Shanmugam Srinivasan
BACKGROUND Colour blindness is usually caused by X linked recessive inheritance in which total colour blindness is rare while common is partial colour blindness. Among the partial colour blindness patients red-green colour blindness is more common followed by blue-yellow colour blindness. Partial colour blindness occurs in 8% of male population and 0.5% of female population with redgreen blindness. The aim of the study is to identify the colour blindness among medical, paramedical staff including nursing students, job seeking persons from police, pilot, and candidates of various technical, engineering and routine master health check-up; about 3500 cases were screened at ophthalmology department, Government Kilpauk Medical College, Chennai during the period September 2017 to December 2018. MATERIALS AND METHODS Police personnel coming for routine eye check-up, candidates coming for master health check-up, job seekers coming for evaluation of eye fitness, medical and paramedical staff including nursing students were examined from September 2017 to December 2018 and the total number of cases was 3500. Routine ophthalmological examinations were carried out in all cases including slit lamp examination, visual acuity by Snellen’s chart, Colour vision by Ishihara colour vision chart, intra ocular pressure by applanation tonometer, direct and indirect ophthalmoscopic examination and fundus photography. RESULTS In our study, we detected five male patients and one female patient suffering from defective colour vision. In male gender, out of 5 persons, 4 were suffering from partial colour blindness and 1 from total colour blindness with normal visual acuity, whereas only one female was detected to be suffering from partial colour blindness. All the partial colour blindness cases were having defect in appreciation of red and green colours, and they are inherited. Percentage of colour blindness in our case study is 0.17%. CONCLUSION As per our study, the colour vision deficiency cases were only partial in nature, particularly to red and green without any symptomatology. All were found to be suffering from colour blindness incidentally detected only during routine eye check-up, with Ishihara colour vision chart. Since, in India the defective colour vision is a remark for certain jobs like army, driving, pilot, engineering technical persons and police job, all the individuals must be checked for normal colour vision during school age itself.
