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

Area of Science:

• Ophthalmology
• Glaucoma Research
• Anterior Segment Imaging

Background:

• The Van Herick method is a rapid clinical technique for estimating anterior chamber depth.
• This estimation aids in grading patients for primary acute closed-angle glaucoma risk.
• Subjectivity in the Van Herick test can lead to observer-dependent variations in measurements and grading.

Purpose of the Study:

• To quantify the interobserver variability of Van Herick scores.
• To assess the agreement between temporal and nasal Van Herick measurements.
• To evaluate the reliability of Van Herick grading for primary acute closed-angle glaucoma.

Main Methods:

• Fifteen observers assessed temporal and nasal Van Herick scores in 18 patients.
• Patients were recruited from glaucoma and corneal outpatient clinics.
• Data analysis involved calculating median scores, mean standard deviations, and percentage consistency for each Van Herick grade.

Main Results:

• Grades 1 and 4 demonstrated high consistency (80% and 84.6%) with low standard deviations (0.45 and 0.26).
• Grades 2 and 3 exhibited lower consistency (57.5% and 5%) and higher standard deviations (0.71 and 0.89).
• Temporal and nasal Van Herick scores showed substantial agreement (κ = 0.61, P < 0.001).

Conclusions:

• The Van Herick method shows good interobserver reliability for Grades 1 and 4.
• Grades 2 and 3 Van Herick scores indicate significant variability, necessitating supplementary diagnostic tests like gonioscopy or OCT.
• Temporal and nasal measurements are in good agreement, allowing temporal measurements to substitute nasal ones when the latter is not feasible.