ABSTRACT

Purpose

Epidemiological data is essential for planning; however, all-age population-based surveys are resource intensive. Rapid Assessment of Cataract Surgical Services methodology was developed in India in 1995 and subsequently promoted by the World Health Organisation for use worldwide. The commonly used Rapid Assessment of Avoidable Blindness (RAAB) evolved from this in 2005, constraining surveys to populations aged 50 or more based on the report ‘The Epidemiology of Blindness in Nepal’ (SEVA, 1988), where 78.7% of blindness occurred in people aged 50+. The purpose of this study is to examine whether more recent total-population-based surveys continue to find a similar proportion of blindness in the population aged 50+.

Methods

A systematic literature review identified all population-based surveys of blindness published 1996–2017. Data extraction was undertaken by two independent researchers and compared.

Results

The proportions of blindness (presenting visual acuity (PVA) <3/60) and moderate/severe visual impairment (MSVI) (PVA <6/18–3/60) from total population-based surveys in people aged 50+ ranged from 90% (Mali, 1996) to 45.8% (South Korea, 2015); the mean proportions across all surveys were 73.1% (95% CI, 60.4–85.8%) for blindness, and 73.8% (95% CI, 54.8–92.8) for MSVI. No trend over time or association with GDP was identified.

Conclusion

This systematic literature review supports the rationale for constraining surveys to the population aged 50+ as this will greatly reduce sample size but still include a high proportion of total cases of blindness; paucity of total population-based surveys highlights the ongoing need for RAAB in service planning internationally.

中文翻译：

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从基于总人口的失明和视力障碍调查中系统评价 50 岁及以上人口的失明比例

摘要

目的

流行病学数据对于规划至关重要；然而，基于所有年龄人口的调查是资源密集型的。白内障手术服务快速评估方法于 1995 年在印度开发，随后由世界卫生组织推广在全球范围内使用。2005 年，常用的可避免失明快速评估（RAAB）由此演变而来，根据报告“尼泊尔失明流行病学”（SEVA，1988）将调查限制在 50 岁或以上人群，其中 78.7% 的失明发生在50岁以上的人。本研究的目的是检查最近的基于总人口的调查是否继续发现 50 岁以上人口中的失明比例相似。

方法

系统文献回顾确定了 1996-2017 年发表的所有基于人群的失明调查。数据提取由两名独立研究人员进行并进行比较。

结果

在 50 岁以上人群的总人口调查中，失明（表现为视力（PVA）<3/60）和中度/重度视力障碍（MSVI）（PVA <6/18–3/60）的比例范围为 90 %（马里，1996 年）至 45.8%（韩国，2015 年）；在所有调查中，失明的平均比例为 73.1%（95% CI，60.4-85.8%），MSVI 的平均比例为 73.8%（95% CI，54.8-92.8）。没有发现随时间推移的趋势或与 GDP 的关联。

结论

该系统性文献综述支持将调查限制在 50 岁以上人群的基本原理，因为这将大大减少样本量，但仍然包括很高比例的失明病例；总体人口调查的缺乏凸显了 RAAB 在国际服务规划中的持续需求。