• Neuro-Ophthalmology/Orbit

    This case report describes 3 patients who developed an afferent pupillary defect following microsurgical clipping of an anterior communicating artery aneurysm (ACoA).

    Study design

    Three patients developed an afferent pupillary defect due to compressive optic neuropathy that occurred because of a shift in the position of the aneurysm clip after ACoA clipping. In each case, the clip head was superior to the optic nerve and was pushed anteriorly, thus compressing the optic nerve. 


    All patients underwent re-exploration and the aneurysm clips were repositioned. Near-complete restoration of vision was achieved in all 3 patients.


    The patients were not examined by neuro-ophthalmologists. Formal visual field testing was not performed. Eye exams were performed bedside in the hospital and may have been limited in scope.

    Clinical significance

    Brain shifts following microsurgical clip ligation of ACoAs can lead to mechanical compression of the optic nerve. Pre- and post-operative examination of patients who have ophthalmic artery and/or ACoAs can help identify potential optic nerve compression. Recognition of this condition and early repositioning of clips may reverse vision loss.