Blindness

Definition of blindness

The Department of Health divides visual impairment into two groups:

Sight impaired (SI—formerly partially sighted) and

There is no legal definition of sight impairment but guidelines state that a person is SI if he or she is ‘substantially and permanently handicapped by defective vision caused by congenital defect or illness or injury’ (Department of Health, 2007). However, the term ‘SSI’ is legally defined and applied to any person ‘so blind as to be unable to perform any work for which eyesight is essential’ [National Assistance Act 1948 Section 64(1)]. It is important to note that this definition refers to ‘any work’ for which eyesight is essential and not just the patient's own particular occupation.

In clinical terms, certification for being SI or SSI is mainly based on visual acuity and visual fields. This is summarized in Table 1.

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Table 1.

Requirements for certification as SI/SSI

SI	SSI
3/60 to 6/60 Snellen with full visual fields	Less than 3/60 Snellen
Up to 6/24 Snellen with moderate contraction of visual fields (or opacities in media or aphakia)	3/60 to 6/60 Snellen with very contracted visual fields
6/18 Snellen or better with gross defect in visual fields	6/60 Snellen or better with very contracted visual fields, especially inferior field loss

Common causes

The common causes of visual impairment in England and Wales can be identified from certification records (Figs. 1 and 2). For SSI patients, the most common causes in order of prevalence are

degeneration of the macula and posterior pole, which largely comprises age-related macular degeneration (58.6% of registrations)

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Figure 1.

Main causes of severe sight impairment in England and Wales: Certifications April 2007–March 2008.

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Figure 2.

Main causes of sight impairment in England and Wales: Certifications April 2007–March 2008

The picture is similar for SI patients.

Clinical assessment

The ophthalmic history for a patient presenting with visual loss should cover the following areas:

history of presenting complaint

In the history of presenting complaint, gather information regarding the onset, quality and extent of visual loss as well as associated ocular symptoms. This can help with formulating a diagnosis. For example, sudden profound loss suggests vascular aetiology, whereas distorted central loss of vision suggests macular disease.

The past medical history and social history may also shed light on the cause of visual loss. For example, diabetes mellitus causes retinopathy and cataracts, but cardiovascular disease or risk factors for cardiovascular disease may lead to retinal vascular occlusions. Certain medications have also been shown to cause retinopathy (such as chloroquine) and some conditions run in families (such as glaucoma).

The ophthalmic examination in the primary care setting should comprise the following assessments as appropriate:

Visual acuity (including pinhole)

Visual acuity that improves with a pinhole may suggest refractive error as a cause of visual loss. An absent red reflex can indicate a cataract; visual field examination may pick up visual loss resulting from cerebrovascular disease. Direct ophthalmoscopy can identify retinopathy, such as diabetic retinopathy, as a cause of visual loss, with typical clinical features, such as microaneurysms, haemorrhages, exudates and cotton wool spots.

Previous InnovAiT articles on sudden visual loss (Harding, 2008), glaucoma (Simpson, 2011) and age-related macular degeneration (Newsom, 2008) describe in more depth the clinical features that characterize many of the conditions that can cause visual impairment.

Psychological and social problems

Loss of vision can have a huge impact on a patient's life. Some patients may struggle to come to terms with it, and many will experience reactions and emotions similar to that seen with bereavement, such as shock, denial, anger, fear and sadness. They may be anxious about falls and accidents and no longer feel safe to be alone. Others may feel that they have to change their job and hobbies as a result of their sight impairment. Relatives and friends may also have similar responses as they too adapt to the changes.

These people may benefit from both practical and emotional support. GPs can refer patients to counsellors through the National Health Service (NHS) and can direct patients to other sources of support, such as the Royal National Institute for Blind People (RNIB), which offers an emotional support telephone service. The RNIB also help people who suffer from sight impairment find and retain jobs and gives information about hobbies and interests. Furthermore, it offers a wide range of products that can be purchased to help individuals live an independent life, such as magnifiers, televisions (TVs) and talking watches.

Practical support

There are a number of practical measures and environmental adaptations that can be undertaken to support patients who have visual impairment. GPs need to be aware of these:

the visual acuity that remains should be optimized by up-to-date refraction; patients should be encouraged to visit an optician

Visually impaired individuals and their families should be encouraged to access support through social services and through local support organizations. Local societies for people with sight problems can be found through the RNIB. Low vision clinics based either in the hospital eye units or in the community can be very helpful sources of advice and equipment.

Driving

The DVLA has standards for fitness to drive for people with visual disorders. In order to drive, a person must be able to ‘read in good daylight (with the aid of glasses or contact lenses if worn) a registration mark fixed to a motor vehicle and containing letters and figures 79 mm high and 50 mm wide [i.e. post 1.9.2001 (plate) font] at a distance of 20 m or at a distance of 20.5 m where the characters are 79 mm high and 57 mm wide [i.e. pre 1.9.2001 (plate) font]’ (DVLA, 2011). This corresponds roughly to 6/10 on the Snellen visual acuity chart.

For visual fields, the DVLA states that a driver must have ‘a field of at least 120° on the horizontal’ with ‘no significant defect in the binocular field which encroaches within 20° of fixation above or below the horizontal meridian’ (DVLA, 2011). Further, more stringent requirements are placed on those who hold Group 2 licences (which includes large lorries and buses) and racing drivers.

There are exceptional circumstances for which the DVLA may permit people to drive who do not satisfy these criteria. However, registration for sight impairment or severe sight impairment will normally be regarded as incompatible with holding a driving licence and should be notified to the DVLA.

The onus is on the patient to contact the DVLA if he or she develops significant changes to vision. GPs may encounter ethical issues should a patient refuse to do so. They should always document that they have discussed safety and advised such patients to inform the DVLA. In cases where a patient continues to drive despite advice not to, GPs are advised to contact their defence organization for advice.

Referral to social services

The first step for patients to access support from social services is often through a health and social care assessment. This is carried out by a specialist and looks into the individual needs of each person. Assistance from social services includes home care (cleaning and shopping) and disability equipment and adaptations to homes as appropriate. Social services can also put people in touch with rehabilitation officers who can help them to become more independent with their daily activities, mobility and communication.

Referrals for social services assessments can be made in one of three ways:

Certificate of Vision Impairment (CVI)—as well as formally certifying a person as SI/SSI, the CVI also automatically acts as a referral for a social care assessment

Visual impairment registration

Traditionally, the role of registration for visual impairment is 3-fold:

to formally recognize the individual's sight loss

Currently, there are two levels of registration: SSI and SI. The signature of a consultant ophthalmologist on a CVI is required before registration of visual impairment can be offered.

Benefits of registration for SSI

Registering sight loss can be a ‘passport’ to getting concessions and benefits. It is helpful for GPs to know about these benefits, not only so that they can guide patients towards getting financial support but also because they may also be required to assess patients and sign application forms.

People registered SSI are entitled to claim Blind Person's Allowance. This is extra tax-free income that is added to the standard tax-free Personal Allowance. If the individual does not have enough taxable income, then he or she may be able to transfer this allowance in part or in whole to a spouse or civil partner. This allowance can be claimed by contacting HM Revenue & Customs.

Households with a SSI adult or child can also claim for a 50% reduction in their TV licence fee. This can be claimed from TV licensing.

In addition, persons registered as SSI automatically qualify for a Blue Badge. This scheme is administered by local authorities and allows those with disability to park near to where they need to go.

The Royal Mail also operates an ‘Articles for the Blind’ service that allows registered SSI senders or recipients to send certain items free of charge, such as printed material in large print and braille items. Items can also be collected by Royal Mail free of charge if the user is blind and cannot go to a post office.

The British Wireless for the Blind Fund is a registered charity that offers audio equipment (radios/compact disc players) specifically designed for those with sight loss. Products can be purchased directly or obtained through a free permanent loan scheme via local authorities. The Telephones for the Blind Fund is another registered charity that can only be accessed via social services. It provides full telephone installation costs and a large proportion of line rental costs for patients who are registered SSI and who cannot meet these costs themselves.

Benefits of registration for SSI or SI

There are several NHS entitlements available for those with registered visual impairment. These include free eye tests, vouchers towards certain types of glasses and free medical prescriptions if patients cannot leave their homes unaided.

Concessions are also available for travel and leisure although individuals may need to hold specific cards to claim these, such as the Disabled Person's Railcard and the Cinema Exhibitor's Association Card. Reduced price entry to museums, exhibitions, theatres and concert halls may also be available for those with registered visual impairment. Individual venues can be contacted for details. Free 195 directory enquiries can be applied for from British Telecom and GPs may be required to countersign the form.

Welfare benefits

There are a number of welfare benefits that patients with sight impairment and severe sight impairment may apply for but for which they are not automatically eligible. These are listed in Table 2. Considerations may be needed when applying for benefits, for example, claiming for one type of benefit may impact on other types. The RNIB offers a helpline where advice and further information may be obtained.

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Table 2.

Welfare benefits

Attendance allowance	Benefit that can be applied for by those over 65 who require help during the day or night or who need watching over to avoid danger.
Disability Living Allowance	Tax-free benefit that can be claimed by those under 65 who have a physical or mental disability that results in a need for help with care and/or mobility.
Carer's Allowance	Benefit designed to help those who care for someone who is disabled (e.g. visually impaired). It can be claimed by those who are over 16 and spend at least 35 hours a week caring for a person.
The Employment and Support Allowance	Provides financial support for those who have an illness or disability that severely affects their ability to work.
Tax credits	Income-based benefits that can be claimed if a person is looking after children (Child Tax Credit) or is working but with a low income (Working Tax Credit). Both components of tax credits contain a disability element, which applies to those who are registered with visual impairment.

Overcoming obstacles to effective health care

Most SI and SSI patients would like access to health information and regard GPs and the Internet as their main sources of information. However, the majority of visually impaired patients are not asked about the reading format they require and cannot read the information they receive from their GPs. This can have significant consequences for patient health. Examples of this include compromised patient privacy and independence (needing to ask others for help with reading information), reduced safety (with regard to prescribed medication) and missed appointments.

However, measures can be taken to overcome barriers to accessible health information. These involve both patients and health professionals.

Patients need to be empowered to demand information in accessible formats. This can be done through education about legislation such as The Equality Act 2010, which protects disabled people and prevents discrimination against them in areas such as access to services. The Equality Act mandates organizations to make adjustments for the disabled, such as providing information in large print text.

Health care professionals should also be educated about the information needs of the visually impaired and about the consequences of inaccessible information. Individual needs assessments should be carried out and records of individual reading requirements should be kept for each patient. This can be done for example by performing the assessment whenever a new visually impaired patient registers with a practice. Records can be electronically kept with electronic prompts to consider patient requirements whenever files are opened.