Discussion
In 2019, 1787 cataract operations were conducted in Imo state and just over half were performed on women. The overall CSR was estimated to be 330/million, which is less than a third of the recent CSRs in other states in Nigeria,13 15 and lower than the target for Africa of 1000 which was set more than 20 years ago.11 Other countries in SSA have reported higher CSRs, for example, 1016 in Mali and 1993 in The Gambia, or lower CSRs, for example, 163 in the Republic of Congo and 197 in Uganda.12 In our study, almost one in eight patients were initially identified during outreach, without which the CSR would only be 288/million/year. Our results indicate that the CSR in Imo State is low and needs to be increased and highlights that outreach may play an important role, particularly for older women.
The CSR in women (347/million) was 10% higher than in men (315/million). This is the first study in Nigeria to report a higher CSR in women than men. Several other studies report cataract surgical coverage (CSC), a population-based indicator of access to surgery, disaggregated by gender,20–23 and studies from Kenya24 and Argentina25 report higher CSCs in women. In contrast, the Nigerian national blindness survey showed a higher CSC in men.5 In a review of 20 Rapid Assessment of Avoidable Blindness surveys, the CSC was lower in women in half of the countries.26 The higher CSR among women in our study may reflect the higher prevalence of cataract blindness in women than men. However, the sex difference disappears when patients accessing services via outreach are excluded, highlighting the importance of this approach for elderly women in this setting. Studies on outreach in Nigeria have inconsistent findings in relation to the proportion of men and women identified with operable cataract and the proportion subsequently undergoing surgery. Differences may be explained by the timing and location of the outreach, and whether transport to base hospitals and subsidised surgery are offered.27–29
To overcome gender inequity in cataract blindness in Nigeria, two-thirds of cataract surgery would need to be undertaken on women,5 but in our study, just over half the surgery was on women. In many LMICs, women are less likely to undergo cataract surgery due to socioeconomic and cultural barriers they face, for example, less access to funds, fear of surgery, fatalistic beliefs, lack of an escort and low levels of education and agency.5 16 Strategies to increase CSR include targeted health promotion for elderly persons or cataract detection at primary healthcare facilities. Operational research and intervention science research are needed to identify interventions which increase access, as there is limited evidence of what works well and for whom in LMICs.19
An unexpected finding was that males who underwent cataract surgery were significantly older than women which does not reflect the age structure in Nigeria.30 Women live longer and are at greater risk of becoming visually impaired from cataract,2 31 hence, the expectation is that women with operable cataract would be older than men. A plausible explanation for our findings is that older women with cataracts are not accessing eye care services. However, age data were not available for 101 patients. If elderly women were less likely to know or reveal their age than men, this would bias the findings. A limitation of the study was that data were not collected on whether the outreach services provided transport to the base hospital, or whether the costs of surgery were lower for patients identified during outreach as both are key factors in accessing care.16 32 33
Triangulating these findings suggests limited access to cataract surgical services, particularly by elderly women. A coordinated, evidence-based approach is necessary to address this as well as gender inequity in cataract services. This could include engaging communities to identify workable solutions to barriers to accessing cataract surgery, particularly among poor, elderly women. Strategies could include outreach targeting elderly women, eye health advocacy, health insurance which target women’s groups, providing community escorts and scaling up primary eye care. Concerning the latter, the Ministry of Health in Nigeria has recently included the WHO AFRO primary eye care training package in primary healthcare workers’ curricula. It is expected that this initiative will improve access to eye care for marginalised populations, particularly women and people living in rural and underserved urban areas.34
The most common procedure for cataract extraction was manual SICS (MSICS) with intraocular lens insertion. Phacoemulsification, which is as effective as MSICS, is more expensive, which may explain why more men than women underwent this procedure.
In our study, a lack of human resources was the main reason why almost half (5/11) of the facilities in Imo State licensed to perform cataract were not doing so. Human resources for eye health (HReH) are essential for eye health service delivery.35 A review of HReH in sub-Saharan Africa found that few countries achieved the suggested targets for ophthalmologists, ophthalmic nurses, optometrists/refractionists and clinical officers.36 37 To improve access to cataract surgery in Imo state, there is a need to address the challenges faced by the five ophthalmic centres not providing cataract services, and to increase the capacity of those currently doing so. The recently launched National Eye Health Policy (NEHP) aims to standardise and equip one secondary level eye unit per million population, including high output, high-quality cataract surgery and to develop competent and capable eye health teams and eye health managers to manage common eye diseases, particularly cataract.38 If appropriately implemented, the NEHP may address the supply-side challenges of eye health in Nigeria.
The findings of this study should be interpreted with caution as it does not include people who may have accessed cataract surgery in neighbouring states or elsewhere. Patients who live in other states may also have been included. The latter is unlikely, as visually impaired patients are likely to access services near where they live. In addition, all the outreach in the state was led by centres within the state. A more representative metric would be CSC from a population-based survey.
A strength of this study is that all cataract surgeries performed in all the active ophthalmic centres were included, and to the authors’ knowledge is the first study in Africa to report CSR by sex. A limitation is that the hospitals did not all record the data required and some data were missing, such as age. Another factor to consider is that the CSR indicator was developed to assess the surgical output of facilities and does not take into account whether one or both eyes of patients are operated on during the same year, that is, CSR is not a person-level indicator. In this study, if more men than women had surgery on both eyes in 2019, sex differences at the person level would increase the sex differences.
