Refractive error study in young subjects：results from a rural area in Paraguay

AIM：To evaluate the distribution of refractive error in young subjects in a rural area of Paraguay in the context of an international cooperation campaign for the prevention of blindness. METHODS：A sample of 1466 young subjects（ranging from 3 to 22 years old）,with a mean age of 11.21±3.63 years old,were examined to assess their distance visual acuity（VA）and refractive error. The first screening examination performed by trained volunteers,included visual acuity testing,autokeratometry and non-cycloplegic autorefraction. Inclusion criteria for a second complete cycloplegic eye examination by an optometrist were VA 〈20/25（0.10 log MAR or 0.8 decimal）and/or corneal astigmatism ≥1.50 D. RESULTS：An uncorrected distance VA of 0 log MAR（1.0decimal）was found in 89.2% of children. VA 〈20/25 and/or corneal astigmatism ≥1.50 D was found in 3.9% of children（n=57）,with a prevalence of hyperopia of 5.2%（0.2%of the total）in this specific group. Furthermore,myopia（spherical equivalent ≤-0.5 D）was found in 37.7% of the refracted children（0.5% of the total）. The prevalence of refractive astigmatism（cylinder ≤-1.50 D）was 15.8%（0.6% of the total）. Visual impairment（VI）（0.05≤VA≤0.3）was found in 12/114（0.4%）of the refracted eyes. Main causes for VI were refractive error（58%）,retinal problems（17%,2/12）,albinism（17%,2/12）and unknown（8%,1/12）.CONCLUSION：A low prevalence of refractive error has been found in this rural area of Paraguay,with higher prevalence of myopia than of hyperopia.

The prevalence of uncorrected refractive error in urban, suburban, exurban and rural primary school children in Indonesian population

Uncorrected refractive error（URE） is a major health problem among school children. This study was aimed to determine the frequency and patterns of URE across 4 gradients of residential densities（urban, exurban, suburban and rural）. This was a cross-sectional study of school children from 3 districts in Yogyakarta and 1 district near Yogyakarta, Indonesia. The information regarding age, sex, school and school grader were recorded. The Snellen＇s chart was used to measure the visual acuity and to perform the subjective refraction. The district was then divided into urban, suburban, exurban and rural area based on their location and population. In total, 410 school children were included in the analyses（urban=79, exurban=73, suburban=160 and rural=98 school children）. Urban school children revealed the worst visual acuity（P〈0.001） and it was significant when compared with exurban and rural. The proportion of URE among urban, suburban, exurban and rural area were 10.1%, 12.3%, 3.8%, and 1%, respectively, and it was significant when compared to the proportion of ametropia and corrected refractive error across residential densities（P=0.003）. The risk of URE development in urban, suburban, exurban, and rural were 2.218（95%CI： 0.914-5.385）, 3.019（95%CI： 1.266-7.197）, 0.502（95%CI： 0.195-1.293）, and 0.130（95%CI：0.017-0.972）, respectively. Urban school children showed the worst visual acuity. The school children in urban and suburban residential area had 2 and 3 times higher risk of developing the URE.