Sonographic evaluation of the optic nerve sheath diameter and anterior chamber depth of the eye among apparently healthy adults in Kano, Nigeria

Abstract

Background: Measurement of optic nerve sheath diameter (ONSD) and anterior chamber depth (ACD) by ultrasound is increasingly used as a marker to detect raised intracranial pressure and other eye pathologies. Knowledge of normal ONSD and ACD in a healthy population is essential in the interpretation of pathological conditions. Aim: The study aimed at evaluating the ONSD and ACD of the eye in apparently healthy adults in Kano State. Materials and Methods: This was a prospective and cross-sectional study conducted among apparently healthy adults in Kano State from April 2019 to October 2019. Using convenience sampling method, 384 adults participated in the study. An ethical approval was obtained from the Human Research and Ethics Committee of the Kano State Ministry of Health, and informed consent was obtained from all the selected participants. A portable digital ultrasound machine, Nortek CS 3 with a 7.5 MHz linear transducer, was used to obtain ACD and ONSD at 3 mm behind the globe, and the values were recorded in data capture sheet. The obtained data were analyzed using SPSS version 23.0. Results: The mean and standard deviation of the right and left ONSDs for males was 4.42 ± 1.38 mm and 4.44 ± 1.41 mm and for the females was 4.39 ± 1.31 mm and 4.41 ± 1.31, respectively. The mean and standard deviation of the right and left ACDs for males was 3.16 ± 0.37 mm and 3.14 ± 0.35 mm and for females was 3.12 ± 0.40 mm and 3.11 ± 1.39 mm, respectively. Conclusion: The study has established normative values for the ONSD and ACD of the eye in Kano State, Nigeria.