The effects of hydrocephalus on optic nerve in patients with intracranial masses

Objective: In patients with increased intracranial pressure, accurately detecting increased intracranial pressure is crucial for improving long-term neurological outcomes. The measurement of optic nerve sheath diameter is a non-invasive, practical, and economical method used to identify increased intracranial pressure. The purpose of this study is to detect the preoperative and postoperative changes in optic nerve sheath diameter in patients with intracranial mass, to correlate these changes with optic nerve diameter variations, and to evaluate the impact of hydrocephalus on these alterations. Material and Method: This study was conducted with patients who presented to our clinic with complaints of intracranial mass, were decided for surgery, and underwent surgical procedures. The study included the patients' age, gender, the diameter of the right and left optic nerve sheath measured in cranial magnetic resonance imaging before and after surgery, the arithmetic average of the optic nerve sheath diameter, right and left optic nerve diameter, the arithmetic average of optic nerve diameter, Evans' ratio, the nature and grade of the mass, tumor localization, volume measurement based on size, Glasgow coma scale, presence of hydrocephalus, and the degree of hydrocephalus. Findings: In the evaluation of preoperative and postoperative bilateral optic nerve and optic nerve sheath diameter measurements of the 91 patients without hydrocephalus and 82 patients with hydrocephalus included in the study; it was observed that the optic nerve and optic nerve sheath diameter measurement values were different preoperatively and postoperatively, with a significant decrease in the optic nerve sheath diameter in all groups in postoperative measurements, while the optic nerve diameter significantly increased. However, it was seen that the impact of hydrocephalus on the optic nerve and optic nerve sheath did not show a significant difference compared to the effect of intracranial mass-related increase in intracranial pressure on the optic nerve and optic nerve sheath. Conclusion: Although there was no significant difference between the effects of hydrocephalus and intracranial mass-related increase in intracranial pressure on the optic nerve and optic nerve sheath, it was observed that hydrocephalus increased intracranial pressure when considering the Evans ratio. It has been determined that as ventricular dilatation increases, so does intracranial pressure, which leads to an increase in the diameter of the optic nerve sheath, resulting in papilledema and thinning of the optic nerve. These findings indicate the importance of early cerebrospinal fluid diversion and monitoring optic nerve sheath diameter in the management of intracranial pressure in patients with hydrocephalus and intracranial mass.