[Spontaneous dislocation to the anterior chamber of a lens luxated in the vitreous body: two cases].

BACKGROUND

Compared to lens luxations into the vitreous body, luxations into the anterior chamber are rare. We report on two patients in whom a lens luxation into the vitreous body was followed by a luxation into the anterior chamber.

CASE REPORT: In a 61-year old male patient and a 47-year old female patient a lens luxation into the vitreous body occurred after a blunt ocular trauma and as a result of Marfan syndrome, respectively. During follow-up the patients presented with a spontaneous lens luxation into the anterior chamber. In both cases a YAG iridotomy and a surgical lens extraction were immediately performed.

CONCLUSION

As a result of whiplash-like movements of the vitreous body, a dislocation of a lens luxated into the vitreous body, into the retroiridal or intrapupillary space may occur. This may be facilitated by focally undamaged zonular fibers. The immediately retroiridal lens position may cause a pupillary block with fluid misdirection into the space behind the iris-lens diaphragm resulting in a consecutive pressure increase in this space. This pressure rise causes an anterior movement of the lens and may be followed by a complete dislocation into the anterior chamber especially in the case of coexisting traumatic mydriasis. As a result of this lens dislocation into the anterior chamber an inverse pupillary block develops. This situation necessitates an iridotomy prior to the surgical lens extraction.