Prevalence and causes of blindness in children in Vietnam.

OBJECTIVE: To estimate the prevalence of blindness in children in Vietnam and to assess the major causes. DESIGN: A population-based study sampled children from 16 provinces across Vietnam. The second study examined children attending all blind schools in Vietnam. PARTICIPANTS: In 16 provinces, 28 800 children aged 0-15 were sampled. In 28 blind schools, 569 children aged 0-15 were examined. INTERVENTION: In children not seeing well according to the parents, presenting visual acuity (PVA) was assessed. If PVA was <3/60 in one or both eyes, the child was examined by an ophthalmologist. All children in blind schools were examined by a pediatric ophthalmologist. MAIN OUTCOME MEASURES: Blindness was defined as PVA <3/60 in the better eye. Causes of visual loss were classified using the World Health Organization classification. RESULTS: In the population-based study, 22 children had a PVA <3/60 in the better eye, a prevalence of 7.6/10 000 children (95% confidence interval [CI], 4.9-11.8/10 000). Fourteen children had a pinhole visual acuity <3/60 in the better eye, a prevalence of 4.9/10 000 (95% CI, 2.8-8.4/10 000). An estimated 16 400 (95% CI, 10 500-25 300), children were blind from all causes, with 36.4% from uncorrected refractive errors. In the blind schools, 411 children had a PVA <3/60 in the better eye and 55.5% were male. Conditions of the retina (24.6%) and cornea (24.0%) predominated. Retinopathy of prematurity (ROP) caused blindness in 32.6% of children younger than 10 years, but in only 6% of older children. The converse was true for corneal scarring and phthisis (14.0% and 27.3%, respectively). All other causes were similar between age groups (53.5% and 66.7%, respectively). More than half of all causes were avoidable. CONCLUSIONS: Vietnam is developing very rapidly, and this is impacting health indices. The mortality rate of those younger than 5 years declined from 65/100 live births in 1980 to 14/100 in 2008. The findings of this study show these changes, because the childhood blindness prevalence was relatively low, and the causes show improved control of measles and vitamin A deficiency, as well as increased services for premature babies. Eye care services for children should now focus on refractive errors, cataract, and control of ROP.

Trachoma in Viet Nam: results of 11 surveillance surveys conducted with the Global Trachoma Mapping Project.

PURPOSE: Following interventions against trachoma in Viet Nam, impact surveys conducted in 2003-2011 suggested that trachoma was no longer a public health problem. In 2014, we undertook surveillance surveys to estimate prevalence of trachomatous inflammation-follicular (TF) and trichiasis. METHODS: A population-based prevalence survey was undertaken in 11 evaluation units (EUs) encompassing 24 districts, using Global Trachoma Mapping Project methods. A two-stage cluster sampling design was used in each EU, whereby 20 clusters and 60 children per cluster were sampled. Consenting eligible participants (children aged 1-9 years and adults aged ≥50 years) were examined for trachoma. RESULTS: A total of 9391 households were surveyed, and 20,185 participants (98.8% of those enumerated) were examined for trachoma. EU-level TF prevalence in 1-9-year-olds ranged from 0% to 1.6%. In one cluster (in Hà Giang Province), the percentage of children with TF was 10.3%. The overall pattern of cluster-level percentages of children with TF, however, was consistent with an exponential distribution, which would be consistent with trachoma disappearing. Among people aged ≥50 years, prevalence of trichiasis by EU ranged from 0% to 0.75%; these estimates are equivalent to 0-0.13% in all ages. The prevalence of trichiasis unknown to the health system among people aged ≥50 years, by EU, ranged from 0% to 0.17%, which is equivalent to 0-0.03% in all ages. CONCLUSION: Findings suggest that trachoma is no longer a public health problem in any of the 11 EUs surveyed. However, given the high proportion of children with TF in one cluster in Hà Giang Province, further investigations will be undertaken.

Control of vitamin A deficiency in Vietnam: achievements and future orientation.

Vitamin A deficiency is one of the major nutritional deficiencies in Vietnam. The first survey, conducted in 1985-1988 showed that the prevalence of severe xerophthalmia was seven times higher than the cutoff point established by the World Health Organization (WHO) to define vitamin A deficiency as a public health problem. The result of this survey strongly convinced the government to launch a program to control vitamin A deficiency, which started in 1988. The program strategies included nutrition education, universal distribution of high-dose vitamin A capsules to children aged 6 to 36 months in combination with national immunization days, and promotion of production and consumption of vitamin A-rich foods at the family level. The implementation network was set up based on the existing preventive health structure at all administrative levels. Organizations such as the women's union and other social sectors have participated actively in the program. Surveys conducted in 1994 and 1998 showed that the prevalence of clinical xerophthalmia was significantly lower than that identified in the baseline survey and below the WHO criteria for a public health problem. The achievements of our program have demonstrated that an effective vitamin A supplementation program can be implemented successfully by the preventive health network with active community participation. In the coming years, it will be important for our program to develop approaches other than vitamin A supplementation in order to maintain the past achievements.