What treatment options exist? Which do you think would be most likely indicated? Why?
In general intracranial aneurysms can be treated either endovascularly (with coils +/- stents) or surgically (clips +/- excision). The latter would be favoured in this case for a number of reasons. Firstly coiling thrombosed aneurysms is not ideal and a good coil packing is difficult to achieve and re-canalisation is common. Secondly, and more importantly in this case, coiling would not reduce the mass effect on the optic apparatus, at least not in the short term, and the chances of visual improvement would be reduced.
CTA of the circle of Willis demonstrates a giant peripherally calcified ACA/Acom aneurysm. It is mostly thrombosed with a central lumen much smaller than the outer sac.