The Study of Normal Intraorbital Positions of The Rectus Muscles.

Heo, Hwan; Park, Sang Woo; Park, Yeoung Geol

Original Article

Journal of the Korean Ophthalmological Society 2005;46(10):1675-1683.
Published online October 31, 2005.

The Study of Normal Intraorbital Positions of The Rectus Muscles.

Hwan Heo, Sang Woo Park, Yeoung Geol Park

Department of Ophthalmology, Chonnam National University Medical School and Hospital, Chonnam National Research Institute for Medical Sciences, Gwangju, Korea. exoeso2003@yahoo.co.kr

정상인에서 안와내 직근의 위치에 대한 연구

허환,박상우,박영걸

Department of Ophthalmology, Chonnam National University Medical School & Hospital, Chonnam National Research Institute for Medical Sciences, Gwangju, Korea

Correspondence: Hwan Heo M.D

Abstract

PURPOSE
In order to propose reference values useful for in diagnosing the strabismus related to the abnormal intraorbital pathway of rectus muscles, we evaluated the intraorbital positions and angles of each rectus muscle in normal subjects. METHODS: Using previously scanned orbital MRI and orbital CT of patients who did not show any strabismus or organic disease in the orbit, we calculated the angles of each rectus muscle in the orbit, and compared the results with those of a patient with large angle exotropia. RESULTS: Using orbital MRI and orbital CT, the normal angles of each rectus muscles 10 mm posterior to the globe center were -5.1+/-3.4 and -1.5+/-6.0 degrees in the medial rectus, 185.8+/-8.1 and 180.8+/-6.9 degrees in the lateral rectus, 98.1+/-6.03 and 87.9+/-6.7 degrees in the superior rectus, and -79.7+/-6.1 and -83.1+/-11.7 degrees in the inferior rectus, respectively. In the patient with large angle exotropia, each rectus muscle showed orbital pathways similar to the normal patients. CONCLUSIONS: We evaluated the normal positions and angles of each rectus muscle in the orbit. The results may be useful in diagnosing the strabismus related to an abnormal orbital pathway of rectus muscles.

Key Words: Extraocular muscles;Orbital pathway;Strabismus