The Investigation Of The Extraocular Muscle Pulley Structure In Human Orbit

Objective: To observe the relationship between Pulley and classic anatomy structure of connective tissue around extraocular muscles (EOMs) in human orbit and search anatomic landmark for surgical manipulations of Pulleys for treatment of strabismus.Methods: Six human orbits fixed in situ, ages 38 weeks gestation to 83 years, were removed in continuity with orbit bone wall maintaining the orbit rims. The length from rectus pulleys anterior line to corresponding scleral insertion was measure respectively. EOMs and connective tissue surroundings were sectioned at 10 micro m thickness, and stained for collagen, elastin, and smooth muscle (SM).Results: Rectus pulleys were at the points where rectus muscles penetrate posterior Tenon's capsules, comprising a dense encirclement by collagen fibers. Check ligaments were as function as orbital suspension of rectus pulleys, which attaching to orbit rims. The ending line of orbital layer insertion into pulley was seen in all rectus muscles. The length fromrectus pulleys anterior line to corresponding scleral insertion was 9.58 + 0.89mm(MR); 11.33 + 0.55mm(SR); 11.67 + 0.56mm(IR); 12.50 + 0.41mm(LR) respectively.Conclusions: The ending line of orbital layer insertion into pulley could be as anatomic landmark as for surgical manipulations of Pulleys for treatment of strabismus. Heterotopic pulley position is a potential cause of incomitant strabismus.