Primary Angle-Closure Glaucoma Công cụ chẩn đoán

Laboratory Tests and Ancillaries

Ocular Biometry  

Ocular biometry may be considered in angle closure to measure axial length and ocular lens power prior to cataract surgery. This is useful to identify nanophthalmos (short axial length or <20 mm) prior to incisional surgery to avoid complications such as shallowing of the anterior chamber and aqueous misdirection.  

Provocative Tests  

Provocative tests provide little additional information since they cannot exclude the possibility of angle closure even if the test is negative. This may trigger an acute angle-closure attack.

Imaging

Anterior Segment Imaging  

Examples of anterior segment imaging are anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy.  

Anterior segment imaging may be used only in cases that are most difficult to interpret because of its limited availability and costs. This should be considered when assessment of angle anatomy is difficult with gonioscopy. AS-OCT can assess angle qualitatively and quantitatively but with some limitations. This is useful in elucidating plateau iris. Ultrasound biomicroscopy can determine the cause of plateau iris, plateau iris configuration, and ciliary body compared to AS-OCT.