Understanding and preventing visual loss in commotio retinae

R Medicine > R Medicine (General)

Blanch, Richard James ; Scott, Robert

University:University of Birmingham

Department:School of Clinical and Experimental Medicine

关键词: R Medicine;    R Medicine (General);   

Others  :  http://etheses.bham.ac.uk//id/eprint/5159/1/Blanch14PhD.pdf

来源: University of Birmingham eTheses Repository

【 摘 要 】

Commotio retinae describes retinal opacification following trauma and affected 16% of British soldiers suffering major trauma.The macula was affected in 55% of soldiers and 31% of civilian cases, permanently reducing vision to less than 6/9 in 26% of cases, associated with photoreceptor degeneration. In an experimental rat model, commotio retinae was more readily induced by high velocity ballistic injury (20m/s) than low velocity weight drop (2-7m/s). In rats, after experimentally induced commotio retinae, photoreceptors died by a combination of necrosis (central to the impact site) and apoptosis (peripheral to it), demonstrated by morphological changes on electron micrographs and TUNEL staining.Photoreceptor death after commotio retinae was associated with reduced ERG a-wave amplitude.Apoptosis occurred through the intrinsic pathway, mediated by caspase 9 but not involving any of the classical executioner caspases (3, 6 and 7).Inhibition of caspase 9 reduced photoreceptor death and improved retinal function, assessed by a-wave amplitude. Clinical studies suggested a protective effect of female gender after commotio retinae, but progesterone treatment increased photoreceptor death after ballistic injury in the experimental model.