ObjectiveTerson's syndrome, a complication of visual function, has occasionally been reported in patients with aneurysmal subarachnoid hemorrhage (SAH), however the factors responsible for Terson's syndrome in aneurysmal SAH patients have not yet been fully clarified. In this study, we report on potential risk factors for prediction and diagnosis of Terson's syndrome in the earlier stage of the disease course in patients with aneurysmal SAH.Materials and MethodsThe authors retrospectively analyzed the data of 322 consecutive patients who suffered from aneurysmal SAH in a single institution between Jan. 2007 and Dec. 2013. Medical records including demographics, neurologic examination, and radiologic images were collected to clarify the risk factors of Terson's syndrome. Patients with visual problem were consulted to the Department of Ophthalmology.ResultsAmong 332 patients with aneurysmal SAH, 34 patients were diagnosed as Terson's syndrome. Four individual factors, including World Federation of Neurosurgical Societies (WFNS) grade at admission, aneurysm size, method of operation, and Glasgow outcome scale showed statistically significant association with occurrence of Terson's syndrome. Of these, WFNS grade at admission, aneurysm size, and method of operation showed strong association with Terson's syndrome in multivariate analysis. Terson's syndrome accompanied by papilledema due to increased intracranial pressure led to permanent visual complication.ConclusionIn patients with aneurysmal SAH, the patients' WFNS grade at admission, the size of the aneurysms, particularly the diameter of the aneurysm dome, and the method of operation might influence development of Terson's syndrome.