Optic Nerve Head Microvascular Changes Associated with Intracranial Aneurysms

The aim of our study is to report optic nerve head (ONH) microvascular changes secondary to intracranial saccular aneurysms, evaluated by optic coherence tomography angiography.

A prospective study was conducted on consecutive intracranial saccular aneurysm patients who underwent neurosurgical intervention and consulted for ophthalmic evaluation at the post-operative period. Comprehensive ophthalmic evaluation, including best-corrected visual acuity, manifest refraction, color vision, pupillary light reflexes, intraocular pressure, slit-lamp biomicroscopy, fundoscopy, and investigation of the function of cranial nerves, was performed. Demographical and clinical data of eyes with intracranial aneurysm (Group 1) were compared to those of age-matched controls (Group 2). In patients with unilateral intracranial aneurysm, microvascular indices of the ipsilateral eye were also compared with those of the contralateral eye.

Twenty-eight eyes of 16 patients in Group 1 and 32 eyes of 16 age-matched healthy controls in Group 2 were included in the study. In Group 1, only 1 patient was diagnosed incidentally, whereas the remaining 15 patients were diagnosed after subarachnoid hemorrhage (SAH). ONH microvascular indices were similar in both groups (p>0.05). Both vascular density and thickness were decreased at the nasal inferior sector of ONH in Group 1, compared to Group 2; however, these differences were statistically insignificant. In Group 1, 8 patients have unilateral intracranial aneurysm. Microvascular indices at the ipsilateral eye were statistically insignificantly increased compared to those at the contralateral eye of patients with unilateral intracranial aneurysm.

Intracranial saccular aneurysms, associated SAH, or neurosurgical intervention did not seem to cause any significant change in ONH microvascular indices. Further studies with a larger sample size and evaluating intracranial aneurysms located in different anatomical regions will contribute to the interpretation of the present results.