Objectives: Ultrasound measured optic nerve sheath diameter is a noninvasive, nonirradiating tool for estimating intracranial hypertension. The objective of this systematic review and meta-analysis is summarization of the current evidence for accuracy of ultrasound measured optic nerve sheath diameter in detecting intracranial hypertension in pediatric patients.
Data sources: Medical subject heading terms were used to search MEDLINE, Embase, Google Scholar, Web of Science, and the Cochrane Library for relevant citations. Publications from January 1, 2000, to June 30, 2019, were included in the search strategy.
Study selection: Studies were included if they involved patients less than 18 years, where ultrasound measured optic nerve sheath diameter was compared to conventional, nonophthalmic tests for intracranial hypertension. Studies were excluded if there was insufficient data to compute a sensitivity/specificity table. Case reports, case series, and manuscripts not published in English were also excluded.
Data extraction: The initial search returned 573 citations. Of these, 57 were selected for review.
Data synthesis: Eleven citations were included in the final meta-analysis. A bivariate random-effects meta-analysis was performed, which revealed a pooled sensitivity for ultrasound measured optic nerve sheath diameter of 93% (95% CI, 74-99%), a specificity of 74% (95% CI, 52-88%), and a diagnostic odds ratio of 39.00 (95% CI, 4.16-365.32). The area under the curve of the hierarchical summary receiver operating characteristic curve was 0.90 (95% CI, 0.87-0.93). Subgroup analyses of the test's performance evaluating new-onset intracranial hypertension and in comparison to invasively measured intracranial pressure were performed. The test performance in these instances was similar to findings in the primary analysis.
Conclusions: We are unable to identify a threshold value in ultrasound measured optic nerve sheath diameter for the determination of intracranial hypertension in children. Even though the ultrasound measured optic nerve sheath diameter measurement is highly sensitive to the presence of increased intracranial pressure, the test has only moderate specificity. Therefore, other confirmatory methods and further investigation is necessary in the clinical care of children. The technique is likely not sufficiently precise for clinical use in the absence of other confirmatory methods, and further investigation is necessary to determine clinical protocols for its use in children.