Dr Kusy Suleiman¹*, Dr Omar Mostafa²*, Dr Yusuf Abdallah³, Mr Thomas Ressiniotis⁴

¹ Academic Foundation Year 2 Doctor, Ophthalmology Department, Sandwell and West Birmingham NHS Trust ^{Contact author}

² Foundation Year 1 Doctor, Acute Medical Unit, Walsall Manor Hospital ^{Contact author}

³ Ophthalmology ST1 Doctor, Heartlands Hospital, University Hospital Birmingham. ^{Contact author}

⁴ Consultant Ophthalmologist and Royal College of Ophthalmology Tutor, University Hospitals Birmingham NHS Trust.

*Joint first author

Keywords: Visual Impairment, Epidemiology, Services, Management.

Key Points:

• Patient education is key: ensure patients are aware of benefits and support services available to people with partial sight or blind registration.
• Aid patients in maximising whatever residual vision they have left.
• Ensure interventions and adequate provisions are put in place for children and adults with visual impairment in order to maximise outcomes and independence.

Abstract

This article aims to introduce visual impairment in a medical context to a target audience of medical students and junior doctors. The paper aims to depict what visual impairment is, present both global and national epidemiological data, as well as showcase the potential implications visual impairment and blindness have on affected individuals.

The article also aims to shed light on visual impairment in the UK population. It provides a snapshot of the implications and social/state-related management revolving around both visual impairment and blindness, in addition to what national services are available for those affected. Regarding management, the article pays particular attention to vision aids, developmental and educational interventions for kids, as well as both the National Registers of Partial Sight and Blindness (NRPSB) and Statement of Educational Needs (SEN). The article is concluded by a few salient learning points.

Background and Introduction

Visual Impairment (VI) is a fundamental aspect of ophthalmology, and although often undertaught, students and clinicians both need to have awareness around it. VI is an umbrella-term used to describe a wide-spectrum of loss of vision. Approximately 9 in 10 of visually impaired and blind individuals reside in the developing world, with cataract being a leading cause, whilst only 1 in 10 live in the developed world^1,2.

The World Health Organisation (WHO) defines blindness as having a Visual Acuity (VA) of less than 3/60 in the better eye, and low vision as a VA less than 6/18 but greater than or equal to 3/60^2,3. In contrast, UK Low Vision Services Consensus Group defines low vision as ‘impairment of visual function which causes restriction to everyday life and which cannot be corrected by conventional spectacles, contact lenses, or medical intervention’⁴. It is important to note that visual function is more than just distance-VA, as other factors such as near-VA, Contrast Sensitivity and Visual Field (VF) are equally as important⁵. Table 1 highlights the 4 elements above used to assess visual function.

Table 1: Assessment of Visual Function⁵

Distance-VA	Gold Standard: LogMAR chart. May use Snellen Chart
Near-VA	Bailey-Lovie Near chart (runs from N2.5 to N80)
Contrast sensitivity	Not commonly assessed in clinical practice. May utilise a Pelli-Robson chart. Poor contrast sensitivity is associated with falls in the elderly population.
Visual Field (VF)	VF quality can severely impact daily function despite having 6/6 central vision. Mobility and reading difficulties are usually tell-signs of visual field impairment.

Epidemiology

Approximately one adult becomes blind every 5 seconds, and one child becomes blind every 60 seconds, worldwide⁶. In the UK, roughly 3% of the population suffers with some degree of non-correctable VI. Of those, approximately two-thirds qualify for VI registration due to severity of their sight loss⁵. The commonest cause of blindness in the working age group (16-64) is diabetic retinopathy, with an incidence of approximately 13 per 100,000 per year. Further, Age-related Macular Degeneration (AMD) accounts for more than half of VI and blind registrations in USA, Western Europe and UK⁶.

Blindness and VI also carry a huge economical toll – in 2013, the total estimated burden of those in the UK alone exceeded GBP£28 billion⁷. This can in part, be explained by the economic impact reduced vision has on individual members of working-age in a household. For example, a person with a VA of 6/12 or worse in their better eye is automatically excluded from eligibility to join or partake in several occupations: police force⁸, driving – including both bus and taxi driving⁹, fire brigading¹⁰ as well as piloting¹¹.

Registering as Visually Impaired in the UK

The National Registers for Partial Sight and Blindness operates on a voluntary-based certification. However, certification is the main medium to access statutory benefits and relevant social services.

This slightly differs for children, as it is a UK-legal requirement to regularly assess, and review educational needs of children with Severe VI. This is typically done via a Statement of Educational Needs, or SEN for short (Visually Impaired Assessment Team -VICAT in Ireland). The SEN/VICAT establishes the support, facilities and educational placement provided by the government to cater for the individual child’s needs. These can range from attending mainstream schools with an advisory teacher to schools/colleges for the visually impaired and residential schools for children with special needs⁶.

Generally, registration of VI in the UK serves a threefold function⁵:

1. Officially recognises an individual’s VI.
2. Aids in identifying patients suitable for assistance due to disability.
3. Helps government, social services and local eye services better understand distribution and extent of VI in differing communities.

Help aimed to assist VI individuals lead an independent life is available at both the local government level (social services) and voluntary organisations, such as the Royal National Institute of Blind People (RNIB)¹². In England, registration is achieved by an ophthalmologist completing a Certificate of Vision Impairment (CVI). Similar forms are utilised in both Scotland and Northern Ireland to register VI¹³. To be eligible for CVI registration, one must meet criteria for either ‘sight-impaired/partially sighted’ or ‘severely sight impaired/blind’, summarised in Table 2⁵.

Table 2: CVI Categories of Eligibility⁵

Sight-Impaired/ Partially Sighted

There is no legal definition.   The UK Department of Health summarises eligibility for this category as one of: VA of 3/60 – 6/60 with normal VF.VA of 6/60 – 6/24 with aphakia, media opacities, or contraction of the VF.VA of 6/18 or better but with severe field loss; advanced glaucoma, retinitis pigmentosa, or large visual defects such as hemianopias all qualify.

Severely Sight Impaired/ Blind

There is a legal definition.   The National Assistance Act (NAA) 1948 defines this as: ‘so blind that they cannot do any work for which eyesight is essential’14.   Eligibility for this category is conventionally summarised as either: VA of less than 3/60 with normal VF.VA of 3/60 – 6/60 with a very contracted VF.VA of  6/60 or better with a very contracted VF, especially when compounded with a significant inferior field loss; bitemporal/homonymous hemianopias are usually excluded from this, unless the central VA is worse than 6/18.

Benefits of Registering VI in the UK

For individuals, registering as visually impaired comes with a range of benefits. For instance, children aged <16 years of age benefit from a Disability Living Allowance (DLA), working age (16-64) benefit from Personal Independence Pay (PIP), and elderly (65+) benefit from Attendance Allowance (AA) to help with mobility and personal care. In addition, there are other tax reliefs and allowances such as: income support systems in place, working tax credit (if working >16 hours with low-income), Employment and Support Allowance (ESA) for those of working age but unable to work and council tax disability reduction scheme⁵.

Additionally, blind and partially sighted people are also eligible for an array of community care services and local council assistance in the UK, including home care, mobility training, equipment, and home modifications. Other range from free NHS sight tests and prescriptions travel concessions, exemption from BT directory enquiries and free postage on ‘articles for the blind’⁵.

Additional Assistance

As vision is arguably the most precious of our 5 senses, it not uncommon for patients with VI to face psychological difficulty. They are also more prone to social isolation, an increased morbidity and mortality, and overall reduced quality of life.

In addition to low-vison aids, other forms of help exist. From devices that detect when a cup is filled, guides that help with placing signatures on cheques and telephones with large number buttons, visually impaired people can be enabled to live as normal a life as possible¹³. For some patients, providing them with a guide dog or even training on how to use a cane greatly improves their mobility¹⁵. Furthermore, Eye Clinic Liaison Officers (ECLO) are crucially important and helpful, as they form a link between hospitals and social services. Additionally, ECLOs both educate patients and provide them with practical and emotional support going forwards¹².

References

1. Bourne RRA, Flaxman SR, Braithwaite T, Cicinelli MV, Das , Jonas JB, et al. Magnitude, temporal trends, and projections of the global prevalence of blindness and distance and near vision impairment: a systematic review and meta-analysis. The Lancet Global Health. 2017 Aug 2;5(9):e888-97. doi: 10.1016/S2214-109X(17)30293-0
2. Blindness and Vision Impairment [Internet]. World Health Organisation (WHO). 2019 [cited 17 June 2020]. Available from: https://www.who.int/news-room/fact-sheets/detail/blindness-and-visual-impairment
3. Towards a Common Language for Functioning, Disability and Health ICF World [Internet]. World Health Organisation (WHO). 2002 [cited 19 June 2020]. Available from: https://www.who.int/classifications/icf/training/icfbeginnersguide.pdf
4. Low Vision Services Consensus Group. Low Vision Services: Recommendations for future service delivery in the UK. London: The Royal National Institute for the Blind (RNIB). 1999.
5. BMC Health Services Research volume. 2018 Jan 11;18(63). doi: 10.1186/s12913-018-2836-0
6. https://www.policenow.org.uk/wp-content/uploads/2019/08/Eyesight-requirements.pdf
7. https://www.gov.uk/driving-eyesight-rules
8. https://www.fireservice.co.uk/recruitment/eyesight/
9. https://www.caa.co.uk/Aeromedical-Examiners/Medical-standards/Pilots-(EASA)/Conditions/Visual/Visual-system-guidance-material-GM/
10. Blindness and Vision Loss [Internet]. NHS.UK. 2018 [cited 20 July 2020]. Available from: https://www.nhs.uk/conditions/vision-loss/
11. National Assistance Act 1948 [Internet]. Legislation.gov.uk. 2019 [cited 22 July 2020]. Available from: https://www.legislation.gov.uk/ukpga/Geo6/11-12/29
12. Guide Dogs UK [Internet]. Guide Dogs Site. 2020 [cited 22 July 2020]. Available from: https://www.guidedogs.org.uk/