipsilesional SC also returned, and cortico-SC circuits normally engaged in multisensory integration (i.e., projections from the anterior ectosylvian sulcus, AES) were found to be crucial for the recovery. The recovery could not be induced by training with visual or auditory cues alone. In an important series of studies in human patients, Làdavas and colleagues (Bolognini et al., 2005Leo et al., 2008Passamonti et al., 2009Dundon et al., 2015a,b) used a similar training paradigm and also met with success in evoking contralesional visual responses.

It is commonly believed that the success of this rehabilitative paradigm is a retraining of the visuomotor targeting behavior itself (see, review in Dundon et al., 2015a). In this case, the key factor would be the orienting action (initially elicited by the auditory stimulus) in the presence of the visual stimulus. Also, if true, it is reasonable to hypothesize that the effectiveness of this paradigm would be facilitated by other factors such as motivation, attention, arousal, and reinforcement, as these are commonly believed to enhance most neuro-rehabilitative therapies. An alternative explanation, however, is that the paradigm operates via the brain’s inherent mechanisms for multisensory plasticity, which operate independent of these factors and can be engaged under anesthesia (Yu et al., 2013). In this case, the requirement would only be repeated, reliable exposure to the visual-auditory stimulus complex in the blinded hemifield. The present study examined this possibility directly.

Materials and Methods

Adult mongrel cats (four male, three female) were obtained from a USDA-licensed commercial animal breeding facility (Liberty Labs, Waverly, NY, USA). The experimental procedures used were in compliance with the National Institutes of Health “Guide for the Care and Use of Laboratory Animals” (8th edition, NRC 2011) and approved by the Institutional Animal Care and Use Committee at Wake Forest School of Medicine. Each animal was first screened to ensure that it was tractable and responded to visual and auditory stimuli in both hemifields. All efforts were made to minimize the number of animals used.

Visual Detection and Orientation Testing

Visual orientation capabilities were quantitatively evaluated in a semicircular perimetry arena using previously described methods (see Jiang et al., 2015, see also Figure 1A). Animals were maintained at 80%–85% of body weight and obtained most of their daily food intake during, or immediately after, each behavioral session. Each animal was first trained to fixate directly ahead at a food reward held in forceps by one experimenter and protruded through a hole in the front wall of the apparatus 58 cm ahead at the 0° fixation point. Trial initiation was always contingent upon the animal establishing fixation. Once released by the animal handler (a second experimenter), the animal was required to move directly ahead to obtain the food reward. It was then trained to respond to the test stimulus (a white ping-pong ball at the end of a stick) presented at any 15° interval from 105° left to 105° right. This required little training as animals responded to the stimulus almost reflexively. Stimuli were presented manually and introduced suddenly from behind a black curtain while the animal was fixating. Additionally, on some trials, the ball remained hidden behind the opaque curtain and was tapped on the side of the apparatus to produce an auditory stimulus. If the animal oriented to and approached any test stimulus it was rewarded there, but could also move directly ahead to obtain a similar reward at the fixation point. The animal handler did not know the location of the upcoming test stimulus. This was determined by the experimenter holding the food reward, who also ensured that the trial did not begin if the animal had broken fixation. The verbal command “Go” triggered the release of the animal. “Catch trials” in which no stimulus was presented were interleaved with test trials at different locations to encourage the animal to minimize breaks in fixation, scanning movements, and “false” responses. Generally, in a given session, each of the 15° locations was tested at least 4–5 times. With few exceptions, the total number of trials/location was at least 100. The training criterion was an average of 95% correct responses. All animals reached criterion readily, had normal visual fields, and their weekly weight records revealed stable weight profiles.

Figure 1. The testing, training, and multisensory exposure paradigms. (A) Visual and auditory detection/localization capabilities were first assessed on both sides of space using a simple behavioral task. Cats were trained to fixate forward at 0° then orient to, and directly approach, a visual or auditory stimulus at any location in space. Visual stimuli were produced by lowering a ping pong ball below an obscuring curtain, and auditory stimuli were produced by tapping the ball against the apparatus wall while still obscured by the curtain. (B) Following surgery, a rehabilitation paradigm consisted of weekly sessions in which animals were exposed to cross-modal cues while anesthetized. As shown by the schematic at the lower left, the central LED (at 0°) of the display was briefly illuminated to signal the onset of the trial. It was followed by the combined LED-broadband noise burst at 45° in the contralesional hemifield. Traces illustrate the onset and duration of the stimuli. Panel (A) adapted from Jiang et al. (2015).

Continue —->  Frontiers | Reversing Hemianopia by Multisensory Training Under Anesthesia | Frontiers in Systems Neuroscience

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[VIDEO] Hemianopia conversation technique – YouTube

Left Homonymous hemianopia ways of meeting and talking to people

 

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[Abstract] Computer-Based Cognitive Rehabilitation in Patients with Visuospatial Neglect or Homonymous Hemianopia after Stroke

Abstract

Objectives: The purpose of this pilot study was to investigate the feasibility and effects of computer-based cognitive rehabilitation (CBCR) in patients with symptoms of visuospatial neglect or homonymous hemianopia in the subacute phase following stroke.

Method: A randomized, controlled, unblinded cross-over design was completed with early versus late CBCR including 7 patients in the early intervention group (EI) and 7 patients in the late intervention group (LI). EI received CBCR training immediately after inclusion (m = 19 days after stroke onset) for 3 weeks and LI waited for 3 weeks after inclusion before receiving CBCR training for 3 weeks (m = 44 days after stroke onset).

Results: CBCR improved visuospatial symptoms after stroke significantly when administered early in the subacute phase after stroke. The same significant effect was not found when CBCR was administered later in the rehabilitation. The difference in the development of the EI and LI groups during the first 3 weeks was not significant, which could be due to a lack of statistical power. CBCR did not impact mental well-being negatively in any of the groups. In the LI group, the anticipation of CBCR seemed to have a positive impact of mental well-being.

Conclusion: CBCR is feasible and has a positive effect on symptoms in patients with visuospatial symptoms in the subacute phase after stroke. The study was small and confirmation in larger samples with blinded outcome assessors is needed.

via Computer-Based Cognitive Rehabilitation in Patients with Visuospatial Neglect or Homonymous Hemianopia after Stroke – ScienceDirect

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[VIDEO] Hemianopia – Half blind – YouTube

This is an attempt to show people how I see the world since my brain injury 8 years ago. This is what I see when I’m going shopping… I hate going shopping… I rarely go full shopping….. My left side of vision is missing, it’s not really black, it’s just not there, but I can’t explain it… and what I have left, is what you see here… My camera caught it all perfectly, sun glare as well… So if I don’t recognise you in the street, it’s really because I can’t see your face. If I need to see your face, I look for the right side edge of your face and look above you… that helps me see more of your features. But to be honest, I’ve kind of got used to not seeing people’s faces. I look at the floor a lot so I can see people’s feet, so I can sort of work out where they are if they are too close to me. Gradually, over 8 years I have adapted to doing things, walking, etc on the right. I stop in mid walking sometimes because I saw a person in front of me, then they vanished to my left and I wasn’t sure how close to me they were and I didn’t want to bump into them…. I cope better in wider spaces. Narrow corridors look even more narrow. I discreetly use my hands to touch anything that might be too close, so that I know to move myself away. I still walk into things and get hurt. If I turn my head too quickly, then I go off balance and sometimes fall over. It is very frightening when you can’t see properly, but look normal to everyone else. I’m not too bad if I’m with someone else. I constantly rely on touch… Hence doing Papiér Maché instead of drawing or painting. Also, I still get lost and wonder where I am, even sometimes going past my own house… I haven’t read a book in years, and I used to like reading… I couldn’t work out why I couldn’t see the words properly, and they kept vanishing, and the bits that I could see were double vision – then I had prisms fitted in my glasses lenses, which helped with the double vision, but I still couldn’t work out why I couldn’t see properly. I was officially diagnosed in January 2017. The Neurologist said despite all that, I had made some very good ways of trying to cope… It still is a struggle, but I do my best.

via Hemianopia – Half blind – YouTube

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[VIDEO] SYMPTOMS OF HEMIANOPSIA – YouTube

 

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[BLOG POST] Management hemianopia

Hemianopia, partial loss of the field of vision, is a condition usually the result of a stroke although other neurological disorders such as tumours can be responsible.

From the Greek; hemi – half, an – without, opia – sight.

Damage to an individual’s brain in the area responsible for interpreting visual input is the most common cause;

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Normal field of vision

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Hemianopia

The thing about hemianopia is that often the person experiencing the condition is unaware. Imagine the entire right side of your world stops existing; your brain, just as with your physiological blind-spot very quickly recovers and compensates.

People who have experienced strokes will not uncommonly eat a meal and leave half the plate, not because they can’t see it (which they can’t), but because for that person there is no right or left side of the plate.

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We call this situation neglect. I guess that is apposite.

I first encountered this in Oliver Sack’s case histories. I can remember the story of a man waking-up in bed to find a strange object beside him; inert, disconnected – it was his own leg. (This might have been Alien Hand Syndrome, that is for another day.)

(For this reason, medical students, if you ever talk with someone who has experienced a major stroke, always make sure you are in their field of vision and not presenting as a disembodied voice.)

Once understanding this concept, I thought I would stretch the idea to include the way that certain branches of management operate.

It is all too easy for me to pick hospital management, but, what the heck.

Imagine you are running an organisation – it is perhaps doing OK, books balanced, care, treatment, production all at levels you anticipated at the start of the year; the plan is on plan. Beautiful; you can even go on holiday and chill-out.

If back home things go wrong; I don’t know, perhaps, the money that was thought to be in the bank is actually a deficit or, the equipment you have been using to undertake operations is in some way faulty, you have two options.

One, investigate, get as much information as possible, conclude and communicate.

The other, is to do the above, but pretend all is OK; assume that everything will be well – this, the ostrich strategy you might call it is more common within organisations than at first might seem logical; we have the 2007/8 Global Financial Crisis as a case study.

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Much analysis has happened since that time and is ongoing; in healthcare, our equivalent is the Mid Staffordshire Hospitals – is disaster the wrong word*? People running so fast on a treadmill that if they get off the uncertainty is more frightening than their high-speed collapse.

Good, clever, insightful people become blinded to what is obvious; hemianopia. It is there, it is clear to everyone else, but in the case of the afflicted it doesn’t exist.

Other words are lacuna, scotoma, absence.

Through careful therapy, a person can recover from hemianopia – utilising mirror-neurones, physical and psychological treatments, that which was lost can return.

How do we support those caught in management hemianopia to recover? Is there a treatment or a means of defence?

Be open, honest, vulnerable and candid.

Don’t hide behind false prophets or slogans.

Acknowledge that the world is never entirely knowable; accept dissonance. Ask for help.

And, if the humility isn’t there? If the situation is extreme and the walls falling-down?

What would you do?

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*Officially it was a ‘scandal’

via Management hemianopia – almondemotion

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[WEB SITE] Hemianopia: Types, causes, symptoms, diagnosis, and treatment

hemianopiaHemianopia, also referred to as hemianopsia, comes from a culmination of three different Greek words: “hemi” translates to “half,” “an” translates to “without,” and “opsia” translates to “vision.” Hence, it literally means “being without half of your vision.”

This is a condition where half of your visual field can either be completely blind or partially diminished as a result of head trauma, a tumor, or suffering a stroke.

People who suffer from migraine headaches may sometimes experience temporary hemianopia or other visual disturbances, but this typically subsides on its own after a migraine goes away.

Homonymous hemianopia occurs when you lose part of your visual field on the same side of both eyes. This happens frequently to stroke patients or people who’ve suffered traumatic brain injuries. Visual images that are captured on the left side of the brain are communicated to the right side and vice versa, which is why hemianopia typically affects the same side of each eye equally.

The opposing posterior sides of the brain correspond to the opposite eye, which means that if an injury occurs on the left side of the brain, the visual field defects occur in the right eye.

What are the types of hemianopia?

As an umbrella medical term, there are actually five types of hemianopia and two subcategories in total. In fact, the hemianopia type that a patient suffers from is typically correlated with the exact site of the visual field defect.

Homonymous hemianopia

Visual field is lost on the same side in both eyes, depending on which side of the brain is affected by a stroke or injury. The left optic nerve controls the right visual field and the right optic nerve controls the left visual field. The diminished vision is instrumental in helping doctors locate the exact area of the brain that’s been injured or where the stroke occurred.

Heteronymous hemianopia

Loss of vision occurs in different fields of the eyes. Heteronymous hemianopia is separated into two different categories:

Binasal hemianopia: Blindness or vision loss occurs in the field of vision that’s within the closest proximity to the nose. This is caused by lateral damage to the retinal nerve fibers that don’t cross in the optic chiasm. They’re also responsible for registering information and sending it to the temporal retina.

Bitemporal hemianopia: As the name suggests, bitemporal hemianopia is a loss of vision that happens on the side of the eyes that’s closest to the temple. Lesions and damage to the optic chiasm can cause bitemporal hemianopia. The optic chiasm is located near the pituitary gland where the nerves from the left and right eyeballs meet and cross over one another to reach the opposite side of the brain.

Quadrantanopia

Loss of vision occurs in one quadrant or portion of the visual field, and this usually depends on the part of the brain that’s damaged. The area that’s connected to the damaged portion of the brain will suffer either partial or complete hemianopia.

Superior hemianopia:Superior hemianopia is when loss of vision occurs in the upper visual field of either the left or right eye or both.

Inferior hemianopia:Inferior hemianopia is when loss of vision occurs in the lower visual field of either the left, right, or both eyes.

What causes hemianopia?

There are several different factors or injuries that can cause hemianopia including brain injuries, strokes that occur in certain parts of the brain, and physical head trauma.

As mentioned, while severe migraines can cause temporary hemianopia and adversely affect the patient’s vision, this symptom typically subsides on its own once the migraine pain is relieved.

However, there are more permanent and hazardous causes of permanent hemianopia.

Brain injuries

Damage to certain parts of the brain such as blunt force trauma due to an accident or sports injuries accumulated over an extended period of time can lead to hemianopia in the visual fields of the eyes. These injuries can incur the growth of lesions or contusions on the brain over long periods of time, which can cause hemianopia in old age or even earlier on in life depending on the severity and frequency of the injuries.

Brain tumors

As brain tumors begin to form and continue to grow over time, they can have the same effects as traumatic brain injuries. Eventually, the pressure and damage caused by the tumor can directly result in hemianopia in either one or both of the eyes.

Stroke

Strokes typically occur as a result of insufficient supply of oxygen reaching the brain. Oxygen is important because it promotes healthy and stable cranial functions. The blockages happen for a number of reasons, the most common one being the formation of blood clots. Depending on the severity of the stroke, it could be fatal for the person who endures it. While survival is certainly preferable, it also means enduring various physical and mental ailments, including hemianopia.

What are the symptoms of hemianopia?

Hemianopia has a variety of signs and symptoms that are associated with it, including the following:

  • Loss of peripheral vision on one or both sides of the face
  • Loss of visual awareness
  • Constantly bumping into people or objects on a regular basis
  • Failing to notice objects or people on the side of the face where the hemianopia damage has occurred
  • Inability to process entire sentences, phrases, or words when reading due to disturbed or interrupted visual patterns
  • Visual hallucinations, as in seeing things that aren’t necessarily there such as certain lighting effects

In addition to the physical indicators of hemianopia, there are also a few psychological, emotional, cognitive, and even social repercussions. Many patients who suffer from hemianopia can become increasingly frustrated or frightened as their condition worsens because it can make mobility and attending social events extremely difficult. As a result, this loss of field vision can also have a negative effect on a person’s ability to live independently and a lot of patients may become gradually reclusive because they fear the outside world and enduring potential injuries.

Mounting irritation, aggravation, and stress also accompany hemianopia because people who suffer from it constantly think that people are bumping into them or objects are appearing out of nowhere. This can make it virtually impossible to function normally in crowded places. Part of the problem is that a lot of people don’t even realize that they have hemianopia until they’re officially diagnosed with it.

How is hemianopia diagnosed?

In order to accurately diagnose hemianopia, your optometrist will most likely send you to a specialist who will then conduct a series of tests on your vision. They’ll start off by asking you a series of questions with the intent of gaining a thorough and clear understanding of the symptoms you’re experiencing. You’ll also undergo a series of visual tests using a machine called a Humphrey Field Analyzer.

This machine tests the depth of vision in each eye individually. It flashes lights in each possible point of your vision including the upper left, lower left, upper right, lower right, and the center. All you have to do is press a button to indicate when you see the light. If the machine detects that you’ve missed the light multiple times in the same areas, it’ll determine that there may be blank patches within your visual field and this is an indication that you may have hemianopia.

Following this assessment, if it’s determined that you do have hemianopia, your doctor may then order a series of MRI tests to establish the initial cause of this condition, whether it was a brain injury, stroke, or a tumor.

How is hemianopia treated?

It’s important to note that while hemianopia treatments can be highly effective and rehabilitative, there’s no actual cure for this condition and you will have to continuously undergo various relief methods that can only stand to improve the condition and make it more manageable.

That said, the following is a list of treatment options for hemianopia. It’s up to your doctor to determine which one would be the most suitable for you depending on the type and severity of the hemianopia you have. In some cases, it might even be appropriate and useful to incorporate a combination of these treatments. Again, your doctor will typically use their own expertise and discretion in such cases.

Visual restoration therapy

This is provided by NovaVision and uses computerized software to help improve patients’ vision in half-hour increments where the patient is instructed to focus their gazes on a specified point and must move their head whenever they see a flash of light or other stimuli in their field of vision. This information is recorded by the computer and the treatment is adjusted with each session and progress of the patient.

Audio-Visual stimulation training

This is a multi-sensory visual training approach to attempting to improve the visual fields of people who suffer from hemianopia and it’s especially effective for treating homonymous hemianopia. It stimulates both the auditory and visual senses in an attempt to get them to work harmoniously with one another and improve the patient’s quality of life despite having this condition.

Optical visual span expanders

These are specialized sunglasses that are formulated specifically for each individual patient and their level of hemianopia. The sunglasses have prisms embedded in their lenses that can help enhance the patient’s vision and expand their field of vision while wearing them.

Explorative saccade training

Also referred to as scanning therapy, this technique tests the speed and correlation with which both eyes move from one focal point to another. The optometrist will observe as the patient’s eyes jet from one vertical or horizontal focal point to another and examine whether the eyes separate or move in unison. People who suffer from hemianopia are taught to incorporate this visual technique in their everyday lives to help them naturally expand their field of vision in every direction.

How does hemianopia effect everyday life?

Hemianopia can have a detrimental effect on a person’s everyday life if left untreated. Especially as people get older, they tend to become more reclusive due to this condition because they feel like burdens to their loved ones and everyone around them. People with diminished eyesight may have a hard time moving around without bumping into people or objects and because their line of vision is diminished as well, they most likely will have to surrender their driving privileges as well. This can make them feel like an even greater burden on their family and friends if they need to be driven everywhere or require the special assistance of a loved one or caregiver.

Hemianopia will undoubtedly have a strong impact on your everyday life, but that doesn’t mean it has to hold you back from being able to resume your regular activities or from doing the things you enjoy. By learning proper management and adaptation techniques, you can learn to live with and even conquer symptoms associated with hemianopia. If you’ve recently suffered a stroke, brain injury, or tumor and are noticing a vast decline in your vision, express these concerns to your doctor immediately so that they can start taking steps to administer a helpful treatment plan.

Related: How to improve vision: 11 home remedies to improve eye health

Related Reading:

Blurred vision in one eye: Causes, symptoms, and home remedies

Ocular migraine (retinal migraine): Causes, symptoms, and treatment

Sources:

https://books.google.co.in/books?id=tdODr5fpxEAC&pg=PA992&lpg=PA992&dq=Heteronymous+Hemianopia&source=bl&ots=7eMadgAuZ5&sig=VfCOZ_8hCtqijgXOOGKrlICn8ao&hl=en&sa=X&ved=0ahUKEwjv5Nakvv_YAhVJrY8KHeXgAZEQ6AEIrAEwFw#v=onepage&q=Heteronymous%20Hemianopia&f=false
http://www.eyesearch.ucl.ac.uk/es/es_hemianopia.php
https://www.revolvy.com/main/index.php?s=Binasal%20hemianopsia

 

via Hemianopia: Types, causes, symptoms, diagnosis, and treatment

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[WEB SITE] Stroke Victims Look to Innovative Glasses to Improve Side Vision


CORONA, Calif.May 3, 2016 /PRNewswire/ — In addition to being the fourth leading cause of death in the United States, strokes can lead to any number of life-changing disabilities. One of the most common side effects of the estimated 800,000 strokes that occur each year in the country is a loss of side vision (hemianopsia) of up to one-half to the right or the left. With May being both “Stroke Prevention Month,” as well as “Healthy Vision Month,” there is a new focus on the challenges patients with stroke-related hemianopsia face, as well as the hope that advanced Side Vision Awareness Glasses (SVAG) can provide.

Logo – http://photos.prnewswire.com/prnh/20160502/362416LOGO

“When individuals experience hemianopsia much more than just their side vision is reduced,” says Richard Shuldiner, OD, founder of The International Academy of Low Vision Specialists (IALVS), “Their quality of life diminishes, too.”  So concerned about bumping into others or accidentally walking off a curb or into traffic, the condition can leave patients feeling insecure in unfamiliar surroundings. Some avoid going out altogether; others struggle to make it through the day. Though no treatment can actually restore the lost field of vision for these patients, Side Vision Awareness Glasses (SVAG) serve as optical field expansion devices that can increase patients’ viewing fields, improve their safety and enhance confidence.  So effective, patients with custom-made SVAG typically experience an increase of about 15 degrees in side vision awareness immediately upon putting them on. The use of SVAG may even allow some patients to resume driving.

Developed by IALVS member Dr. Errol Rummel, Director of the Neuro-optometric Rehabilitation Clinic at the Bacharach Institute for Rehabilitation in Pomona, NJ, SVAG represents an important advancement over other devices that came before them.  Crafted of lens materials known to minimize distortion, they are noticeably thinner. Also, there is no obvious line in front of the lens, no “thick button,” and no lens strip inserted through the front of the lens. The front of SVAG’s lenses is smooth and barely distinguishable from ordinary glasses.

More important than being better looking than previous devices designed to manage the condition, SVAG provides far-improved vision by offering the widest viewing area. Their vertical edge enables a person with hemianopsia to move their eyes just a few millimeters to access the SVAG area of the lens. Unlike devices that superimpose a narrow peripheral image over a person’s central vision, SVAG is easier for patients to use, as well as to learn to use. They’re also harder to break, because there is no glued seam splitting through the lens from front to back.

Patients with hemianopsia who are acutely aware of their side vision loss can often be trained to scan their eyes to compensate for their impairment, but for those who are unaware or inattentive to the condition, which doctors term “hemianopsia with neglect,” SVAG can go beyond increasing their field of vision—they can broaden their worlds.

In any case, a qualified low vision optometrist can help you determine whether Side Vision Awareness Glasses are right for you or a loved one.  All members of The International Academy of Low Vision Specialists are low vision optometrists with extensive training and experience in assisting patients suffering from stroke-related hemianopsia. To locate a member near you, simply visit their website: www.ialvs.com or call 1-888-778-2030.

For more information, contact:

Tracy LeRoux, The Link Agency, Inc.

(800) 291-0530

Email

SOURCE International Academy of Low Vision Specialists

Related Links

http://www.ialvs.com

 

via Stroke Victims Look to Innovative Glasses to Improve Side Vision

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[VIDEO] How to Biology & Anatomy: Optic pathways, visual fields and the lesions – YouTube

 

See the original video here: http://www.showme.com/sh/?h=xyvD3Gi Created by Dale Ledford, a college Biology, Human Anatomy, and Physiology instructor in Blountville, Tennessee.

via How to Biology & Anatomy: Optic pathways, visual fields and the lesions – YouTube

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