Rapid Assessment of Avoidable Blindness (RAAB)

What is RAAB?

The Rapid Assessment of avoidable blindness (RAAB) is a rapid survey methodology developed at ICEH, and used to complete over 380 surveys of vision impairment and blindness in over 80 countries since 2000.

RAAB is rapid because it uses simplified examination techniques and requires a small sample size (due to only including examination of people aged 50+).

RAAB incorporates a standardised training programme supported by qualified RAAB Trainers, mobile data entry with in-built logic, and automated analysis and report generation. RAAB data are collated and displayed on the RAAB website. 

This page provides an overview of the purpose of RAAB, the current RAAB7 development project, what RAAB is not, and RAAB trainers that you can contact for support. In addition:

• List of qualified RAAB trainers you can contact for support
• Key considerations if you are planning to undertake a RAAB
• Information on the Diabetic Retinopathy (DR) module within RAAB

What is RAAB for?

The main aims of RAAB are:

• to estimate the prevalence and causes of blindness and vision impairment in a given area
• to assess effective cataract surgical coverage and refractive error coverage
• to measure outcome after cataract surgery
• to identify the main barriers to the uptake of cataract surgery

Using sound epidemiological methods, these data are used to design and evaluate eye care programmes in the surveyed area.

RAAB was originally designed for use at the district level but is equally as valuable for reporting national level estimates.

What is the impact of RAAB?

RAAB is integral to ensuring the success of efforts to reduce global eye health:

• RAAB data allows governments and NGOs to plan and evaluate locally-relevant eye health programmes
• RAAB provides much of the data used to estimate global and regional prevalence and causes of vision impairment. RAAB contributed 46% of data for vision impairment and 61% of data for the causes of vision impairment to the latest Global Burden of Disease Study for vision impairment. This data informs the IAPB Vision Atlas and has a direct impact on policy, for instance informing the first United Nations’ resolution on vision
• RAAB generates key data to track progress towards WHO global eye health targets: effective refractive error coverage (eREC) and effective cataractsurgical coverage (eCSC). RAAB data was instrumental in establishing a baseline for the targets (100% of eCSC data sources and 87% of eREC sources were from RAAB)

Learn more about the impact of RAAB through our infographic.

RAAB7: the next generation of RAAB

RAAB has been developed iteratively since the early 2000s. The 7^th generation of RAAB – RAAB7, launched December 2021, is a joint project between ICEH and Peek Vision. RAAB7 fully digitises the RAAB workflow, delivered on the Peek platform.  It further enhances RAAB’s ability to support eye health planning and includes several new features that deliver higher integrity data such as live data monitoring.

In addition, RAAB7 contains new modules developed to maximise the utility of RAAB in eye health planning. An optional disability module (using the Washington Group Short Set Enhanced) has already been developed, and further new modules and inputs related to near vision and presbyopia, health systems data, and health economics are being explored.

What RAAB is not

• RAAB is not a case-finding exercise: it will not provide a list of names and addresses of all people who are blind due to (for example) cataract in an area.
• RAAB is not a detailed vision survey: it provides a reasonably accurate estimate of the prevalence of blindness, and the proportion that is avoidable, in a geographic area. RAAB is not designed to give accurate estimates of the prevalence of specific causes of blindness and does not measure posterior segment disease in detail.
• RAAB focuses on people aged 50 years and above and so it does not give an estimate of childhood blindness, which is better measured through other approaches such as the Key Informant Method.
• RAAB does not provide detailed data on human and financial resources, which are also imperative for eye health planning. However, a concise health systems data collection tool is being developed within the RAAB7 project.

Who should carry out a RAAB survey?

The entire process of carrying out a RAAB survey, from planning to the collection of field data, data analysis and report writing, can be conducted by local staff with the support of a RAAB Trainer. 3-5 data collection teams with transport can cover the usual required sample size in a minimum period of 5-6 weeks, including 1 week of training. The collection of data can be done by local ophthalmologists, or residents in ophthalmology, together with an assistant who does not need to be medically trained. The use of a local guide to introduce the survey team in the community is essential.

Want to carry out your own RAAB survey?

Good planning and organisation are vital for success. Although RAAB has the word “rapid” in its title it is neither easy nor straightforward to undertake. If the RAAB is not undertaken carefully and to a high level of quality then it will give biased results which will not help with planning or evaluation and will have wasted time and money. RAABs therefore need to be planned and undertaken carefully, and must be supported by a qualified RAAB Trainer. Further information on planning for a RAAB is available here. A full list of qualified RAAB trainers by region is available further up this page. You must engage with a qualified RAAB trainer before undertaking a RAAB.

Acknowledgements

Since its inception more than two decades ago, the Rapid Assessment of Avoidable Blindness has received funding support from many donors including ourselves (ICEH), CBM, the Danish International Development Agency (Danida), Fight for Sight, The Fred Hollows Foundation, the Indigo Trust, Orbis, Peek Vision, The Queen Elizabeth Diamond Jubilee Trust, Roche, Sightsavers and the World Health Organization.

RAAB7 was developed in consultation with a steering group made up of representatives from IAPB, the Vision Loss Expert Group (VLEG), the Vision Catalyst Fund and major eye health non-governmental organisations including CBM, The Fred Hollows Foundation and Sightsavers. Dr Hans Limburg, who first developed the RAAB methodology, remains an active member of the steering group, along with several senior RAAB Trainers. The steering group’s valuable input has helped shape RAAB7 to best serve the sector.

Find out more

Contact the RAAB team on enquiries@raab.world for more information.