Prevalence of color vision deficiency among Chinese college students and their quality of life

AIM:To investigate the prevalence of color vision deficiency(CVD)among college students and their quality of life(QoL)in a Chinese college.METHODS:This cross-sectional study was performed in Sichuan University in Chengdu,China.The questionnaire containing participants’demographic data,as well as CVD related QoL was distributed to students who were screened as CVD[by Color Vision Examination Plates(Version 6)]in 2022 freshman entrance examination.Color blindness QoL(CBQoL)and utility analysis were used to evaluate the QoL of CVD students.RESULTS:There were 381 of 17303(2.20%)students screened as CVD,including 368(4.11%)males and 13(0.16%)females.A total of 317 students completed the questionnaire,the response rate was 83.20%.Only 166 participants(52.3%)knew they have CVD before the physical examination for college entrance examination,while a total of 145 participants(45.74%)hoped to be diagnosed earlier.The medians of CBQoL score and utility were 5.85(range 2.2-6)and 1(range 0-1),respectively.The proportions of students whose QoL is affected by CVD were 67.63%(211/312)and 42.27%(134/317)measured by CBQoL and utility analysis respectively.CONCLUSION:The prevalence of CVD in males is much higher than that in females.The time when CVD students first became aware of their CVD is relatively late.The QoL of the study population is quite high,while a large proportion of students’QoL are affected by CVD.It is suggested that as a congenital defect,CVD screening in China should be earlier,and appropriate guidance and support are needed for CVD patients to help them better adapt to life,study,and work.

Prevalence and gene frequency of color vision impairments among children of six populations from North Indian region

X-linked redegreen color blindness is the most widespread form of vision impairment.The study aimed to determine the prevalence and gene frequencies of redegreen color vision impairments among children of six different human populations of Jammu province.A total of 1028 healthy subjects(6e15 years of age)were selected from five Muslim populations and the color vision impairments were determined using the Ishihara’s test of color deficiency.The gene frequency was calculated using HardyeWeinberg equilibrium method.The prevalence of color vision deficiency(CVD)ranged from 5.26%to 11.36%among males and 0.00%e3.03%among females of six different populations.The gender based differences in the frequency of CVD was found to be statistically significant(p<0.0001),with a higher prevalence among male(7.52%)as compared to female(0.83%)children.We observed high frequency of deutan as compared to protan defects.The incidences of deuteranomaly(5.68%)and deuteranopia(2.27%)were higher among male children of Syed population while the frequencies of protanomaly(1.94%),protanopia(1.28%)and achromacy(2.27%)were the highest among male subjects of Khan,Malik and Syed populations,respectively.The allele and genotype frequencies showed cogent differences among six populations.The population based assessment of CVDs help patients to follow adaptive strategies that could minimize the risks of the disease.

An objective method for color vision deficiencies measurement based on visual evoked potential

The equi-luminance of color stimulus in normal subjects is characterized by L-cone and M-cone activation in retina. For the protanopes and deuternopes, only the activations of one relevant remaining cone type should be considered. The equi-luminance turning curve was established for the recorded visual evoked potentials (VEPs) of the luminance changes of the red and green color stimulus, and the position of the equi-luminance was used to define the kind and degree of color vision deficiencies. In the test of 47 volunteers we got the VEP traces and the equi-luminance turning curves, which was in accordance with the judgment by the pseudoisochromatic plate used in clinic. The method fulfills the objective and quantitative requirements in color vision deficiencies test.