Histological And Ultrastructural Studies Of Extraocular Muscle In Comitant Strabismus

Background & Objective The pathogeny of comitant strabismus haved not defined. Recently, the research haved indicated that the extraocular muscles haved pathological diversity. To investigate the mechanism for comitant strabismus by observing extrocular muscle by elector microscope and determined the rate of myofiber area/collagen fiber area in Masson staining under light microscope.Methods Fifty cases with comitant strabismus and twelve health controls were included in this study, fifty cases with comitant strabismus were divided into three groups by different ages. Specimens of the extraocular muscles were taken during operation and than examined by light microscope and electron microscope. Determined the rate of myofiber area/collagen fiber area in Masson staining under light microscope.Results There was significant difference in the rate of myofiber area/collagen fiber area between comitant strabismus and health controls .Extraocular muscles withcomitant strabismus in three groups haved pathological diversity and more apparent changes were observed with advancing age. The rates of myofiber area/collagen fiber area were significant difference in≤6Y(0.242523±0.0628391);6～12Y(0.188544± 0.0326772);>12Y(0.151233 ±0.0464508). the rate was negatively correlated with the age . But there was no significant difference in the rate of myofiber area/collagen fiber area between comitant esotropia and comitant exotropia.Conclusion Extraocular muscles with comitant strabismus have pathological diversity and more apparent changes were observed with advancing age. Early operation on comitant strabismus is preferable in case any serious pathological change should happan to the muscles to deter visual function fyom restoring.