Even though 45% of all medications prescribed in the UK are for older people, it is postulated that up to 50% of older people are non-compliant with their medication (SCIE, 2005).

The prescription of various medicines is central to medical care and the overall drug costs account to about 10 percent of NHS expenditures. Surveys carried out in literature enlighten us with the fact that approximately 30% to 50% of patients’ do not use of take their medications as recommended by their prescriber. (1). Statistics show that in 2007- 2008, the NHS in England spent £8.1 billion on drugs & if as many as 50% of the patients don’t take their medications as recommended, this could mean that £4 billion worth of medicines were incorrectly used (2) . Furthermore the additional cost of unused or unwanted medicines within NHS totals up to £100 million each year.

On top of that the estimated drug cost of unused or unwanted medicines in the NHS is around £100 million annually (3).

A Cochrane review “Interventions for enhancing medication adherence” concluded that improving medicines taking may have a far greater impact on clinical outcomes than an improvement in treatments (4). Therefore if the prescription is inappropriate in the first place it not only translates as a loss to patient but also involves the healthcare system and the society. The costs included here are both personal and economic.

Concepts of Adherence and terminology

There are three major terms which are commonly used in the literature to describe medication-taking behaviours i.e Compliance, Adherence and Concordance (5). According to Pound (6) initially, the term compliance was used to illustrate the medication taking behaviour, which was then replaced by the term concordance. The term compliance came into disfavour because it suggested that a person is passively following a doctor’s orders, rather than actively collaborating in the treatment process (3) Whereas concordance refers to the “anticipated outcome of the consultation between doctors and patients about medicine taking” It is viewed as successful prescribing and medication taking based on the partnership with the patient (6). However the most current, fashionable and accepted terminology is adherence, which is defined by McElnay (7) , as ” the extent to which a person’s behaviour (in) in terms of taking medicines, following diets or executing lifestyle changes, coincides with advice given by health care professionals “Adherence shifts the balance between professional and patient about the prescribers recommendations.

Pound (6) states that the above mentioned three terminologies tend to be used interchangeably but are incorrectly applied. Adherence can be viewed as the central aim, concordance is the process used to apply the central aim & compliance is the outcome of the process.

The benefits of medication might be restricted thereby causing a further deterioration in health as a consequence of non-adherence. . On top of this the economic costs do not only translate to wasted medicines only but also include the knock on costs which arise from increased demands for healthcare if (on the whole) health deteriorates. It is hence due to this reason that non-adherence is a major issue and should not only be seen as the patients dilemma. A fundamental drawback is represented in the provision of the healthcare, which is often due to a failure in completely agreeing with the prescription in the first place or to recognise the appropriate support that the patients might require later on during the treatment. Hence addressing non-adherence is by no means about getting patients to take additional medicines. Therefore tackling the issue of non-adherence involves the initial understanding of patient’s opinion on the medicine and then the various reasons to as why they are/might be reluctant or unable to use them.

Causes of non-adherence

There are many causes of non-adherence however they fall into two main overlapping categories i.e intentional and unintentional. Both types relate to the lack of an established pattern of medication taking which led to the incidental omission of medicines and may be experienced concurrently (8).

Purposeful or intentional non-adherence occurs when a patient makes a specific decision not to take the prescribed medication. The anticipation of drug-related side effects and general dislike of taking medicines are common causes of intentional non-adherence (9). While accidental or unintentional non-adherence occurs as a result of forgetting or misunderstanding instructions about the drug schedule .Unintentional non-adherence is proposed to be range from a random departure to medication omissions from a prescribed treatment regimen (10). Hence the main features of unintentional non-adherence focuses on altering medication contingent on self assessment or perceptions of mental health, stress or anxiety, forgetting to take medicines or simply altering the doses of medicines to fit in with daily chores.

A research carried out by Svensson (10) & Kippen (11) showed that older people adherent with their medication often link the administration of medication to specific lifestyle events, location, time, and patterns of daily activities. Below table 1.3.1 shows the common perceptions and characteristics of adherent and non adherent medication taking behaviors.

Table 1: Shows common perceptions and characteristics of adherent and non adherent medication taking behaviours.

Perceptions related to medication taking behavior

Intentional Non-adherence

Unintentional Non-adherence

Feeling unnatural taking medicines

Fears of prescribing errors/addiction

Life style change/ Disruption to daily routine

Adverse effects of medicines

Lack of faith in the prescriber

Drug related memory loss/ Forgetfulness

Long term risks of medicines

Failure to accept diagnosis

Altering dosing regimen

Past experience of medicines

Dislike of taking medicines

Being asymptomatic

Lack of comprehension of the need to take medicines.

Testing medicines against symptoms

Period of illness

Vulnerable group of people

Of all the age groups, medication taking behaviour in older people is of the highest concern. This is due to multiple reasons as described by Huges (12). Firstly, older people are highly likely to suffer from multiple diseases. Secondly, older people frequently administer three or more medicines concurrently to manage these conditions and third as a result of poly pharmacy, they are increasingly likely to mismanage their medicines (13). Furthermore, research shows the following as different lay beliefs by older people on medicine taking

The need to reduce the symptoms of hypertension, to feel physically better (14).

Fear of complications and desire to control blood pressure (10).

Positive confidence in the prescriber (15).

Apart from the elderly, another age group, where non- adherence is becoming a significant problem is in the pediatric population. In one of the studies carried out by Bush (16) it has been shown that one-third of the children in grades 3 to 7 reported they had used one or more prescription or non prescription medications in a 48 hour period. Adherence plans for children often require innovative approaches to encourage active participation in caring for their own health and how to use their medications appropriately.

Consequences of medication non-adherence

No matter how much critical the conditions are a patient might stick to his medication regimen, thus reflecting a loss of the health care system with increased use of medical resources, such as GP visits, unnecessary additional treatments, emergency department visits and hospital admissions.

One of the recent research shows that about 3-4% of UK hospital admissions are as a result of avoidable medicine related illness (17) & between 11 and 30 % of these admissions result from patients who don’t use their medicines as recommended by their prescriber (3). In a similar manner, in 2006-2007, figures show that that the NHS expenditures on hospital admissions (excluding critical care costs) was approximately about £ 16.4 billion (18). And the estimated costs of admissions, within the same year i.e. 2006 – 2007, resulting from patients not taking their medicines as recommended was found to be between £36 and £196 million respectively (18). Hence a reduction in these admissions and associated costs would be expected as the overall medicines adherence increases.

Factors affecting medication adherence

In accordance to WHO some of the main common factors reported to have a significant effect on adherence include: poverty, low level of education, illiteracy, poor socioeconomic status, unemployment, unstable living conditions, lack of effective social support networks, long distance from treatment centre, high cost of medication, changing environmental situations, high cost of transport, family related issues and culture & lay beliefs about illness and treatment.

In accordance to WHO the common belief of patients being the sole responsible for taking their treatment is misleading and most often reflects a misunderstanding of how other factors affect people’s behaviour and the capacity to adhere to their treatment.

Adherence, in short, is a multidimensional phenomenon which is determined by the interplay of five different sets of factors, each of which are termed as “dimension” by WHO (5) . Each of these dimensions are listed as under and shall be discussed in detail

Social/ economic factors

Provider-patient/ health care system factors

Condition related factors

Therapy-related factors

Patient related factors

Social and economic dimension

It includes limited access to health care facilities, medication costs, low health literacy, limited English language proficiency, unstable living conditions (homelessness), lack of family/social support network, and cultural beliefs about illness and treatment. Among these factors few shall be discussed in detail as under

English language proficiency

Both low health literacy and limited English language proficiency are barriers to adherence that deserve special consideration. Health literacy can be defined as the ability to read, understand and act on health information so that appropriate health decisions can be made.

The risk of unsafe use of prescription medicine, is high among people with low health literacy and limited proficiency in English language due to the complex nature of the printed information that is available and because these people often do not receive adequate verbal communication or sufficient time from health care providers.

Older adults with low health literacy may have trouble reading health information materials, understanding basic medical instructions, following prevention recommendations and adhering to medication regimens.

Social factors

Medication adherence is positively associated with social support and the availability of help from family and friends. Better outcome to treatment is observed in people who have social support from their friends/family (who assist them with their medication regimens)

Cultural beliefs and attitudes

Adherence to therapy, may overall be affected as a consequence of different attitudes which the patient may have towards health and medicine. Addressing these issues by the health care professionals is of prime importance so that the patients can get the most out of their medicines without compromising their health

In case of adults, different components of health and healing cannot be explained by no one list. Therefore each individual must be considered on individual basis. Two major key components are requisite i.e asking non-judgmental questions & listening, when it comes down to understanding the process of gaining an insight into patients beliefs (regarding health and healing)

Patients belonging from various ethnic minorities bring along their practices in the health care system. This sometimes puts the health care professionals at test, who have been professionally trained in the light of western philosophy and medicine. Although groups of people may have beliefs or practices in common, yet that doesn’t mean that they all can be classified under the same category. Within groups , the major differentiating factors include health status, educational level, sexual orientation etc (5).

Respect

Taking care of elder patients who belong from such backgrounds where they receive a great amount of respect (e.g. British Asian community ) should involve the element of respect combined with kindness. If they are approached with an attitude that consists even a tiny fraction of scolding or telling off, they might show resentment towards the adherence of medicine even though it may put their lives at risk. Therefore to put such patients at relieve it is of prime importance to show respect towards them .

Traditional therapies and cause of illness

Literature shows that two components such as religion and spirituality can play a vital role in the overall understanding of illness in its broadest sense among older people (19). The will of God for an improper behaviour, exposure to cold wind, natural causes etc are all different factors which older patients believe are major culprits for causing illness (20). This consequently leads them in such a situation where they end up giving God a chance to heal them or alternatively they seek help from a folk healer, try home remedies or pray for the treatment of their illness. An excellent example of this can be viewed within the Chinese culture where health may be seen as finding norm between ying & yang, which is much more like hot and cold (21). Now patients who follow Chinese health belief may try such approaches which targets at restoring the balance between ying and yang (using different varieties of food and herbs). Likewise, some Asian ethnic groups rely solely on traditional remedies for the treatment of long term conditions (21). At this stage it is also important to mention that the patient may not be cooperative if he believes that the health care provider may disapprove information surrounding the use of non-traditional remedies. This may ultimately lead to different interactions with the prescribed medications.

Medication

For some patients the preference lies in the dosage form or the size or colour of the medication. For example some cultures in Latin America view injections as more potent in comparison to oral medications. Likewise it is believed that Western medications are too strong by Chinese older patients & hence therefore they might choose to not take the full dose of medicine (22).

Health care system dimensions

It includes different factors such as provider-patient relationship, provider communication skills, patient information materials written at too high literacy level, restricted formularies (changing medications covered on formularies), poor access or missed appointments, long waiting time and lack of continuity of care (23).

The quality of the HCP-patient relationship is one of the most important health care system-related factors impacting adherence. Adherence to medicines can be increased as a result of good relationship between the patient and the HCP (which features the element of reinforcement and encouragement from the HCP), however there are many factors which have negative effect (24). These include lack of training and knowledge for health care providers on managing chronic diseases, lack of incentives and feedback on performance, poor medication distribution systems, short consultations, overworked health care providers, weak capacity of the system to educate patients and provide follow up, lack of knowledge on adherence and of effective interventions for improving it.

Condition related dimensions

It includes Psychotic disorders, severity of symptoms, chronic conditions, depression, lack of symptoms, mental retardation (25). Among these factors few shall be discussed in detail as under

Chronic conditions and lack of symptoms

Information within literature supports the fact that adherence to such treatment options (often declines as the time progresses) where medications have to be taken on an unlimited basis for the management of a chronic ailment. Example of two perfect clinical conditions which would fit into this profile include high BP and osteoporosis (26) , in which the symptoms are totally invisible to the patient. Furthermore, in the absence of symptoms these ailments lack the cues which would motivate the patient to adhere towards his treatment regimen.

Depression

A study carried out by Krueger (28) showed significantly lower rates of medication adherence among people with chronic illnesses and who are depressed. It is therefore crucial for the HCPs to be aware of the devastating impact, depression has on adherence & consequently on regular basis should assess older patients who are sad all the time or who report symptoms of sleeping disturbances to eliminate the possibility of clinical depression. The slow onset of the pharmacological actions posed by different classes of antidepressants is classified as one of the major factor that contributes towards decreased adherence among elder patients. Adding on to that if the patient begins to experience the side effects (before even the symptoms are relieved), might consequence discontinuation of the therapy at a very early stage. In a similar fashion, a research conducted by Kemyttenaere (29) shows that once the patients (suffering from depression) start feeling bette,r they might stop the antidepressant therapy midway.

Psychotic disorders

A patients experience with unpleasant side effects is mainly one of the key causes which drives them from continuing their antipsychotic therapy. Literature shows that interventions which focus mainly on the persons attitude and beliefs about medications 9rather than on the knowledge) helps improve adherence. The addition of two key ingredients i.e Behavioral techniques & motivational interviewing within compliance therapies, have proven to be very effective in improving medicines adherence among patients who suffer from psychotic disorders (31).

Therapy related factors/dimensions

It can be sub-divided into other different factors such as duration of therapy, lack of immediate benefit of therapy, frequent changes in medication regimen, actual or perceived unpleasant side effects, medications with social stigma attached to use, treatment requires mastery of certain techniques, complexity of medication regimen and treatment interferes with lifestyle or requires significant behavioural changes.

Research by Tabor (32) & Krueger (27) showed that decreased adherence is associated with medications with a social stigma attached to its use and with medications which require following complex regimen ( e.g. duration of therapy, number of daily doses required, or therapies that interfere with a person’s lifestyle.

Adherence can also be affected by other factors e.g. if administration of a medication requires the mastery of specific techniques like injections (32). In a similar fashion, when medications such as antidepressants are slow to produce effects, the patients/older person may believe that the medication is not working and might stop taking it. Likewise the side effects of a medication too can lower adherence if the patients start believing that they cannot manage or control them (25).

Patient related factors/dimensions

They can be sub-divided into two major factors i.e psychological/behavioral factors and physical factors.

Psychological factors include fear of dependence or possible adverse effects, knowledge about disease, motivation, perceived risk to disease & benefit of treatment, understanding reason of medication need, confidence in ability to follow treatment, feeling stigmatized by the disease, frustration with health care providers , psychosocial stress, expectations towards treatment and substance (alcohol) abuse.

Physical factors include issues like swallowing problems, hearing, visual & cognitive impairments and impaired dexterity or mobility.

Few of these physical and psychological factors can be discussed in detail as under:

Psychological factors that influence adherence

The WHO proposes a foundation model for medication adherence which is based on three major factors i.e. motivation, information and behavioural change. Behavioural change has been found to be influenced effectively by making interventions based on this model (33).

In accordance to WHO, adherence and non-adherence are different behaviours. In order to change behaviour, information is a prerequisite, but in itself it is insufficient to achieve this change. Hence at this stage behavioural and motivational skills are critical determinants. Motivation and information work largely through the behavioural skills to produce an impact on the behaviour. However, when the behavioural skills are uncomplicated or are familiar, the two aspects i.e motivation and information can produce a direct effect on the behaviour (33).

Physical Factors that influence adherence

The risk for non-adherence among older patients is increased due to physical and cognitive limitations.

Visual Impairment

Decreased ability to perform activities of daily living and an increased risk for depression is associated with vision impairment (34), (35). Furthermore there are many other medication safety issues associated with vision loss. A person’s ability to read patient information leaflets, prescription labels, determine the colour and markings distinguishing a medication is affected by low vision and blindness. Therefore consequently people who cannot read prescription labels or distinguish among different medications have to rely on their memory or depend on someone else for help and hence may not be able to take their medications correctly.

Hearing Impairment

Hearing loss is directly related with age. The natural aging process not only affects the ability to detect sounds at lower levels but also the capability to understand speech at a normal conversation level (36). This condition does gets worse with age and is progressive. It is therefore important to not assume when a deaf person nods his head in acknowledgement that he/she has understood, as he/she might be relying on a family member or a companion to explain later (36).

Impaired Mobility

Older patients with poor mobility may have difficulty in self administration of medicines or in obtaining medicines from the pharmacy (37).

Cognitive Impairment

Poor medication adherence is associated with Impaired cognition (25). Elderly patients with memory problems and cognitive impairment may have difficulty in understanding when to take, how to take or how much to take their medications.

Others factors also include as swallowing difficulties and impaired dexterity.

PREDICTORS OF medication non-adherence

Predictors of medication non-adherence can be a useful tool in the improvement of medicine adherence among older adults. Few of the non-adherence warning signs (38) include failure to fill in a new prescription, failure to fill in prescription for choric medication or failure to obtain refills as often as expected for medications taken on chronic basis.

Below are some of the more common predictors of medicines non-adherence (38):

Forgetfulness

Lower cognitive function or cognitive impairment.

Lack of insight into illness

Lack of belief in benefit of treatment.

Belief that medications are not important or are harmful.

Complexity of medication regimen

Tied of taking medications.

Inconvenience of medication regimen.

Side effects or fear of medication side effects.

Missed Appointments.

Substance Abuse

Limited English language proficiency.

Role of NICE (National Institute of Clinical Excellence):

The issue of non-adherence to medicine is a very important issue in its own essence. After assessing and understanding the impact of non adherence on the NHS the NICE (National Institute of Clinical Excellence ) came into action and published a guidance in January 2009 (Medicines Adherence: Involving patients in decisions about prescribed medicines and supporting adherence) to tackle and address this core issue (of non adherence). Before moving further it would be essential here to describe the role of NICE in terms of its function.

NICE was established as a special health authority on 1st April, 1999 & is an independent organisation that provides national guidance on promotion of good health and prevention and treatment of ill health in England and Wales (39). The institute’s main purpose is to offer NHS health care professional advice on how to provide patients with the maximum attainable standards of care and to decrease the variation in the quality of care . Furthermore, NICE is not part of the European Medicines Evaluation Agency (which assess the efficacy and safety of drugs), only licensed drugs on the basis of their added value relative to existing practice in the NHS are assessed by NICE (40). It has four programmes that produce guidance which are mentioned as under (39):

Public health guidance

Clinical Guidelines

Interventional procedures

Health technology appraisals ( for surgical interventions, pharmaceuticals, medical devices, etc)

Most programmes take into account both the elements of cost-effectiveness (how well an intervention works relative to its cost) and effectiveness (how well an intervention works)

NICE has an annual budget of 33 million pounds annually with over 250 full-time staff members working at offices based in London & Manchester. The processes NICE uses in the development of its guidance are highly consultative, evidence based and transparent. It also involves all relevant stakeholders, including policy makers, health professional managers, specialist, academics, representatives of health care industries, general public and patients (39).

The guidance that NICE produced to address the issue of medicine adherence was CG76 Medicines Adherence: Involving patients in decisions about prescribed medicines and supporting adherence.

This guideline was produced taking into account the patients views as to what they perceive as barriers to effective medicines adherence and thus encourages healthcare professionals to have a discussion with patients about their prescribed treatment especially for long term conditions. In addition to this the guidelines also open a pathway for dialogue and negotiation between the patient and the health care professional regarding their medication. A quick summary of the guidelines is as mentioned below

Summary of the NICE guidelines

Bullet-points below quote from summarise recommendations from the CG76 guidelines (41). The key recommendations from NICE guidelines are as under

Table 1: Shows the key recommendations from NICE CG76 guidelines.

Involving Patients:

Improve communication with patients

Increase patient involvement in the decision making process about their medicines.

Understand the patient’s perspective on their condition and possible treatments.

Provide information about their condition and possible treatments.

Supporting Adherence:

Assess adherence levels

Identify adherence issues

Address adherence issues

Review medication and its effective use

Improve communication between health care professionals in the care pathway.

From www.nice.org.uk/pdf/CG76fullguidelines.pdp

Significance of the Study

Community Pharmacists are the health care professionals which are most readily accessible to the general public and therefore continue to be the first line of Healthcare. They are experts on medicines and represent an important link in the chain of the health care professional team. Thus the main objective of this research project will be to provide a new insight as to what the community pharmacists reflect/perceive about these NICE CG76 guidelines. Hence their views and opinions will be assessed and analysed with regards to these NICE recommendations (as this would help in the implementation process). Any differences in the views of the pharmacists or any disagreement on the effectiveness of the NICE guidelines would mean that further investigation could be required to improve or update these recommendations.

Hypothesis:

H0 = There will be no statistically significant relationship between the years of experience of the pharmacists and the awareness of NICE CG76 guidelines.

H1 = There will be a statistically significant relationship between the years of experience of the pharmacists and the awareness of NICE CG76 guidelines.

H0 = Majority of the community pharmacists will not agree (on to a large extent) that CG76 recommendations have been effective in the improvement of medicines adherence among their patients.

H1 = Majority of the community pharmacists will agree (on to a large extent) that CG76 recommendations have been effective in the improvement of medicines adherence among their patients.

ARTICLE






.

The management of traumatic brain injury-induced visual midline shift syndrome and post trauma vision syndrome through the use of yoked prism and binasal occlusion.

The majority of individuals who have suffered a traumatic brain injury experience some level of physiological, visual and/or behavioural change that is associated with the injury. The two most common findings are post trauma vision syndrome and visual midline shift syndrome(8).

Post trauma vision syndrome was first described by Padula in 1994 who noted that the symptoms associated with the syndrome varied from diplopia and vertigo to difficulties reading and memory loss(6,7). He discovered that certain presenting signs were a common denominator amongst affected individuals, including a large exophoria or exotropia, reduced convergence and poor eye tracking. Padula also described visual midline shift syndrome in 1994 as “an unusual phenomenon that often occurs following a neurological event, that the ambient visual process changes its orientation to concept of midline.”(6)

Many visual disfunctions that are diagnosed after a traumatic brain injury frequently share a direct link to a problem within the ambient system’s capacity to process and organise spatial information. However, various studies have now demonstrated how yoked prisms are capable of shifting the concept of the visual midline in affected individuals, allowing them to regain their posture by realigning their weight to the affected side(2,2,7). Furthermore, binasal occlusion has been shown to provide the brain with an opportunity to process information in an alternate way by altering the visual input. This alteration has been shown to relieve visual symptoms as well as improve visual function for post-traumatic brain injury patients as demonstrated in this case report(3).

Visual complications as a result of a traumatic brain injury are often misdiagnosed and therefore mismanaged due to normal findings on neuroimaging and of the ocular structures. As such, affected individuals are often incorrectly diagnosed as having isolated binocular vision issues, including exotropia and exophorias, convergence insufficiency, accommodative dysfunction and dyslexia(5).

A sixty-two year old Caucasian female was referred to a Specsavers practice in New Zealand because she was experiencing dizziness and poor balance. She noticed that when she stood up she felt as though she would fall over but denied any nausea. In crowded spaces, she struggled to walk when there were other people surrounding her. These symptoms were present 5 months post-traumatic brain injury.

The referring hospital noted that the patient had difficulty maintaining balance and concluded that the patient would benefit from a neuro-optometric evaluation. A review of her medical history revealed that she had been involved in a minor car crash causing whiplash and temporary paralysis of the right side of the body. 5 years prior, the patient had suffered a concussion after falling backwards and hitting her occipital lobe. After multiple medical evaluations, including neuroimaging, no cause for her visual symptoms was found. The patient was concurrently under chiropractic care for neck pain as well as a physiotherapist and occupational therapist to try help improve balance and posture.

The initial examination showed 6/9, 6/7.5 and 6/6 distance acuity RE, LE and BE, respectively and near acuity was N5 BE with her habitual spectacles in place (plano/-0.25×140 RE and +0.25/-0.25 x 155 LE with a +1.50 add). Pupils were unremarkable and her confrontations and motilities were both full.

The manifest refraction showed hyperopia, astigmatism and presbyopia that was marginally different from her habitual spectacles. Her near phoria with manifest refraction was

8Δ

and distance phoria was 12Δ exophoria. Visual midline shift testing by passing a wand laterally before the patient determined that she had a shift in her concept of visual midline to the right. When walking, she leaned to the right and began to drift to the right.  Based on the measurement, horizontal yoked prism (1Δ BO RE and 1Δ BI LE) was trialled with the new refractive findings to shift the midline back to the centre. The patient was immediately able to bear weight on her left side while walking in a straight line and maintain her balance and posture. The assessment of ocular health was unremarkable. Updated spectacle lenses with the yoked prism (+0.25/-0.75 x 150 1Δ BO RE and +0.50/-0.50 x 160 1Δ BI LE and +2.00 add) was prescribed and she was scheduled for additional testing.

Further evaluation was then conducted to manage the disequilibrium experienced by the patient. Balance board testing was conducted whilst trialling various tinted filters in combination with the prescribed prescription to aid the patient. She found that Cerium C3 tint in combination with the yoked prism and the new prescription increased her comfort and sense of balance when walking around.

Two weeks after this initial visit, binasal occlusion was attempted. Scotch tape was applied to the nasal portion of the back surface of the patient’s lenses. She was then instructed to walk down the store hallway. She appeared more confident walking past others and moving through doorways. She also reported feeling less unbalanced. The patient was instructed to use the binasals during daily activities.

The following week, the patient reported that the binasals drastically helped improve her mobility and comfort when walking. She will continue to be seen yearly as vision therapy proved successful.

Divergence excess as an isolated binocular vision disorder was ruled out as a differential diagnosis on the basis that the patient hadn’t reported experiencing dizziness or diplopia prior to the brain injury. Divergence excess is defined as an exophoria or tropia that is larger at distance than at near. Although the patient met this criteria, the final diagnosis was post trauma vision syndrome because they exhibited concurrent symptoms including vertigo and a visual midline shift that were not present prior to the brain trauma.

Similarly, Ménière’s disease was ruled out as a potential diagnosis. Ménière’s is a disorder of the inner ear that is characterised by vertigo, tinnitus and nystagmus. Onset typically occurs between the ages of 40-60, with a higher prevalence found among females. Whilst the patient fit the disease demographic, she didn’t complain of any hearing loss or ringing in her ears and her motilities were full with no signs of nystagmus and as such the condition was ruled out.

Visual midline shift syndrome was first documented by Padula in 1996 who noted how changes to the ambient visual process following a traumatic brain injury altered the affected individual’s concept of the midline(6).

The visual system is comprised of two separate processes, focal and ambient(5). The focal process is neurologically involved in the functioning of the central vision through the macula. The ambient process utilizes the peripheral vision as an overall spatial orientation system, allowing individuals to orient themselves in space whilst providing general information that is used for balance, coordination, movement and posture(4,5). However, given a neurological accident such as a traumatic brain injury, the ambient visual process can change its concept of the visual midline if its ability to combine information from various parts of the sensory-motor feedback loop is diminished(8). Normally, sensory information from both sides of the body has to be paired through the kinaesthetic and proprioceptive systems with both ambient and vestibular information(4). However, in the case of a traumatic brain injury, information from one side of the body is altered. Since the ambient process functions in a relative capacity, it attempts to create a sense of balance when unilateral interference of information occurs by expanding its concept of space to one side. In doing so, an apparent expansion of space occurs on that side and an apparent compression of space occurs on the contralateral side. This ultimately leads to an imbalance when walking in affected individuals as the phenomena causes a shift in the concept of the visual midline, typically to the neurologically affected side(4,5).

Prisms are said to be yoked when the bases of both prisms point in the same direction in front of the eyes and have the same power.  A key scientific study conducted by Sheedy and Parsons in 1987 observed the postural changes and perceptual shifts induced by yoked prisms (2). They demonstrated that yoked prisms were able to counteract the amplification and compression of space that occurs in the ambient visual process after neurological trauma, causing the midline to shift to a more centred position. It was noted that yoked prisms enabled the affected individuals to shift their weight and increase the bearing weight on the affected side almost immediately.

When yoked prisms are introduced before the eyes of a patient experiencing visual midline shift syndrome, it forces the eyes to reorientate to look at the image of the object in a new position. This readjustment in the motor system sends information to the cortex that states that the sensory component must re-adapt itself to this new position in space. This in turn causes a re-orientation of the motor and sensory organisation in the cortex, effectively countering the visual distortion experienced by the individual (2,7).

Base left and right yoked prisms should be used in an attempt to re-establish lateral midline concepts. However, it is important to note that when prescribing yoked prisms, they should be used for 2-4 hours during the day. This doesn’t allow for total adaptation to the prism and will influence the to re-organise their sensory and motor function when the prism is not in place(2,8).

Binasal occlusion acts as “a persistent change in the patient’s central visual spacing,” forcing the patient to change the way that they experience the world, pertinently by making the patient more dependent on peripheral cues(10). Binasal occlusion involves occluding the binocular nasal field, thereby affecting binocular integration. Since this part of the visual field overlaps, it requires intense neurological demand and as such requires the maximum level of binocular integration in order to function appropriately(9). However, when a traumatic brain injury occurs, the integration of the binocular nasal field is the most challenging for the individual to produce a single, clear and stable image. As such, when the input from this portion is altered through occlusion, it often significantly relieves visual stress experienced by the patient by alleviating the confusion of attempting to organise this part of the visual field whilst simultaneously allowing the patient to process information from the peripheral visual field.

Furthermore, Gallup proposed that binasal occlusion works effectively in combination with yoked prisms as it allows the peripheral visual fields to become more stimulated, causing greater awareness of space and further stimulation of the ambient visual processing system(3). Since binasals act as a constant and consistent reminder interjected between he affected individual and their visual environment, even when not consciously noticed, it further helps to organise visual input and relieve visual input.

Post trauma vision syndrome and visual midline shift syndrome have been found to have a high prevalence among individuals who have suffered a traumatic brain injury. Many individuals who have the conditions are severely affected by their inability to match information from their visual and motor centres to achieve normal posture and balance. As such, both post trauma vision syndrome and visual midline shift syndrome require the ambient visual process to be re-organised.

The value of using yoked prism and binasal occlusion together to treat individuals with post-traumatic brain injury has been demonstrated on an individual basis. After a traumatic brain injury, many associated visual dysfunctions experienced by the affected individual are related to the ambient system’s inability to process and organise spatial information. However, incorporating yoked prism provides the patient with the opportunity to shift the concept of the visual midline, helping them to regain their posture and sense of position in space. Similarly, using binasal occlusion as part of the therapeutic regimen provides the individual with the opportunity to experience a change in their visual environment that creates the potential for improved symptoms. Both yoked prism and binasal occlusion should be considered when managing post-traumatic brain injury patients to help them interact with their world in a productive and effective manner.

BIBLIOGRAPHY:

1. Bansal S, Han E, Ciuffreda KJ. Use of yoked prisms in patients with acquired brain injury: a retrospective analysis. Brain Injury. 2014;28(11):1441-6.
2. Caldwell CH, Reyes-Cabrera E. A deliberate set of examinations and the application of yoked prisms in the treatment of visual midline shift syndrome: a case report. Optometry and Visual Performance. 2015;3(6):291-97.
3. Gallop S. Binasal occlusion-immediate, sustainable symptomatic relief. Optometry and Visual Performance. 2014;2(2):74-78.
4. Hudac CM, Kota S, Nedrow JL, Molfese DL. Neural mechanisms underlying neurooptometric rehabilitation following traumatic brain injury. Eye brain. 2012;4:1-12.
5. Liebowitz HW. And Post RB. The two modes of 28: processing concept and some implications. In: Beck JJ, ed. Organisation and Representation in perceptions. Erlbaum, Hillsdale, NJ, in press.
6. Padula WV, Argyris S, Ray J. Visual Evoked Vision Syndrome (PTVS) in patients with traumatic brain injuries (TBI). Brain injury. 1994;8(2):125-133.
7. Padula WV, Subramanian P, Spurling A, Jenness J. Risk of fall (RoF) intervention affecting visual egocenter by gait analysis and yoked prisms. Neurorehabilitation. 2015;37(2):305-14.
8. Padula WV. A behavioural vision approach for persons with physical disabilities. Optometric Extension Publishers, 1988.
9. Proctor A. Traumatic brain injury and binasal occlusion. Optometry and  Vision Science. 2009;40:45-50.
10. Yadav N, Ciuffreda K. Effect of binasal occlusion (BNO) and base-in prisms on the visual-evoked potential (VEP) in mild traumatic brain injury (mTBI). Brain injury. 2014;28(12):1568-1580.