On each date, three infected mice and two age-matched uninfected control mice were sacrificed; left eyeballs from infect每次牺牲三只感染鼠与二只同龄未感染鼠，藉解剖显微镜检视左眼是否出现幼虫，右眼部分则加以包埋后进行组织病理学检测。