Evaluation Of Retinal Nerve Fiber Layer Changes After Csf Diversion In Obstructive Hydrocephalus: A Prospective Interventional Study

Abstract

Background: Hydrocephalus is a neurological condition caused by excessive accumulation of cerebrospinal fluid (CSF) within the ventricles, leading to raised intracranial pressure (ICP) and papilledema. Persistent papilledema, if untreated, can result in irreversible optic atrophy. The primary aim of CSF diversion procedures such as ventriculoperitoneal (VP) shunt or endoscopic third ventriculostomy (ETV) is to lower ICP and relieve optic disc swelling. Optical Coherence Tomography (OCT) provides a non-invasive, objective method for measuring retinal nerve fiber layer (RNFL) thickness, serving as a surrogate marker for papilledema and ICP changes. Methods: This prospective interventional study was conducted in the Department of Neurosurgery, Dhaka Medical College and Hospital, from January 2019 to June 2020. Fourteen patients with obstructive hydrocephalus and bilateral papilledema were included following clinical and radiological confirmation. RNFL thickness was measured using OCT preoperatively and on the 10 th postoperative day after CSF diversion through VP shunt or ETV. Statistical analysis was performed using paired t-tests to determine significance. Results: The mean preoperative RNFL thickness in the right eye was 155.07 ± 50.23 µm and postoperatively 120.50 ± 36.38 µm (p < 0.001). For the left eye, the mean preoperative and postoperative RNFL thicknesses were 178.00 ± 51.33 µm and 116.43 ± 26.60 µm respectively (p < 0.001). Both VP shunt and ETV resulted in significant postoperative reductions in RNFL thickness, indicating effective ICP control. Conclusion: OCT-based RNFL measurement is a reliable and non-invasive tool for quantifying papilledema and monitoring treatment outcomes following CSF diversion in obstructive hydrocephalus. The significant postoperative reduction in RNFL thickness underscores its clinical utility as an objective marker for ICP normalization and visual prognosis.