It may be necessary to have various guidelines for strabismus surgery because of anatomical differences among ethnic groups, a study found.
The goal of the study had three parts: to compare the extraocular muscle insertion locations among Taiwanese (Han Chinese) subjects who did or did not have strabismus; to investigate extraocular muscle insertion locations among Taiwanese subjects and subjects from Western countries to determine differences; and if there were differences, to investigate if applying surgical guidelines developed for Western subjects resulted in undesirable outcomes in Taiwanese subjects.
The researchers reviewed patient medical records in the retrospective study. The 123 subjects in the strabismus group had underwent an initial strabismus procedure performed between 2005 and 2008. The 60 subjects in the control group included those who had received an encircling scleral buckle procedure in 2007 and did not have a strabismus diagnosis.
Results showed that among Taiwanese subjects, extraocular muscle insertion locations were not significantly different. However, compared with Western subjects, Taiwanese subjects had shorter distances from the insertion location to the limbus of the inferior rectus, lateral rectus and superior rectus.
“Extraocular muscle insertion locations for the Taiwanese population in this study significantly differed from those reported in studies of Western populations,” the study authors said. “Therefore, surgical guidelines for performing lateral rectus recession to treat exotropia in Western populations may be inappropriate for Taiwanese and other Asian populations.”