Inertional pattern of the inferior oblique mucle

Purpoe We aimed to define the anatomy and anatomic variation of the inferior oblique mucle (IO) and claify it inertional pattern with photograph and drawing. Deign Cohort tudy. Method Thi tudy included 60 intact orbit of 30 (17 male and 13 female) embalmed adult cadaver. The inferior oblique mucle wa diected microanatomically from the origin to the inertion by uing a diection microcope. For each pecimen, we photographed the inertional pattern of the mucle. A Vernier caliper wa ued to meaure the width and length of the mucle at the inertion and from the diviion to the inertion, repectively. Reult We claified the inferior oblique mucle into four group according to the inertional pattern. In the firt group, the mucle wa formed of only one belly (“ingle,” five eye, 8.3%). In the econd group, the mucle had a main and a econdary belly (“double,” 30 eye, 50%). In the third group, the mucle had three bellie (“triple,” 16 eye, 26.6%). In the fourth group, the mucle had more than three bellie (“multiple,” 9 eye, 15%). Concluion We found double, triple, and multiple mucle bellie in 91.7% of 60 cadaveric eye. Ocular urgeon who do not frequently perform inferior oblique urgery hould carefully examine the inferior temporal quadrant of the clera to avoid miing portion of the inferior oblique mucle at the time of urgery.