International Centre for Advancement of Rural Eye care, L V Prasad Eye Institute, Hyderabad, India.
BMC Ophthalmol. 2011 Sep 19;11:26. doi: 10.1186/1471-2415-11-26.
Reliable data are a pre-requisite for planning eye care services. Though conventional cross sectional studies provide reliable information, they are resource intensive. A novel rapid assessment method was used to investigate the prevalence and causes of visual impairment and presbyopia in subjects aged 40 years and older. This paper describes the detailed methodology and study procedures of Rapid Assessment of Visual Impairment (RAVI) project.
A population-based cross-sectional study was conducted using cluster random sampling in the coastal region of Prakasam district of Andhra Pradesh in India, predominantly inhabited by fishing communities. Unaided, aided and pinhole visual acuity (VA) was assessed using a Snellen chart at a distance of 6 meters. The VA was re-assessed using a pinhole, if VA was < 6/12 in either eye. Near vision was assessed using N notation chart binocularly. Visual impairment was defined as presenting VA < 6/18 in the better eye. Presbyopia is defined as binocular near vision worse than N8 in subjects with binocular distance VA of 6/18 or better.
The data collection was completed in <12 weeks using two teams each consisting of one paramedical ophthalmic personnel and two community eye health workers. The prevalence of visual impairment was 30% (95% CI, 27.6-32.2). This included 111 (7.1%; 95% CI, 5.8-8.4) individuals with blindness. Cataract was the leading cause of visual impairment followed by uncorrected refractive errors. The prevalence of blindness according to WHO definition (presenting VA < 3/60 in the better eye) was 2.7% (95% CI, 1.9-3.5).
There is a high prevalence of visual impairment in marine fishing communities in Prakasam district in India. The data from this rapid assessment survey can now be used as a baseline to start eye care services in this region. The rapid assessment methodology (RAVI) reported in this paper is robust, quick and has the potential to be replicated in other areas.
可靠的数据是规划眼科保健服务的前提。尽管传统的横断面研究提供了可靠的信息，但它们需要大量资源。一种新的快速评估方法被用于调查 40 岁及以上人群中视力障碍和老视的患病率和原因。本文详细描述了快速评估视力障碍（RAVI）项目的方法学和研究程序。
在印度安得拉邦普拉卡萨姆区沿海地区进行了一项基于人群的横断面研究，采用聚类随机抽样，该地区主要居住着渔民社区。在 6 米的距离处使用 Snellen 图表评估未矫正、矫正和针孔视力（VA）。如果双眼视力均低于 6/12，则使用针孔再次评估 VA。双眼使用 N 标记图表评估近视力。视力障碍定义为较好眼的 VA 低于 6/18。老视定义为双眼远视力为 6/18 或更好，而双眼近视力差于 N8。
使用两个团队，每个团队由一名辅助医学眼科人员和两名社区眼保健工作者组成，在不到 12 周的时间内完成了数据收集。视力障碍的患病率为 30%（95%CI，27.6-32.2）。这包括 111 名（7.1%；95%CI，5.8-8.4）失明患者。视力障碍的主要原因是白内障，其次是未矫正的屈光不正。根据世界卫生组织的定义（较好眼的 VA 低于 3/60），失明的患病率为 2.7%（95%CI，1.9-3.5）。
印度普拉卡萨姆区海洋渔民社区视力障碍的患病率较高。本快速评估调查的数据现在可用作该地区开展眼科保健服务的基线。本文报告的快速评估方法（RAVI）稳健、快速，并且有可能在其他地区复制。
