Abstract:

Objective  To approach the mechanisms of traumatic myopia using ultrasound biomicroscopy(UBM).  Methods  24 cases(26 eyes) with blunt eye trauma were included in this study. Refraction and lens thickness were measured respectively with an autorefractometer and A-scan ultrasoundgraphy in the acute(3 days after blunt eye injury) and convalescent stages(2 weeks after injury). The cornea thickness(CT), central anterior chamber depth(CACD), trabecular ciliary process distance (TCPD), A-angle(AA) and the T values(TV) were measured by ultrasound bio-microscopy (UBM). 20 normal eyes as the control group were measured twice as  mentioned above. Results  The refraction, lens thickness, anterior chamber depth, TCPD, A-angle and T values had statistical difference between the acute and convalescent stages（P＜0.05） but cornea thickness had no change（P＞0.05）.  Conclusion  The mechanisms in traumatic myopia are related with ciliary spasm, shallower anterior chamber and thickened lens. But primitive factors resulting in these changes are diffuse edema of the ciliary body and anterior rotation of the entire ciliary body. UBM can measure  pathological changes in traumatic myopia and has important clinical value.

Key words: Eltrasound bio-microscopy ；Eye injury； Myopia；Pathogenesis