Interobserver reliability when using the Van Herick method to measure anterior chamber depth

Abstract

Introduction: The Van Herick method is a quick and easy way to estimate anterior chamber depth, which allows grading of patients according to the likelihood of having primary acute closed-angle glaucoma. However, as the test is highly subjective, measurements and thus grading may vary between observers. Aim: The aim of this study was to investigate the degree of variation of Van Herick scores among observers and to investigate agreement between temporal and nasal scores. Materials and methods: A total of 15 observers measured the temporal and nasal Van Herick scores from 18 patients, grouped into cohorts at outpatient glaucoma and corneal clinic. Analysis of data involved assigning a patient to a Van Herick grade based on the median score and then determining the mean standard deviation and percentage consistency for each grade. Results: We found that Grades 1 and 4 had a high mean percentage consistency (80% and 84.6%, respectively) and a low mean standard deviation (0.45 and 0.26, respectively). Grades 2 and 3 had low mean percentage consistencies (57.5 and 5, respectively) and high mean standard deviations (0.71 and 0.89, respectively). The temporal and nasal scores showed good agreement (κ = 0.61P < 0.001). Conclusion: The Van Herick score has a good interobserver reliability for Grades 1 and 4; however, Grades 2 and 3 require further tests such as gonioscopy or ocular coherence tomography. Temporal and nasal scores demonstrated good agreement; therefore, if the nasal score cannot be measured due to nasal bridge size, the temporal can be used as an approximation.

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