The World Report on Vision, 2019, highlights the lack of robust survey data as a key challenge to addressing eye conditions and visual impairment (VI), particularly in sub-Saharan Africa(1). Changing demographics and lifestyles mean that the number of people affected by eye conditions is rapidly increasing, but not necessarily in line with the capacity of the health system or health seeking behaviour(2). Up-to-date population-based survey data is key for planning eye care services and monitoring changes in the epidemiology of eye diseases. Repeated surveys that use the same methodology and measures are also important to track and measure progress of eye care response over time and ensure services remain geared towards the needs of the populations they serve(3, 4).
Key indicators of success for national blindness prevention programmes have been long understood to include prevalence and causes of visual impairment, as well as measures of coverage of services among the population, for example cataract surgical coverage (CSC) which describes the proportion of people who have received cataract surgery, divided by the population in need(1, 4–6). However, more recently, there is a move to examine service coverage beyond a crude measure such as CSC, and to account for the impact of health interventions on health outcomes. These discussions have led to the introduction of a concept of effective coverage of services, defined as the proportion of the population who have accessed the intervention AND have received the maximum possible health gain given the ideal quality, divided by the population in need of the intervention.(7) Of course, debate remains as to how to define quality, however, the general premise of moving beyond crude coverage ratios to a more nuanced representation of service provision is well accepted. Within eye health therefore, suggestions have been made to create the indicators of effective cataract surgical coverage, and effective refractive error coverage, to be used alongside the crude service coverage indicators.(8, 9)
In addition to measuring these indicators in the population as a whole, it is important to understand how such measures differ between different sub-groups, men and women, rich and poor, urban and rural and those with and without disabilities(8, 10, 11). Evidence exists to suggest that health needs and access to health services varies between different population sub-groups but often to different extents in different locations(10, 12, 13).
The Sustainable Development Goal mantra of leaving no one behind, as well as renewed focus from WHO on achieving universal health coverage, mean that political pressure is greater than ever for governments to demonstrate that they are including all members of society in all they do, including health service provision. Population based surveys, including those focused on visual impairment, need to incorporate measures of equity, to ensure that results can be examined by different population sub-groups (1, 8, 10, 14).
Visual Impairment In Mozambique
No national blindness study has ever been conducted in Mozambique although several sub-national level studies have been undertaken that focus on specific population groups or ocular conditions. Between 2012 and 2015, 96 surveys were conducted to map trachoma in 137 districts across the country including both trichiasis among people aged 15 years and above, and trachomatous inflammation–follicular among children aged 1–9 years(15). A Rapid Assessment of Refractive Error, Presbyopia, and Visual Impairment and Associated Quality of Life among people aged 15–50 years was conducted in Nampula province in 2015(16). Rapid assessments of avoidable blindness (RAAB) have been conducted among people aged over 50 years in Nampula province in 2011, Sofala province in 2012 and Inhambane province in 2016(17–19).
The 2011 RAAB in Nampula identified high prevalence of presenting bilateral blindness (6.2%), with cataract as the major cause (73.0%). Coverage of cataract services were low (10.3%), with women particularly disadvantaged as compared with men (7.7% vs 12.8%). Importantly, visual acuity among operated people was poor, which, although not directly linked with surgical provision, can be considered a crude indicator that surgery was not providing the ‘maximum possible health gain’ for patients.
Nampula Eye Care Programme, 2011-2018
Following the dissemination of findings, The Nampula Eye Care Programme, delivered in partnership between The Ministry of Health and international non-governmental organisation (NGO) Sightsavers, prioritised activities to increase coverage with cataract services and improve visual outcomes of surgery by: introducing optical biometry and a keratometer in the main tertiary hospital and through outreaches in the district hospitals; training and deploying ophthalmic technicians to primary and secondary health facilities throughout the province; strengthening the community outreach programme to improve community education and increase screening services; introducing one week follow-up to deal with immediate complications; and introducing patient transport for surgical services. More recently, since 2016, the partnership has sought to improve the gender focus of the programme and has: increased the proportion of community health workers trained who are female; prioritised women for screening and treatment; sensitised staff to the additional and specific needs for both females and people living with disabilities; and introduced a standardised cataract monitoring tool to identify any poor results and implement improvements(20, 21).
In 2018, the Nampula eye care programme conducted a second RAAB in Nampula province to measure changes since the 2011 study and realign programme activities according to the updated data. The objective of this paper is to report how the prevalence and causes of VI, and crude and effective coverage of cataract services has changed between RAABs conducted in Nampula province in 2011 and 2018. We also sought to understand how the situation differed for men and women between 2011 and 2018.