[Observation on the morphology differences of ocular rectus pulley between preschool children and adults]

To study the morphology differences of ocular rectus muscles pulley between preschool children and adults.

It was an experimental research. Ten fresh cadaver orbits (five children and five adults) were fixed in situ and serially sectioned at 4 microm thickness. Every section was stained with Masson's trichrome and picrosirius red methods. After being stained, extraocular muscle pulley in typical sections was examined through gross anatomy and light microscopy. Two-factor analysis of variance for quantitative data was used in statistical treatment.

Near the equator of the globe, the children and adults' extraocular muscle pulleys were all at the points where the rectus penetrate posterior Tenon's fascia, encircling the rectus orbit side by fiber ring structure. There were pulley bands among rectus pulleys. The rectus pulley length and the origin distance from the corneoscleral limbus of the children were significantly less than those from the adult group (P < 0.05). The main composition of the children rectus pulley was similar to that of the adults, but the smooth muscle and collagen type III fibers contents of the medial rectus pulley in children were significantly greater than those in the adults group (P < 0.05). Collagen type I fibers in the children were significantly less than that of the adults group (P < 0.05).

There are morphological differences in rectus pulley between preschool children and adults, which provides an anatomic basis for the better understanding of the pathogenesis of strabismus.