الفهرس | Only 14 pages are availabe for public view |
Abstract Ultrasound biomicroscopy (UBM) is a new imaging technique that uses high frequency ultrasound (50-100 MHz), providing resolution ranging from 20-60 micrometers with a depth of penetration approximately 4mm. There are many applications to this imaging method including visualization, localization and documentation of the anterior segment anatomy and pathology. UBM in diagnosis of trauma shows disruption of normal appearance of intra ocular structures. UBM can be used to detect the presence of cyclodialysis and determine its extent irrespective of optic media condition, as UBM appearance of traumatic cyclodialysis is typical and diagnostic. UBM provides clinically useful information in the detection or delineation of anterior segment foreign bodies, and it is recommended as the preferred initial imaging step in searching for an occult foreign body in the absence of an obvious rupture of the globe. Also UBM is useful to evaluate the tomographic features of the disrupted trabecular meshwork, iridodialysis and angle recession. UBM combined with slitlamp biomicroscopy is useful in estimating the extent of an intracorneal haematoma and corneal blood staining, helping in deciding whether surgical treatment is necessary or not. Anterior vitreous haemorrhage can also be imaged by UBM. UBM can also be used in the diagnosis of epithelial downgrowth, anterior segment implantation, traumatic myopia,zonular abnormalities, bread and detachment of ciliary epithelium. UBM, with it’s few technical difficulties, should not be used as an additional examination technique in the evaluation of traumatized eyes, but rather as the technique of choice in different media opacity conditions, eg., hypopyon or hyphaema. It is also the best method when resolution required for detection of certain lesions, eg., IOFBs is not available by other methods eg., conventional U/S. It is also the method of choice in detecting lesions in hidden areas, eg., foreign body in the anterior chamber. However, UBM should never be used in cases of trauma with opened globe. |