Introduction

In the late 1990s, when Vision 2020: the Right to Sight was being formed, refractive error was not on the blindness prevention agenda. The agenda was based on the assumption that everyone had access to refractive care, so only eye diseases such as glaucoma, trachoma and age-related macular degeneration could cause ‘real’ vision impairment. World Health Organization (WHO) definitions reinforced the assumption by defining vision impairment in terms of best-corrected visual acuity rather than ‘habitual’ or ‘presenting’ vision. The number of people with vision impairment from uncorrected refractive error (URE) was unknown and essentially ignored. A decade later, we know the massive size of the URE problem, and many of the economic, social, personal and development implications it has. URE is now a priority area for Vision 2020 and viable strategies for solving the problem have been identified, defined and evaluated. The key to the second decade of Vision 2020 is scale-up - how can strategies be rolled out to assist the vast number of people who cannot currently access refractive care including spectacles.

Defining the scale of the problem

A series of epidemiological studies published in the late 1990s, including the Andhra Pradesh Eye Disease Study, the Melbourne Vision Impairment Project and the Refractive Error Studies of Children, comprehensively disproved the assumption that everyone could access refractive care [1, 2, 3]. Resnikoff et al (2008) analysed the mounting regional evidence to define the magnitude of the global problem: an estimated 153 million people were vision impaired (visual acuity worse than 6/18 in the better eye), including 8 million who were blind (visual acuity worse than 3/60 in the better eye), because they were unable to access adequate refractive care [4]. This was almost as many as the 161 million people with vision impairment from cataract and all eye disease put together [5].

Although Resnikoff et al (2008) made URE the biggest single cause of vision impairment, their estimate only included vision impairment from distance URE. The issue of near vision impairment from uncorrected presbyopia was highlighted in the same year by Holden et al (2008), who estimated there were 1.04 billion people with presbyopia in the world and that 517 million of them were uncorrected or under-corrected to an extent that caused near vision impairment [6]. In combination, these papers suggest there are 670 million additional cases requiring distance and/or near refractive care including spectacle provision than currently access it. Distance and near URE is now recognised as the major cause of vision impairment and a significant cause of blindness.

Key links between URE and community development

The first decade of Vision 2020 has also seen several important pieces of evidence defining the importance of URE to community and international development. The Millennium Development Goals (MDGs) have become the embodiment of international development efforts during this decade. The MDGs are a rights-based development approach focusing on achieving specific indicators for poverty reduction, equity, sustainability and basic health care by 2015 [7]. Presentations at the World Congress on Refractive Error in 2010 argued strongly that vision, and URE specifically, has important roles in most if not all eight MDGs. The two most essential links with the clearest evidence are to MDGs 1 and 2.

MDG 1 is to halve the proportion of people earning less than $1 per day and halve the proportion of people who suffer from hunger. Smith et al (2009) provided clear evidence of the role of refractive care in this MDG, with their estimate that I$269 billion is lost annually from the global economy just because people are unable to access refractive care including spectacles. The estimate was for distance URE only - the lost productivity from the 517 million cases of vision impairment from uncorrected presbyopia is still unknown. However, given the number of people involved and some preliminary evidence that quality of life may be more sensitive to near VI than distance VI, the economic cost of uncorrected presbyopia is also likely to be significant [8]. Enabling economic productivity via correcting vision impairment from URE will contribute significantly to ending poverty and fulfilling MDG 1.

MDG 2 is to achieve universal primary education. Roch-Levecq et al (2008) provide the clearest causative evidence linking URE with learning outcomes. In a controlled, masked study, they measured changes in cognitive abilities and visual information processing (visual-motor integration skills) directly attributable to correction of refractive error. Enabling educational outcomes [9] via correcting URE in children contributes significantly to education access and fulfilling MDG 2.

Establishing viable solutions to the problem of URE

It seems so simple to refract, choose between spectacles, contact lenses and refractive surgery, and deliver. But the magnitude of the problem demonstrates that too often this process fails at one point or another: inadequate case identification, human resources, infrastructure, or supply chains. The refractive error industry has needed to learn new public health, negotiation and organising skills to tackle the problem.

The development of the WHO’s Refractive Error Working Group in 2000 was an important step toward recognising URE as a blindness prevention issue, stimulating research in many countries around the world, and introducing priorities for vision services and spectacle correction into National VISION 2020 programmes [10].The Durban Declaration on Refractive Error and Service Development summarised the aspirations of the inaugural World Congress on Refractive Error and Service Development in 2007 in South Africa [11].The Refractive Error Programme Committee of the International Agency for the Prevention of Blindness (IAPB) followed with a comprehensive Strategy for the Elimination of Vision Impairment from Uncorrected Refractive Error in 2009 [12].In combination, the WHO work, the Durban Declaration and the IAPB refractive error strategy provide public health leadership for overcoming the global burden of avoidable blindness from URE.

The LV Prasad Eye Institute (LVPEI) in India has successfully presented a large scale, not-for-profit system for delivery of vision care to those in need. The key element in the delivery of refractive services is the Vision Centre, a small facility with a trained Vision Technician or optometrist to deliver eye care to 50,000 people. Eye care delivered at Vision Centres includes primary eye care, refraction, dispensing of spectacles, detection and referral of sight-threatening conditions, as well as spectacle-making facilities in every fifth Vision Centre. Vision Centres have been adopted as a method to decentralise refractive care and eye disease detection in communities throughout Africa, Oceania, Asia and the Americas. Vision Centres can be easily and rapidly established and supported by Government, NGOs, communities and philanthropists, provided human resource development and supply of consumables keeps pace. They should be integrated within other district health and National health priorities.

Key Challenges for the second decade of Vision 2020

The first challenge is the massive scale-up needed to extend delivery of quality eye examinations and spectacles to the hundreds of millions of people who are currently excluded. Strategies, such as Vision Centres and others described in IAPB’s Strategy for the Elimination of Vision Impairment from Uncorrected Refractive Error, can solve the refractive error problem and achieve major public health benefits, not only in correcting refractive error but in preventing blinding diseases by detection and referral. Scaling up the number and quality of eye care personnel is crucial, but it is just as important to develop systems which will effectively compensate and create career paths for the personnel involved in serving remote and underserved communities. LVPEI’s School of Optometry, established through industry sponsorship to train both Vision Technicians over a year and optometrists over four years, provides a successful human resource development example. Other examples are the partnerships between IAPB partners, governments and education institutions that have led to the establishment of Schools of Optometry in Malawi and Mozambique, which provide training for both optometric technicians (two years’training) and optometrists (four years) in a modular approach.

The second challenge is that the magnitude of the URE problem will dramatically worsen unless we act, or may only be held steady by modest grow in refractive care delivery. We need to plan not just to fix the magnitude of the problem today (670 million cases), but to counteract two very substantial exacerbating factors - the global myopia epidemic and the ageing of the world’s population. The prevalence of myopia is growing rapidly, for example reaching 42% (up from 25% in 1972) in the USA, and 81% (up from 64% in 1983) in Taiwanese 15 year olds [13, 14]. Myopia prevalence rates well above 60% are common in teenage children in urban areas of East Asia. The number of people with presbyopia will also rise, due to the aging population. It is estimated that there will be 1.4 billion people with presbyopia in the world by 2020 (up from 1.0 billion in 2007), and 710 million without adequate correction of presbyopia in the world by 2020 (up from 517 million in 2007) without intervention to make spectacles more accessible [15].

The third challenge is resource mobilization. IAPB established a partnership between IAPB, the International Centre for Eyecare Education (ICEE) and the World Council of Optometry (WCO) to create Optometry Giving Sight (OGS). OGS’s mission is to raise funds from optometrists in the developed world to support refractive error programmes and training programmes in the developing world. This is considerably accelerating worldwide recognition, by optometrists and the optical industry, of the need to support public health programmes in refractive error. Partnerships are one way of establishing sustainable programmes. An example of this is ICEE’s programme with the KwaZulu Natal government in South Africa. Other examples include the Standard Chartered Bank’s initiative “Seeing is Believing” and Optometry Giving Sight’s “Vision for Africa” programmes. Such programmes not only establish a local service provision system, but also help to expand and develop the LVPEI Vision Centre model so that it can be implemented in communities in need all over the world in public, private (NGO) and public-private mode.

The fourth challenge is establishing the “supply chain” for optical products. Government policies should encourage the development of local optical industries, procurement of spectacle frames and lenses, and importation without crippling duties on low-cost imported lenses and frames where they are not readily available in the country. Establishment of effective and affordable spectacle supplies in countries currently lacking such supplies, paired with quality human resource and service development, provides sustainable business opportunities across NGO, private and Government sectors.

Conclusion

Ten years into Vision 2020, URE is recognised as the leading cause of vision impairment with important economic, social, personal and development implications. Some key partnerships and strategies are established, but massive expansion and scale-up is required in the second decade if the goals of Vision 2020 are to be realised. Refractive care, combining a quality eye exam and provision of spectacles, should be available at the community level. Development of local optical industries should be encouraged, or the importation of low-cost spectacles facilitated when necessary.