FREQUENCY AND UNDERLYING FACTORS OF MYOPIA AMONG MEDICAL STUDENTS

Introduction: Refractive error may be defined as a state in which the optical system of the non- accommodating eye fails to bring parallel rays of light to focus on the retina. Especially myopia has become a very common problem. Myopia is a refractive error in which eye fails to see distant objects properly. Objectives: To estimate the frequency of myopia among MBBS students of AIMC; to point out the under lying factors of myopia; and to compare these factors among myopics and emmetropes in a Cross Sectional Comparative, study form March 2010 to September 2010. Materials and Methods: Two hundred and two (202) students from all the five M.B.B.S classes were examined. Around 40 students were selected from each class by systematic random sampling technique, their visual acuity was checked using Snellen’s Chart and Diopters were checked in Eye Deptt. To assess factors a semi-structured questionnaire was filled by the interviewer. Results: Frequency of myopia was observed as 57.6%. Mean refractive error was -2.12D. A total of 61% of females and 51.5% of males were myopic. First and second year students had greater per- centage of myopia with 61.1%. Out of 117 myopic students, 71 (60.7%) had positive family history of myopia, whereas 22 (18.8%) did not. (p = 0.000003). The mean reading hours per day of myopics were 3.31, while others had an average of 3.60 hours daily. Difference between daily time spent on writing activity by myopics and non-myopics was insignificant (p = 0.544). The myopics watched television for an average of 2.24 hours daily and the non-myopics had a mean of 2.71 hours of watching television daily. Similarly, our study did not show any significant statistical relationship between working on computer, sleeping habits of students and amount of physical exercise done daily (p = 0.266, 0.968 and 0.305 respectively). Dietary factors did not show any significant rela- tionship with myopia. Conclusion: Prevalence of myopia was high among AIMC students (57.6%). 1st and 2nd year stu- dents had greater percentage indicating that it is increasing in the younger age group. Signifi- cance of genetic predisposition was well appreciated in our study.