Refractive error and ocular components among schoolchildren in Campinas, Brazil

Abstract

 

Purpose

 

To describe the refractive error and ocular components distribution using a optical reflectometer among schoolchildren in Campinas, Brazil

 

Methods

 

This cross-sectional study was carry out in 2012. At the 2010 census, the population of Campinas, Brazil was 1080113. Of these, 180560 were in the age range of the study; including 126392 (70%) who attended public schools. Four groups of students (total of 1100 individuals) were randomly selected to obtain a representative sample from public schools. They were of the 1st (5-7 years-old), 5th (9-11 years-old), 9th (13-15 years-old), and 12th (16-18 years-old) levels of the Brazilian educational system. The protocol for data collection included measurement of logMAR monocular distance best-corrected visual acuity and cycloplegic autorefraction (Topcon AR-8900). The representative value from the autorefractor was used to calculate spherical equivalent refraction (SER = sphere + cylinder/2). Myopia was defined as a SER ≤ −0.50 D, hyperopia as SER ≥ +2.00 D, emmetropia as -0.50 ≤ SER ≤ +2.00, and refractive astigmatism as ≥1.00 D. The Lenstar LS900 was used for all the measurements of ocular biometry. The measurements were central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), axial length (AL), lens power (LP), keratometry (corneal curvature), pupillometry (in ambient light condition of ± 500 lux), and white-to-white Distance (horizontal iris width). Lens power was calculated with an theoretic intraocular lens calculation formula (Haigis). It was adopt the results of the intraocular lens Acrysof MA60AT. It was choose the intraocular lens power that was more close to the cycloplegic refraction of the student. Data was analysed using the right eye.

 

Results

 

Of the 1100 students invited to participate in the study, overall participation was 70.7% (parental consent was obtained from 778 students). The mean age of the students was 11 SD 4 years (5 to 18 years - median 10), and 440 (56.55%) were girls. The gender distributions were similar between the age groups. Tables 1 describe the distribution according refractive errors and table 2 according the ocular components. The mean spherical equivalent was +0.72 SD 1.19 D (-5.50 to +8.25 D).

 

Conclusions

 

This paper presented a population-based data describing the prevalence of cycloplegic measures of refractive errors and ocular components distribution among schoolchildren in Campinas, Brazil.

 

 

 

Keywords: 605 myopia • 676 refraction • 677 refractive error development