Extraocular muscle insertion positions and outcomes of strabismus surgery: correlation analysis and anatomical comparison of Western and Chinese populations.

BACKGROUND/AIMS: To compare the insertion locations of extraocular muscles between Taiwanese (Han Chinese) and Western populations and to determine whether anatomical differences warrant different surgical guidelines.
METHODS: Insertion locations were compared between a Taiwanese population of subjects who had received surgical treatment for strabismus and a control group who had not. Insertion locations and surgical outcomes in the strabismus group were also compared with those reported in other countries.
RESULTS: In Taiwanese subjects, extraocular muscle insertion locations were not significantly different between strabismus subjects and controls. However, the distances from the insertion location to the limbus of the inferior rectus, lateral rectus and superior rectus were significantly shorter in the Taiwanese subjects than in Western populations.
CONCLUSION: Extraocular muscle insertion locations for the Taiwanese population in this study significantly differed from those reported in studies of Western populations. Therefore, surgical guidelines for performing lateral rectus recession to treat exotropia in Western populations may be inappropriate for Taiwanese and other Asian populations.