A review of the role of ultrasound biomicroscopy in glaucoma associated with rare diseases of the anterior segment

Abstract

Ultrasound biomicroscopy is a non-invasive imaging technique, which allows high-resolution evaluation of the anatomical features of the anterior segment of the eye regardless of optical media transparency. This technique provides diagnostically significant information in vivo for the cornea, anterior chamber, chamber angle, iris, posterior chamber, zonules, ciliary body, and lens, and is of great value in assessment of the mechanisms of glaucoma onset. The purpose of this paper is to review the use of ultrasound biomicroscopy in the diagnosis and management of rare diseases of the anterior segment such as mesodermal dysgenesis of the neural crest, iridocorneal endothelial syndrome, phakomatoses, and metabolic disorders.

Automatic Classification of Anterior Chamber Angle Using Ultrasound Biomicroscopy and Deep Learning

“…UBM, which was first designed by Pavlin et al,10 combines high-frequency ultrasound and computer image processing technology and is able to acquire high-resolution images of the anterior segment that provide valuable information about the cornea, anterior chamber, chamber angle, iris, ciliary body, zonules, and lens. Since its inception, it has become an important method that greatly assists the clinician in the diagnosis and management of angle closure and other subtypes of glaucoma 14. Currently, UBM is the most widely used method for the study of ACA regardless of optical media transparency 15…”

‘Ɛ’ sign: a clinical clue to the diagnosis of microspherophakia

“…The hallmark of this condition is visibility of the equator of the lens on pharmacological mydriasis and triad of shallow anterior chambers, lenticular myopia and angle-closure glaucoma [2]. Additional criteria on adjunctive investigative modalities like Ultrasound Biomicroscopy (UBM) [3], such as zonular elongation (anterior zonular fibres >2 vs <1 mm normally), increased lens sphericity and ciliary body flattening in areas with missing zonules, and documentation of very high lens thickness on LensStar, IOL master, USG etc., may help confirm the diagnosis.…”

Cornea and anterior eye assessment with slit lamp biomicroscopy, specular microscopy, confocal microscopy, and ultrasound biomicroscopy

“…4 ]. [ 43 ] Commercially available ultrasound biomicroscopes employ high-frequency ultrasound transducers (between 25 and 50 MHz) with an immersion technique, to obtain high-frequency B-scan ultrasonography images to a depth between 4 and 5 mm with lateral resolution of approximately 25 μm and 50 μm. Many devices include A-scan ultrasonography to measure the eye axial length (from the cornea to the retina) and explore posterior segment of the eye.…”

“…Moreover, UBM has been used in evaluating corneal dystrophies, corneal scars, cysts, excimer laser photokeratectomy and LASIK procedures, to explore intraocular lens (IOL) implants, glaucoma diagnosis (open-angle glaucoma, primary angle closure glaucoma included plateau iris syndrome, pigmentary glaucoma, and pupillary block glaucoma, pseudoexfoliation syndrome), explore anterior and posterior segment tumors (providing valuable information on the extension of pigmented lesions or malignant melanoma from the iris to the ciliary body), and other rare eye diseases (such as mesodermal dysgenesis of the neural crest, ICE syndrome, phakomatoses, and metabolic disorders). [ 43 ] UBM has been used in IOLs patient assessment (nonsutured and sutured fixation of IOL) measuring anterior chamber depth, sulcus-to-sulcus diameter, capsular bag thickness, capsular bag diameter, ciliary ring diameter, ciliary process-capsular bag distance, ciliary apex-capsular bag plane, IOL tilting, haptic location, iris-IOL contact, vitreous incarceration, and conducting a scleral fixation assessment. [ 44 45 ]…”