Study Of The IGF-1and AnnexinA1Expression In Overacting Inferior Oblique Muscle

ObjectiveThe overaction of inferior oblique muscle is common in patients with strabismus,but the pathogenesis is not clear. Currently it’s fundamental research focus in the oblique muscle pathology change and muscle satellite cell activation, and study on biological factor expression is rare.The purpose of the topic is to observe the morphologic change of the overacting inferior oblique muscle,to evaluate the expression of IGF-1(insulin-like growth factor1) and AnxAl(AnnexinAl) in the normal and overacting inferior oblique muscle.To investigate the influence of IGF-1and AnxAl to the overacting inferior oblique muscle.MethodsThe case group was to collect16cases with constitutional overaction of inferior oblique muscle,16cases with sencondary overaction of inferior oblique muscle by random,the control group was the normal inferior oblique muscle.Intercepted the overacting inferior oblique muscle with4-6mm from patients undergoing surgical resection,the normal inferior oblique muscle was obtained from patients undergoing eyeball removal and corneal transplantation donors. Fixed and scliced the muscle tissue, then carried out routine HE stain and immunohistochemistry stain. Observed the morphologic of the inferior oblique muscle and measured the IOD(integrated optic density) according to the expression of IGF-1and AnxAl in the inferior oblique muscles.ResultsThe constitutional overaction inferior oblique muscle fiber diameter,distribution and arrangement is irregular, some part of the muscle fiber diameter enlarge, it’s enlargement of muscle fiber diameter compared with the normal inferior oblique muscle proportion is higher.There are nuclear ingression phenomenon and hyaline degeneration in some muscle fiber.The secondary overaction oblique muscle has the similar morphological change.The integrated optic density of IGF1and AnxAl in constitutional and secondary group is13.144±3.478,12.062±3.375and12.543±3.023,13.802±3.389.Signifieant differences exist in the expression of IGF1and AnxA1,when compared with the normal group(5.740±0.611,5.532±0.665)P<0.01).There is no significant difference between the constitutional and secondary overaction oblique muscle group in the expression of IGF1and AnxAl (P>0.05)ConclusionThe constitutional overaction inferior oblique muscle and the secondary overaction oblique muscle has the similar morphological change.The muscle fiber diameter,distribution and arrangement is irregular.There are nuclear ingression phenomenon and hyaline degeneration in some muscle fiber.These morphological changes may led to the overaction of inferior oblique muscle.The expression of IGF1and AnxAl increase in the overaction oblique muscle than normal inferior oblique muscle group.The inferior oblique muscle overaction mechanism and expression of IGF1and AnxAl changes may be related.