Prevalence of color vision deficiency and its correlation with amblyopia and refractive errors among primary school children

Abstract

Purpose:To determine the prevalence of color vision deficiency (CVD) and its correlation with amblyopia and refractive errors among primary school children.Methods:In this population-based cross-sectional study, 2160 children were selected from 36 primary schools; 60 students were from each school (10 students in each grade), with equal sex distribution. A complete eye examination including refraction using a photorefractometer, determination of visual acuity (VA) and color vision using a Yang vision tester, and evaluation of ocular media opacity using a direct ophthalmoscope was performed. Children who could not answer at least 4 plates of the Ishihara color test were considered as color vision deficient subjects. Amblyopia was determined if pinhole VA was worse than 0.3 LogMAR (equal to 20/40).Results:The prevalence of CVD was 2.2% (95% CI: 1.5% to 3%) which was higher in male subjects (37 [3.5%] boys vs. 11 [1.0%] girls, P < 0.001). Mean VA was lower among students with CVD as compared to normal color vision children (P = 0.035) and amblyopia was observed in 8.3% (95% CI: 0.2% to 16.4%) of patients with CVD versus 2.1% (95% CI: 1.5% to 2.08%) of children with normal color vision perception (P = 0.005). A statistically significant correlation between lower VA and CVD was observed (P = 0.023).Conclusion:Although CVD was correlated with lower VA and amblyopia, there was no relationship between CVD and the type of amblyopia, refractive error, anisometropia or strabismus.

The prevalence of amblyopia in Iran: A systematic review

“… 34 2011 Tehran 3519 5–86 years 3.69 Multistage (clustering & stratification) 19 Rajavi et al. 35 2015 Tehran 2160 Schoolchilderen (Primary) 2.1 Random cluster sampling 20 Rajavi et al. 36 2015 Tehran 2410 7–12 years 2.3 Random sampling 21 Faghihi et al.…”

“…The main target group in six articles were children up to six years old, 22 , 23 , 25 , 38 , 41 , 42 , 43 and in 20 articles, the subjects aged from 6 to 22 years old. 14 , 18 , 19 , 20 , 21 , 24 , 26 , 27 , 28 , 30 , 32 , 33 , 35 , 36 , 44 , 45 , 46 , 47 , 48 , 49 In two articles, the elderly age group was also included. 29 , 34 In most cases, cluster sampling was done, 14 , 18 , 19 , 20 , 21 , 22 , 26 , 30 , 31 , 32 , 33 , 35 , 37 , 46 and in others, random sampling had been used.…”

“… 12 , 13 , 14 , 15 , 16 , 17 Several studies in different regions of Iran have also reported the prevalence of amblyopia. 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37…”

Prevalence of Color Blindness among Students of Secondary Schools in Shahrekord

“…This test is a global and reliable test for this disease. 9 The light conditions of the test should be similar to the daylight, and therefore the MacBeth light bulb can be used, which is about 100-650 LUX. Alternatives such as a fluorescent bulb of more than 5000 k or Kodak Watten 78aa number with a 100-watt bulb can be utilized because this light bulb is very expensive.…”

“…Statistically, significant differences are reported in this regard, which can be due to differences in races, instruments of examination, and researchers' interpretations of the disease. 8,9 The diagnosis of this disease during schooling is essential for taking the necessary actions for the future life of adolescents. In this respect, interventions can be performed to improve the living conditions and even the type of occupation of these patients so as to be able to prevent some health and financial damage and behavioral abnormalities and ultimately promote the health of the patients and the community.…”