Abstract
The incidence of unilateral blindness and ophthalmoplegia after aneurysm surgery is very rare, especially in an anterior communicating artery (ACoA) aneurysm, but if it occurs, it is mainly caused by intra-operative nerve injury or retinal ischemia. We experienced 2 cases of unilateral blindness immediately after surgery. Both patients were classified into Hunt-Hess grade 1 and Fisher grade 3. Angiographic findings of these patients revealed that the aneurysms were located at the left ACoA. The aneurysms were clipped easily with minimal brain retraction via standard pterional craniotomy. In both cases, injury of the optic nerve during surgery was unlikely. Both patients complained of visual loss with ophthalmoplegia ipsilateral to the site of surgery on the 1st postoperative day and showed evidence of retinal ischemia with central retinal artery occlusion on fundoscopic examination. In our patients, we hypothesize that the complications were most likely related to the intra-orbital ischemia initiated by the collapse of the arterial and venous channels in the orbit and/or to the direct or indirect contusion on the intra-orbital structures. These situations could be produced by inadvertent pressure placed on the eyeball with a bulky retracted frontal skin flap. Visual acuity in both patients ranged from no light perception to finger-counting. Their external ophthalmoplegia had completely disappeared 2 weeks after surgery and visual acuity in one patient began to improve. But in the other patient, the condition was irreversible. The degree of visual recovery seems to be dependent on the duration and severity of retinal ischemia by orbital compression. Unfortunately, there is no satisfactory treatment. We recommend careful surgical manipulation, including the use of an eye shield just before aneurysm surgery to protect the ipsilateral eyeball.