Optic nerve sheath diameter and axial length in patients with optic disc drusen: a cross-sectional study

Abstract

Measuring the optic nerve sheath diameter (ONSD) and the anteroposterior axial length of the eye in patients with optic disc drusen (ODD). A total of 43 healthy volunteers and41patients with ODD were included in the study.The ONSD and axial length were measured in theposterior positionusing an ultrasound device (E-Z Scan AB5500 +)probe with a 10MHz frequency. The ONSD was measured 3mm behind the globe wall.Receiver operating characteristic (ROC) curve analysis was performed to determine patients with ODD using ONSD.Any p-value of < 0.05 was accepted to demonstrate significance. The ONSD was significantly higher(5.2mm and 4.8mm, p = 0.006,respectively),andthe axial length was shorter(21.82 ± 2.15mmand23.27 ± 1.96mm,p = 0.002,respectively) in the ODD group.The spherical equivalent was more commonly seen as hypermetropic in the ODD group (1.00 [- 0.85 to 1.75]).In the ROCanalysisto determine the ONSD value in ODD diagnosis, the area under the curvewas 0.6754 (95% confidence interval 0.559-0.788, p = 0.006).ONSD cutoff of 5.70mm had a sensitivity of 0.366 and a specificity of 0.907 to diagnose ODD. In this study, the ONSD was significantly higher in the ODD group. The axial length was shorter in the ODD group.This study is the first in the literature to evaluate the ONSD in patients with optic disc drusen.Further studies are needed in this regard.