Elimination of avoidable blindness due to cataract: where do we prioritize and how should we monitor this decade?

Abstract

Background: In the final push toward the elimination of avoidable blindness, cataract occupies a position of eminence for the success of the Right to Sight initiative.

Aims: Review existing situation and assess what monitoring indicators may be useful to chart progress towards attaining the goals of Vision 2020.

Settings and design: Review of published papers from low and middle income countries since 2000.

Materials and methods: Published population-based data on prevalence of cataract blindness/visual impairment were accessed and prevalence of cataract blindness/visual impairment computed, where not reported. Data on prevalence of cataract blindness, cataract surgical coverage at different visual acuity cut offs, surgical outcomes, and prevalence of cataract surgery were analyzed. Scatter plots were used to look at relationships of some variables, with Human Development Index (HDI) rank. Available data on Cataract Surgical Rate (CSR) was plotted against prevalence of cataract surgery reported from surveys.

Results: Worse HDI Ranks were associated with higher prevalence of cataract blindness. Most studies showed that a significant proportion of the blind were covered by surgery, while a fifth showed that a significant proportion, were operated before they went blind. A good visual outcome after surgery was positively correlated with higher surgical coverage. CSR was positively correlated with cataract surgical coverage.

Conclusions: Cataract surgical coverage is increasing in most countries at vision <3/60 and visual outcomes after cataract surgery are improving. Establishing population-based surveillance of cataract surgical need and performance is a strong monitoring tool and will help program planners immensely.

Figure 1

Relationship between prevalence of cataract blindness among 50+ population and Human Development Index Rank

Figure 2

Relationship between Cataract Surgical Coverage (<20/400 person level) and Best Corrected Visual Acuity (≥20/63 in better eye)

Figure 3

Relationship between Human Development Index Rank and Cataract Surgical Coverage (<20/63 better eye - person level)

Figure 4

Relationship between prevalence of cataract surgery (%) and Cataract surgical coverage (<20/400 - person level)

Figure 5

Relationship between prevalence of cataract surgery (%) and reported Cataract Surgical Rate/million population