EVALUATION OF COLOUR VISION DEFECTS USING D-15 IN RELATION WITH IRIS COLOUR AND PUPIL SIZE; A CROSS-SECTIONAL STUDY

Abstract

Introduction: Colour of iris is associated with race and may show hereditary patterns. In this context it may be associated with colour vision defects and size of pupil. This study was conducted to determine whether variations in iris colour and pupil size were correlated with colour vision defects as measured by the D-15 test.

Material & Methods: A proforma based cross-sectional study was conducted at College of Ophthalmology and Allied Vision Sciences in Mayo Hospital, Lahore. Data was collected from September 2023 to December 2023. The study was approved by the Ethical review board of the College of Ophthalmology and Allied Vision Sciences. The sample size was 70 subjects, with the inclusion criteria being individuals aged 18 or older, having normal colour vision or colour vision deficiency, and able to read and understand D15 instructions. Exclusion criteria included those with a history of eye disease or injury, taking medication that could affect colour vision, or those unable to complete the D15 due to physical or cognitive limitations. Statistical significance was calculated using Chi-square test. P value<0.05 was considered significant.

Results: Brown iris colour was common (51.47%) with predominance in females. Pupil size in the range of 6.6-7.0mm was higher in females. Two patients had colour blindness with iris colour of brown and amber (P=0.613) and their pupil size was between 6.6mm to 7.5mm (0.047) depicting positive correlation.

Conclusion: Colour vision defects were not significantly influenced by iris colour; however, larger pupil sizes (6.6-7.5mm) showed a noteworthy correlation with these vision problems.