Analysis of the structure and function of the extraocular muscle connective tissue in rabbit

Background The extraocular muscles (EOMs) Pulley in primate is related to the function of EOMs,but there are arguments about that.The location of rabbit's eyes is different from the primate.Study on the structure of the extraocular muscle connective tissue in rabbit may play a role to analyze the function of the EOMs Pulley.Objective The structure of the connective tissue around EOMs in rabbit was studied,the difference between this structure in rabbit and homan' s EOMs Pulley in past reports was analyzed,and then,the role of EOMs Pulley to ocular movement was investigated.Methods Five adult rabbits were involved.The gross anatomy of an orbit in each rabbit was observed.The other orbit was processed with paraffin imbedding and coronal serial sections.A murine monocolonal antibody to α-smooth muscle actin(α-SMA) was used to show the smooth muscle,while Weigert stain was used to show muscle and collagen,and Masson trichrome stain to show the elastin.Results An encircling ring of collagen circled every EOM.The collagen ring was thin and connected to the orbital layer muscle fiber loosely.Collagen tissues coupled to adjacent EOMs.Less elastin fibers and scanty the smooth muscle cells were embedded in the collagen.Conclusions The connective tissue around rectus in rabbit is different from that in human with developed binocular ocular movements.It shows that connective tissue around EOMs may be related to the function of ocular movements. Key words: Extraocular muscle;  Connective tissue;  Ocular movement;  Pulley;  Rabbit;  Human