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A Global Public Health Perspective: Facilitating Access to Assistive Technology

du Toit, Rènée, PhD, MPH1*; Keeffe, Jill, PhD2; Jackson, Jonathan, PhD, MCOptom, FAAO3; Bell, Diane, PhD, MBA4; Minto, Hasan, DipOpt, FAAO5; Hoare, Philip, CIPS (Foundation)6

doi: 10.1097/OPX.0000000000001272
PERSPECTIVES

SIGNIFICANCE Clinicians should not overlook vulnerable populations with limited access to assistive technology (AT), the importance of collaboration in multidisciplinary teams, advocacy for enabling environments, and supportive health systems. Resources, a model of care, and recommendations can assist clinicians in contributing to changing attitudes, expanding knowledge, and improving the lives of many.

The increasing availability of innovative advances in AT can immeasurably enhance the quality of life of people with disabilities. Clinicians will undoubtedly welcome the prospect of having cutting-edge AT available to prescribe to individuals who consult them. Arguably, though, the development of innovative strategies to improve access to AT, especially to underserved people “left behind,” is equally urgent. Current efforts are inadequate, with millions of people with disabilities not being reached. Particularly at risk are women, children, and the elderly, as well as poorer people who live in resource-poor and remote areas, especially in low- and middle-income countries. Not only must physical access be facilitated, but also quality services must be available. Good-quality, affordable AT, which is appropriate and acceptable to the user, would ideally be provided by competent personnel, working in multidisciplinary teams, offering comprehensive, person-centered services, including rehabilitation, fully integrated into the various levels of the health system. Clinicians can contribute to improving access to quality services, participate in initiatives aiming to increase the knowledge of health personnel and the public, engage in advocacy to change attitudes, influence legislation, and raise awareness of universal health coverage—ultimately facilitating access to AT for all.

1Independent Public Health Consultant, Pretoria, South Africa

2L. V. Prasad Eye Institute, Hyderabad, India

3Belfast Health and Social Care Trust, Cathedral Eye Clinic, Belfast, United Kingdom

4University of Stellenbosch, Stellenbosch, South Africa

5Brien Holden Vision Institute, Karachi, Pakistan

6International Agency for the Prevention of Blindness, London, United Kingdom *dutoitrenee@gmail.com

Submitted: January 31, 2018

Accepted: June 19, 2018

Funding/Support: None of the authors have reported funding/support.

Conflict of Interest Disclosure: None of the authors have reported a conflict of interest.

Author Contributions: Conceptualization: RdT; Methodology: RdT; Writing – Review & Editing: RdT, JK, JJ, DB, HM, PH.

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The assistive technology featured in this issue of Optometry and Vision Science has the potential to enhance the functional vision and quality of life of many people who are visually impaired, should they be among those fortunate enough to be able to access this assistive technology. Worldwide, an estimated 80 million people have low vision.1 These include about 6 million children, 4.8 million in low- and middle-income countries.1 An estimated 466 million people worldwide have disabling hearing loss, 34 million of which are children, with this number expected to reach 630 million by 2030.2,3 In addition, 1.1 billion young people (12–35 years) are at risk of hearing loss owing to exposure to noise in recreational settings.2 More than a billion people have some form of disability; of these, an estimated 110 million to 190 million adults have significant difficulties in functioning.4

People with disabilities have less access to education and are more likely to be out of school or to leave school before completing primary or secondary education. Furthermore, they have less access to health care services and therefore experience unmet health care needs.5 In many countries, less than 10% of people who need low vision aids,6 and less than 3% of those in need of hearing aids,7 are able to access these. People with comorbidities have more complex needs, yet for older people (≥65 years) with visual impairment, who are more likely to have comorbidities,8,9 vision, depression, and hearing screening are not usually seen as associated. In addition, the prevalence and extent of the impact of concurrent vision and hearing loss have largely not been quantified. This contributes to limited awareness and resources available to the older adult population with dual sensory impairment.10

This article seeks to highlight the challenges in gaining access to appropriate assistive technology that are faced by vulnerable populations, with disability being more common among women, older people, and children as well as adults who are poor, and also those who live in low- and middle-income countries. It also seeks to draw attention to the need for eye health providers to look beyond providing care that is restricted to their clinical specialty, to linking with other service providers and other disabilities. Furthermore, the article seeks to make recommendations to eye health care providers to enable them to contribute to universal health coverage, which includes rehabilitation and the provision of assistive technology.

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ASSISTIVE TECHNOLOGY AND ASSISTIVE PRODUCTS

Assistive technology has been defined as “…any item, piece of equipment, or product system, whether acquired commercially off the shelf, modified, or customized, that is used to increase, maintain, or improve functional capabilities of individuals with disabilities….”11

The World Health Organization defines the primary purpose of assistive products as “… to maintain or improve an individual's functioning and independence to facilitate participation and to enhance overall well-being.” They estimate that, currently, only 1 in 10 people in need has access to assistive technology.12

A goal of low vision rehabilitation is to “…reduce the impact of visual impairment and minimise disability through one or more concurrent approaches.”1,13 One of these approaches is the provision of assistive technology. The continued use and benefit of assistive technology to the user depend not only on successfully matching the specific assistive technology with the user's requirements but also on the user's perception of the assistive technology. A team providing support, both social and psychological; training in the use of assistive technology; and environmental adaptations that are tailored to the person's needs can reduce the impact of disability, enhance one's sense of self-management, and thus significantly improve the user's success with assistive technology.13 Across the sector, case studies and clinical anecdotal evidence provide strong support for such a person-centered multidisciplinary model of care; it has therefore become the norm, despite the lack of more formal rigorous evidence.14

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LOW VISION REHABILITATION SERVICES

Availability and Accessibility of Services

Although there is considerable variation between regions and countries, only 5 to 10% of people who need low vision rehabilitation services are estimated to access these. A recent global survey reported that 36% of countries, more frequently lower-income countries, did not have low vision rehabilitation services. Low vision rehabilitation services where these existed were, however, mainly monodisciplinary, sometimes providing a service such as rehabilitation, but more frequently providing only clinical care. This is typically limited to prescribing an assistive product, providing little or no support in training in how to use these and create an enabling environment where these can be optimally used to maximize their potential or in sensitization of families and communities. In addition, even in countries that reported the presence of low vision rehabilitation services, coverage was poor: less than or equal to 10% in 34% of countries and 11 to 50% in 19% of countries. Poor coverage was more likely in countries that are less urbanized. Low vision rehabilitation services were mainly provided at secondary and tertiary levels and in urban areas.6

Lack of services and the sparse geographical distribution of existing services consequently create major impediments to access that includes cost, time, and problems with transport to travel to service sites. In addition, other barriers such as age, sex, language, poor referral rates, social stigma, and lack of diagnosis and knowledge about services all negatively impact on service uptake. This will have a particularly negative impact on people who have low incomes, reside in rural areas, and are elderly or have multiple disabilities, as well as women, children, ethnic minorities, and refugees. Also deficient, mostly owing to geographic distribution of services, or the lack of awareness about low vision services among health care personnel, are effective referral systems to provide continuity of care. Exacerbating the challenges to access is the fact that low vision rehabilitation services are often stand-alone and not integrated. People may be expected to attend multiple appointments at different locations, which obviously adds to their costs and to their caregivers' burden. Although these factors are more likely to present challenges to access in lower-income countries, these exist to some extent in higher-income countries.13,15–22

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Quality of Care and Competency of Personnel

The general lack of awareness about low vision rehabilitation services and assistive technology among health care, and even eye care, practitioners and consequent lack of referrals act as yet another barrier to access assistive technology. Furthermore, for the proper prescription and fitting of assistive technology and for user training, support, and follow-up, competent personnel, such as optometrists, ophthalmologists, orthoptists, nurses, occupational therapists, social workers, counselors, teachers, rehabilitation, and orientation and mobility workers, ideally working as a multidisciplinary team, are required. Without this, assistive technology is often of no benefit or may be abandoned. Understandably, the more sophisticated the assistive technology, the higher will be the need for training and support, for both users and personnel.13,15,19

To understand the assistive technology personnel landscape, context-specific needs assessments are required to shape and strengthen credentialing frameworks through competencies and certification, acknowledging specific as well as general skill mix requirements.23 Given the overlap in competencies between cadres, competency-based curricula should be developed for groups such as eye care workers, health care workers, and those involved in medical studies, rather than for specific professional roles.20

Sufficient, competent human resources, providing comprehensive care, distribution and provision of multidisciplinary low vision rehabilitation services, and sustainable funding, have been identified as the most important predictors associated with better coverage of low vision rehabilitation services.24 Because it would be counterproductive to address any of these factors in isolation, a systems approach is recommended to strengthen low vision rehabilitation services and the availability of assistive technology.20 Furthermore, ensuring assistive technology is available and accessible and provided by competent personnel is essential but alone is not sufficient. For people with a disability to use assistive technology, it must also be appropriate, affordable, and of acceptable quality and appearance.

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ASSISTIVE TECHNOLOGY

Affordability and Appropriateness of Assistive Technology

Many countries have no national service delivery supplying assistive technology, necessitating purchasing directly from a pharmacy, private clinic, workshop, or the Internet. Others who cannot afford this option must rely on erratic donations or charitable services, which often focus on delivering a limited range of assistive products. These are often not appropriate for the user or the context and lack mechanisms for maintenance, repair, and follow-up. Refurbishment options should also be part of the service delivery process.25

Assistive technology that uses the latest and sophisticated technology is likely to be less accessible by virtue of cost. Even free or low-cost assistive technology would, however, face similar challenges as the distribution of Ivermectin donated by the Merck Mectizan Program. These have been identified as issues of infrastructure, transparency, distribution, logistics, partnership, and sustainability to ensure long-term health benefits.26

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Acceptability and Appropriateness of Assistive Technology

The users' perception of the assistive technology and/or the sociocultural environment, such as taboos, stigma, and misconceptions, and peer and societal pressure, prohibit the use of, for example, telescopes, or even spectacle wear, particularly by young women.13

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ENABLING FACTORS

Available Resources

The World Health Organization Global Cooperation on Assistive Technology Initiative has developed the Priority Assistive Products List and, similar to the World Health Organization Model List of Essential Medicines, is to be used to create awareness among the public, mobilize resources, and stimulate competition and act as “…a catalyst in promoting access to assistive technology,” “…a model from which to develop a national priority assistive products list, and a resource to “… provide guidance for procurement and reimbursement policies, including insurance coverage.”27 There is an urgent need for both the development of international standards for all priority assistive products as listed on the World Health Organization Priority Assistive Products List as well as guidance on the procurement of good-quality, fit-for-purpose assistive products. On January 26, 2018, at the World Health Organization Executive Board meeting, member states agreed on the wording of a draft resolution to increase access to assistive technology and recommended that it be adopted during the World Health Assembly between May 21 and 26, 2018. This will certainly serve to strengthen the work of Global Cooperation on Assistive Technology in achieving its objective.

Another valuable resource that includes some assistive products identified by Global Cooperation on Assistive Technology is the International Agency for the Prevention of Blindness Essential List for Low Vision Services.28,29 This list includes the Global Cooperation on Assistive Technology assistive products as part of a broad range of optical and assistive products, screening and diagnostic equipment, and instruments that are recommended by the International Agency for the Prevention of Blindness Low Vision Work Group as appropriate for each of the three levels of care: primary/community health care providers, trained eye health professionals, and low vision specialists. This Essential List is available as a free resource and can be downloaded from the International Agency for the Prevention of Blindness Standard List Web site.30 Eye health providers from low- and middle-income countries can use the Standard List to assist them to source and compare eye health products from dependable suppliers and guide their procurement decisions so that they obtain the most cost-effective and appropriate equipment, devices, and consumables.

The International Agency for the Prevention of Blindness Low Vision Work Group has produced guidance on low vision curricula for cadres such as ophthalmologists, optometrists, teachers, and community-based rehabilitation workers. These can be used to inform both pre-service and continuing education and are also available on the International Agency for the Prevention of Blindness Web site.31

The Hong Kong Society for the Blind Vision 2020 Low Vision Resource Centre supplies a broad range of good-quality, affordable low vision assistive technology and diagnostic equipment.32

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RECOMMENDATIONS

A Person-centered Model for Establishing/Strengthening Low Vision Rehabilitation Services

Good-quality evidence about optimum service delivery models, or about which services are most cost-effective, is generally insufficient, especially from lower-income countries.13,14 Drawing from various models of low vision rehabilitation services, that is, the World Health Organization–tiered model,20,22 the optometry-focused integrated model for Canada,16 and the Comprehensive Multidisciplinary Vision Rehabilitation Model for ophthalmologists (United States),33 Table 1 describes some of the health system building blocks of a person-centered model of low vision rehabilitation services. The model may be adapted to accommodate the country context, for example, the competency, numbers, and distribution of eye and general health care personnel available; the country's definition of health service levels; and the regulatory environment.

TABLE 1

TABLE 1

In general, however, in countries or areas with no or few low vision rehabilitation services, a feasible starting point is to strengthen the secondary level to provide “add-on” services, integrated into existing eye care services21,34 (Table 1). Secondary level services are estimated to be able to meet the needs of 50%22 to 70%34 of the low vision population and will provide a bridge between primary- and tertiary-level low vision rehabilitation services, when these are established.21,34 Also, viable secondary-level low vision rehabilitation services may be accomplished with relatively simple and affordable interventions such as evaluating the low vision component of specialist eye health cadres training (e.g., optometrists, ophthalmic nurses, or clinical officers) to ensure they acquire appropriate competencies. Furthermore, clinical personnel need to be equipped with appropriate vision testing charts and range of magnifiers. They also need to recognize the importance of establishing/renewing links with other health, rehabilitation, education, and social service providers.21,34

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ADVOCACY TO IMPROVE ACCESS

Eye health providers can contribute to universal health coverage through advocacy in international communities and have an important role in enhancing the ability of individuals with disabilities to access assistive technology, enabling them to pursue education and vocations, participate in and contribute to a community, accomplish activities of daily living, and be well. Eye health providers need to work collaboratively in multidisciplinary teams to provide support for all disabilities, create an enabling environment, and bring about attitudinal change.13 They can, for example:

  • 1. Assist in empowering people with a disability to contribute to:
    • Awareness-raising campaigns about the availability of low vision rehabilitation services and to amend perceptions, such as “nothing can be done for people with low vision”;
    • Maximizing their functioning by providing information, for example, about their own health condition and services available to them, such as their rights to training and peer support to enhance mobility and performance of activities of daily living with the use of assistive technology, and mechanisms for complaints;
    • Planning and implementing policies and programs that support more holistic person-centered services for people with a disability;
    • Encouraging appropriate and healthy collaborations between the government and the private sector.18
  • 2. Advocate for accessible comprehensive care for people with disabilities to be available via:
    • Horizontal integration of low vision rehabilitation services, for example, to provide comprehensive and person-centered care: establish a strong set of cross-sector alliances/partnerships/multidisciplinary teams to meet the needs of people with various disabilities. These include training to use assistive technology, providing support, facilitating referrals, and access to education, rehabilitation, livelihood, social participation, empowerment, and health elements of community-based rehabilitation.13,17
    • Vertical integration, for example, to facilitate access to services and provide continuity of care: establish/strengthen low vision rehabilitation services at all levels—ideally, integrate these services into existing infrastructure and services, such as state, provincial, and district hospitals, and into community-based services; establish links and referral pathways between levels of low vision rehabilitation services; and support collaboration and communication between all professionals involved in the low vision rehabilitation services process and between workers at different levels of the low vision rehabilitation services process.15
    • Alternative service delivery models, for example, targeted services or care for groups identified to require those at greatest risk;
    • Appropriate services, for example, the use of information obtained from access audits in partnership with local disability groups, to facilitate physical access to services and encourage accessible information provision such as braille and audio.
  • 3. Increase the knowledge base to be able to assist people with disabilities, for example:
    • Include people with disabilities in developing and delivering training and awareness-raising materials.
    • Participate in increasing public awareness and understanding on disability and to reduce the social stigma attached to assistive technology.
    • Share information and liaise with organizations that support people with disabilities.
    • Ensure that both clinical/technical and support staff support and protect the rights and dignity of persons with disabilities and that they are adequately trained in disability, implementing training as required.18
    • Support the inclusion of low vision rehabilitation, theory, and practical into health, education, and rehabilitation training and continuing development curricula of various cadres, to address the shortage of competent people trained to provide low vision rehabilitation services.
      • 4. Participate in advocacy campaigns that urge governments and other organizations interested in improving access to services for people with disabilities and assistive technology to:
    • Acknowledge the rights of people with disabilities to be able to access good quality services and appropriate assistive technology to enhance their functional ability, participation, independence, and quality of life.
    • Substantially improve both quality and coverage/distribution of services for people with disabilities, ensuring that these are available both in urban and across rural areas and can be accessed by the most vulnerable groups.
    • Integrate the provision of services for people with disabilities into the roles of the wider health care team and existing health facilities, also into public health, education, and social systems.
    • Develop national policies and guidelines for services for people with disabilities, also to simplify assistive technology import regulation and reduce import duties and taxes in the national eye health and/or ministry of health strategies.
    • Allocate national health funds to specific services for people with disabilities and to develop/ strengthen partnerships between nongovernmental organizations and government (groups such as the Vision Alliance, can support these advocacy efforts) to support low vision rehabilitation services.
    • Address the wider contextual factors, such as attitudes to disability, the accessibility of the built environment, and the legislation around the provision of information to support the ability of people with a disability to do an activity, participate in a community, and be well.

In conclusion, the issues surrounding access to assistive technology are multiple and complex. Not only does the number of people who could benefit from access exceed the current availability of services, but also the need for assistive technology is escalating. The population is aging, and disabilities due to chronic causes are increasing, as are the requirements for integrated and ongoing care to deal with psychological impact and comorbidities. A number of opportunities that could serve to facilitate access to services and assistive technology are, however, emerging. Concerted advocacy efforts, enriched by the contribution of people with disabilities and health personnel, could facilitate improvements in awareness and access. As advances in innovative technology evolve to meet individual needs and expectations, which enable individuals to engage in activities that in the past would have been impossible, and become more affordable, progress to universal access must surely accelerate. The generation who are becoming increasingly comfortable with obtaining information and interacting with their world through digital technology will no doubt enthusiastically receive and be able to optimally use these advances in technology. Furthermore, concurrent changes in the wider society, such as improving attitudes to disability, new disability-friendly legislation, and improvements in the environment, may serve to increase access and demand for assistive technology through influencing the perception of assistive technology.13 Instead of viewing assistive technology as devices of which to be ashamed, assistive technology might well become sought after as an exciting and desirable product to display as the latest trend to enhance capabilities.

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REFERENCES

1. International Agency for the Prevention of Blindness (IAPB). Low Vision; 2018. Available at: https://www.iapb.org/knowledge/what-is-avoidable-blindness/low-vision/. Accessed May 20, 2018.
2. World Health Organization (WHO). Deafness and Hearing Loss; 2018. Available at: http://www.who.int/mediacentre/factsheets/fs300/en/. Accessed May 20, 2018.
3. World Health Organization (WHO). Hearing Loss Infographic; 2018. Available at: www.who.int/entity/deafness/world-hearing-day/World-Hearing-Day-Infographic-EN.pdf. Accessed May 20, 2018.
4. World Health Organization (WHO). 10 Facts on Disability; 2018. Available at: http://www.who.int/features/factfiles/disability/en/. Accessed May 20, 2018.
5. UNESCO. Education and Disability; 2018. Available at: https://en.unesco.org/themes/inclusion-in-education/disabilities. Accessed May 20, 2018.
6. Chiang PP, O'Connor PM, Le Mesurier RT, et al. A Global Survey of Low Vision Service Provision. Ophthalmic Epidemiol 2011;18:109–21.
7. Humphreys G. Technology Transfer Aids Hearing. Bull World Health Organ 2013;91:471–2.
8. Court H, McLean G, Guthrie B, et al. Visual Impairment Is Associated with Physical and Mental Comorbidities in Older Adults: A Cross-sectional Study. BMC Med 2014;12:181.
9. Ribeiro MV, Hasten-Reiter Júnior HN, Ribeiro EA, et al. Association between Visual Impairment and Depression in the Elderly: A Systematic Review. Arq Bras Oftalmol 2015;78:197–201.
10. Heine C, Browning C. Dual Sensory Loss in Older Adults: A Systematic Review. Gerontologist 2015;55:913–28.
11. One Hundred First United States Congress. Statute—Individuals with Disabilities Education Act (IDEA) 20 U.S.C. 1401 (33)(25); 1990. Available at: idea.ed.gov/part-c/downloads/IDEA-Statute.htm. Accessed May 20, 2018.
12. World Health Organization (WHO). Disability: Assistive Devices and Technology; 2018. Available at: http://www.who.int/disabilities/technology/en/. Accessed May 20, 2018.
13. Ryan B. Models of Low Vision Care: Past, Present and Future. Clin Exp Optom 2014;97:209–13.
14. Binns AM, Bunce C, Dickinson C, et al. How Effective Is Low Vision Service Provision? A Systematic Review. Surv Ophthalmol 2012;57:34–65.
15. Chiang PP, Marella M, Ormsby G, et al. Critical Issues in Implementing Low Vision Care in the Asia-Pacific Region. Indian J Ophthalmol 2012;60:456–9.
16. Leat SJ. A Proposed Model for Integrated Low-vision Rehabilitation Services in Canada. Optom Vis Sci 2016;93:77–84.
17. Bentley SA, Jackson AJ, Johnston AW, et al. Advancing Low Vision Services: A Plan for Australian Optometry. Clin Exp Optom 2014;97:214–20.
18. Chiang PP, Keeffe JE. Improving Access to Low Vision Services. Community Eye Health 2012;25:15.
19. Jose J, Thomas J, Bhakat P, et al. Awareness, Knowledge, and Barriers to Low Vision Services among Eye Care Practitioners. Oman J Ophthalmol 2016;9:37–43.
20. World Health Organization (WHO). International Standards for Vision Rehabilitation: Report of the International Consensus Conference 2015. 2017. Available at: https://www.google.com/search?q=International+Standards+for+Vision+Rehabilitation%3A+Report+of+the+International+Consensus+Conference&ie=utf-8&oe=utf-8&client=firefox-b. Accessed May 20, 2018.
21. Minto H, Awan H. Establishing Low Vision Services at Secondary Level. Community Eye Health 2004;17:5.
22. World Health Organization (WHO). Asia Pacific Regional Low Vision Workshop, Hong Kong, 28–30 May 2001: WHO/PBL/02.87; 2002. Available at: http://www.who.int/iris/handle/10665/67744. Accessed May 20, 2018.
23. Smith EM, Gowran RJ, Mannan H, et al. Enabling Appropriate Personnel Skill-mix for Progressive Realization of Equitable Access to Assistive Technology. Disabil Rehabil Assist Technol 2018;13:445–53.
24. Chiang PP, Xie J, Keeffe JE. Identifying the Critical Success Factors in the Coverage of Low Vision Services Using the Classification Analysis and Regression Tree Methodology. Invest Ophthalmol Vis Sci 2011;52:2790–5.
25. World Health Organization (WHO). Assistive Technology; 2018. Available at: www.who.int/mediacentre/factsheets/assistive-technology/en/. Accessed May 20, 2018.
26. Sturchio JL. The Case of Ivermectin: Lessons and Implications for Improving Access to Care and Treatment in Developing Countries. Community Eye Health 2001;14:22–3.
27. World Health Organization (WHO). Public Health, Innovation, Intellectual Property and Trade: Priority Assistive Products List; 2018. Available at: http://www.who.int/phi/implementation/assistive_technology/EMP_PHI_2016.01/en/. Accessed May 20, 2018.
28. Minto H, Cho J, Hoare P, et al. Global Framework for Low-vision Care: International Agency for Prevention of Blindness (IAPB) Essential List for Low Vision Services. Optom Pract 2017;18:49–56.
29. International Agency for the Prevention of Blindness (IAPB). IAPB Essential List: Low Vision; 2017. Available at: https://iapb.standardlist.org/essential-lists/essential-list-low-vision/. Accessed May 20, 2018.
30. International Agency for the Prevention of Blindness (IAPB). IAPB Standard List; 2018. Available at: https://iapb.standardlist.org. Accessed May 20, 2018.
31. International Agency for the Prevention of Blindness (IAPB); 2018. Low Vision Work Group. Available at: https://www.iapb.org/about-iapb/iapb-work-groups/low-vision-work-group/. Accessed May 20, 2018.
32. The Hong Kong Society for the Blind Vision. Vision. Low Vision Resource Centre 2020;2018. Available at: https://www.hksb.org.hk/en/product/61518/Vision2020LowVisionResourceCentre/. Accessed May 20, 2018.
33. American Academy of Ophthalmology Preferred Practice Pattern Committee. Preferred Practice Pattern Guidelines. Vision Rehabilitation; 2017. Available at: https://www.aao.org/preferred-practice-pattern/vision-rehabilitation-ppp-2017. Accessed May 20, 2018.
34. Wong EY, O'Connor PM, Keeffe JE. Establishing the Service Potential of Secondary Level Low Vision Clinics. Optom Vis Sci 2011;88:823–9.
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