Comparison of duo-chrome test performed in astigmatic patients before and after cylindrical correction

Abstract

Purpose: The main objective of this study is to compare the results of the duo-chrome test performed in astigmatic patients before and after cylindrical correction.

Material & methods: A quasi experimental study was conducted on 42 patients having astigmatic refractive error. People aged 15-58 years were included in this study. The study group was taken without discrimination of gender and excluding those who were mentally retarded, who had other pathological disorders of the eye, uncooperative patients, those who were not willing to share their data. Data was collected on self-designed proforma after taking consent from patient. V.A of all astigmatic patients was assessed on log MAR visual acuity chart at 4m. Trial lenses and duo-chrome test screen was used.

Results: The mean value for difference in spherical component of right eyes after duo-chrome results was 0.61±0.34 (SE=0.05) and for the duo chrome results performed after cylindrical correction was 0.56±0.29 (SE=0.04). And in left eyes the mean value for difference in duo-chrome results before performing cylindrical correction was 0.53±0.36 (SE=0.05) and that performed afterwards was 0.50±0.31 (SE=0.04), p-values with paired sample t-test is 0.22 for right eyes and 0.45 for left eyes of the patients, which shows that duo-chrome test results before and after cylindrical correction show no significant difference.

Conclusion: It is concluded from this study that there is insignificant difference between the results of duo-chrome test before and after cylindrical correction. Hence, duo-chrome test is equally useful to be performed before and after correcting cylindrical component during refraction.