Screening for congenital colour vision defects. A comparison between the Ohkuma and Ishihara plates

The Change in Color Vision with Normal Aging Evaluated on Standard Pseudoisochromatic Plates Part-3

Purpose: To evaluate the influence of aging on color vision in a large normal population using Standard Pseudoisochromatic Plates part-3 (SPP-3), which is a pseudoisochromatic plate test used to detect congenital or acquired color vision deficiency (CVD).Materials and methods: We retrospectively reviewed SPP-3 test results of 23,565 normal eyes of 23,565 subjects (women: 12,035; men: 11,530), who were examined between July 1993 and December 2010. The subjects had a mean age of 46.9 ± 18.5 years, ranging from 5 to 89 years, and they were evaluated following categorization into age groups with five-year increments. Subjects whose best-corrected visual acuity (BCVA) was 20/20 or better, with no history of ocular diseases, were included. Subjects with congenital CVD were excluded.Results: We found a negative correlation between age and the total number of correct answers in SPP-3 (Spearman's correlation coefficient, r = -0.5743; p < .0001). The total number of correct answers was the highest in subjects aged 10-14, 15-19, and 20-24 years (17.2 ± 0.9 [mean ±SD]). The total number of correct answers of these groups had significant differences from those in the 5-9 years age group and those aged >30 years (Dunn's post-hoc test: p < .0001). Among the 19 detection numerals in SPP-3, we found that the correct answer rates of six numerals decreased with aging, and the colors of the numerals and their backgrounds all located parallel to the tritanopic confusion line.Conclusions: Using SPP-3, we confirmed that aging influenced color vision, even in normal eyes with a good BCVA (20/20 or better). The total number of correct answers of SPP-3 was the highest in subjects aged 10-24 years and had already begun to decline in those in their 30s.

Color vision deficiency in preschool children: the multi-ethnic pediatric eye disease study

PURPOSE

To determine the sex- and ethnicity-specific prevalence of color vision deficiency (CVD) in black, Asian, Hispanic, and non-Hispanic white preschool children.

DESIGN

Population-based, cross-sectional study.

PARTICIPANTS

The Multi-Ethnic Pediatric Eye Disease Study is a population-based evaluation of the prevalence of vision disorders in children in Southern California. A total of 5960 subjects 30 to 72 months of age were recruited for the study, of whom 4177 were able to complete color vision testing (1265 black, 812 Asian, 1280 Hispanic, and 820 non-Hispanic white).

METHODS

Color vision testing was performed using Color Vision Testing Made Easy color plates (Home Vision Care, Gulf Breeze, FL), and diagnostic confirmatory testing was performed using the Waggoner HRR Diagnostic Test color plates (Home Vision Care).

MAIN OUTCOME MEASURES

Testability of color vision in preschool children between 30 and 72 months of age and prevalence of CVD stratified by age, sex, and ethnicity.

RESULTS

Testability was 17% in children younger than 37 months of age, increasing to 57% in children 37 to 48 months of age, 89% in children 49 to 60 months of age, and 98% in children 61 to 72 months of age. The prevalence of CVD among boys was 1.4% for black, 3.1% for Asian, 2.6% for Hispanic, and 5.6% for non-Hispanic white children; the prevalence in girls was 0.0% to 0.5% for all ethnicities. The ethnic difference in CVD was statistically significant between black and non-Hispanic white children (P = 0.0003) and between Hispanic and non-Hispanic white children (P = 0.02). In boys, most CVD cases were either deutan (51%) or protan (34%); 32% were classified as mild, 15% as moderate, and 41% as severe.

CONCLUSIONS

Testability for CVD in preschool children is high by 4 years of age. The prevalence of CVD in preschool boys varies by ethnicity, with the highest prevalence in non-Hispanic white and lowest in black children.

Effect of petroleum derivatives and solvents on colour perception

BACKGROUND

Occupational exposure to various neurotoxic chemicals has been shown to be associated with colour vision impairment. It seems that this can occur at low exposure levels, sometimes well below the recommended occupational threshold limits. This study was undertaken to determine the effect of exposure to petroleum derivatives (polyethylene, polystyrene) and solvents (perchloroethylene) on colour perception.

METHODS

Colour vision was assessed using the Ishihara plates, the D-15 test and the Farnsworth Munsell 100 Hue test. Two factories using petroleum derivatives and three dry cleaning premises were chosen at random. A total of 93 apparently healthy employees were recruited from the five workplaces. Two age-matched control groups comprising 56 people, who were support staff of the university with no exposure to petroleum, solvents or their derivatives, were also recruited.

RESULTS

All subjects passed the Ishihara test, showing that none had a congenital red-green defect. Some of the exposed employees failed the D-15 and had abnormally high FM100 Hue scores. All control subjects passed all the colour vision tests. The D-15 test showed that 28 per cent (26 of 93) of exposed employees had a colour vision defect whereas the FM 100 Hue test found that 63 per cent (59 of 93) had a colour vision defect. Most defects were of the blue-yellow type (22.6 per cent) when using the D-15 test. However, with the FM 100 Hue test, most defects were of the non-polar type with no specific axis (50.5 per cent). Mean total error scores calculated from the FM100 Hue test for exposed employees were statistically significantly higher than those of the control subjects.

CONCLUSION

Employees directly exposed to petroleum derivatives and solvents have a higher risk of acquiring colour vision defects compared to subjects who are not.

Prevalence of congenital red-green color vision defects in Arab boys from Riyadh, Saudi Arabia

The prevalence of congenital red-green color vision defects (CVDS) is both racial and gender dependent. Red-green color vision defects (CVDS) have been screened for among Arab boys from Riyadh, Saudi Arabia, by using both the Ishihara plates and the D 15 test. The results indicate a prevalence of 2.93%. Deutan defect was present in 1.95% of the subjects, protan defect in 0.49% and unclassified color defect in 0.49%. This result confirms the previously reported low prevalence of congenital red-green CVDS among adult Arab males from the central region of Saudi Arabia.