Changes in prevalence and causes of visual impairment and cataract surgical coverage in Nampula, Mozambique between 2011 and 2018: findings from two cross-sectional surveys

Abstract

<jats:title>Abstract</jats:title> <jats:p>Background Globally, there are few examples of repeated eye health surveys to assess changes in prevalence and causes of visual impairment, and service coverage over time. Two separate, unlinked rapid assessments of avoidable blindness (RAAB) were conducted in Nampula province, Mozambique in 2011 and 2018. This paper reports the observed changes and examines how the trends differ for males and females. Methods Standard RAAB methodology was used in both studies. Two-stage cluster sampling was used to generate random samples of adults aged over 50 years. Participants underwent a simplified visual acuity exam focusing on presenting and pinhole visual acuity (VA), a lens exam and posterior segment exam using a direct ophthalmoscope for all subjects with presenting VA &lt; 6/18. Data were analysed using Stata and logistic regression models were developed to assess changes. Results The 2011 study enrolled 3,050 people and examined 96.9% (2,954 people). The 2018 survey enrolled 4,191 people and examined 95.8% (4,015 people). Age and sex adjusted estimates of blindness decreased from 6.2% in 2011 to 4.5% in 2018 (z=-2.21, p = 0.028), severe visual impairment remained the same (2.6% in 2011 and 2.7% in 2018, z = 0.1, p = 0.9) and moderate visual impairment increased (5.9% in 2011 to 11.0% in 2018, z = 5.78, p &lt; 0.001). Cataract surgical coverage was higher among males in both surveys (13.4% among males vs 7.7% among females in 2011, and 40.0% among males vs 19.4% among females in 2018) and the gender disparity grew between surveys. Conclusions Significant changes were observed in the eye health and service coverage between 2011 and 2018. An increase in the proportion of good visual acuity among operated eyes between the surveys is of note and may correspond with improvements made to the services provided in the province. Further improvements to services are required to improve access for women and people with moderate visual impairment.</jats:p>