AIM:Toinvestigatechangesinfundusexcyclotorsionafterinferiorobliquemyectomyormyotomy.METHODS:Therecordsof21patientsundergoingstrabismussurgerybyasinglesurgeonbetween2009and2012wereexamined.Onlypatientswhohadundergoneaninferiorobliquemyectomyormyotomy,withorwithouthorizontalrectusmusclesurgery,wereevaluated.Digitalfundusphotographswereobtained,andtheangleformedbyahorizontallinepassingthroughtheopticdisccenterandareferencelineconnectingthefoveolaandopticdisccenterwasmeasured.Associatedclinicalfactorsexaminedincludeageatthetimeofsurgery,presenceorabsenceofaheadtilt,degreeofpreoperativeverticaldeviation,torsionalangle,inferiorobliquemuscleoveraction/superiorobliquemuscleunderaction,andsurgerylaterality.Whethertheprocedurewasperformedaloneorincombinationwithahorizontalrectusmusclesurgerywasalsoexamined.RESULTS:Meanpreoperativetorsionalanglewas12.0±6.4°,whichdecreasedto6.9±5.7°aftersurgery(P<0.001,pairedt-test).Torsionalanglealsodecreasedfrom15.1±7.0°to6.2±4.3°inthemyectomygroup(P<0.001,pairedt-test)buttherewerenosignificantchangesinthemyotomygroup(P=0.093,Wilcoxonsignedranktest).Multivariablelinearregressionanalysisshowedthatpreoperativetorsionalangle,degreeofinferiorobliqueoveraction,andageatsurgeryindependentlyandsignificantlyaffectedpostoperativetorsionalangle.CONCLUSION:Meantorsionalangledecreasedafterinferiorobliquemyectomy.Degreeofpreoperativetorsionalangle,inferiorobliqueoveraction,andageatsurgeryinfluencepostoperativetorsionalangle.
