The diagnosis of narrow angle glaucoma is usually made on clinical examination using a gonioscopy lens.
This lens permits the examiner to see into the trabecular meshwork.
ULTRASOUND BIOMICROSCOPY (UBM)
A more sophisticated approach is to visualise the angle is using an ultrasound device.
An advantage of the UBM is that since it uses ultrasound energy, it can see structures behind the iris such as tumors and cysts which may the cause of the angle narrowing.
Further, conditions such as plateau iris which a variant of narrow angle can be more clearly seen using the UBM.
ANTERIOR SEGMENT (OCT)
Ocular Coherence Tomography (OCT) can be used not only to examine the retina but it can also be used to visualise the angle.
This in combination with the UBM and a clinical exam are used to diagnose narrow angles.