الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
Ultrasound Biomicroscopy (UBM) is a new imaging at near microscopic resolution in living patient This technique allows imaging of the structural details of the anterior chamber. provides exceptionally detailed two dimensional gray scale images of the bulbar conjunctiva, cornea, anterior sclera, aqueous humour, anterior chamber , angle structure , uveal and ectodermal components of the ciliary body, anterior layers of the lens, zonules and anterior vitreous.
The canalicular disorders evaluated in five subjects: acquired common canalicular obstruction ,congenital common canalicular obstruction ,partial common canalicular obstruction from a posteriorly located common canalicular-sac junction without stenosis ,silastic tube within the canalicular system and silicon plug within the punctum. It was hardly possible to find the lacrimal canaliculi. Using ultrasound probes with a higher frequency, e.g. 20 to 50 MHz, the delineation could be improved, especially that of canaliculi.High resolution ultrasound is an uncomplicated method to demonstrate a chronic cancaliculitis.
Lacrimal drainage system (LDS) with silicon tube after dacryocystorhinostomy (DCR) was also evaluated, showing the osteotomy opening as a lack of bony hyper-reflectivity, the silastic tube and turbulence of the fluid within the sac.
UBM used in diagnosis of dacryocystitis that included a few months duration,longstanding of more than 2 years, chronic forms with a remarkably distended sac before and after pressure on the sac to evaluate regurge, chronic with LS fistula ,chronic associated with dacryolith and chronic associated with a pyogenic granuloma mass as well as mucocoele LS tumours could be missed clinically unless dacryocystography (DCG) is considered, with hazards of radiation so ubm used without hazards of radiation.
UBM used to distinguish the normal canaliculus from the findings after plug placement. The echograms can vary from one plug type to another. Highly reflective structures were found after the placement of silicone intracanalicular plugs, e.g. the Herrick plug. In contrast, the ultrasonic image of acrylic polymer intracanalicular plugs, e.g. the smart plug, showed homogenous small reflective inner structures.
UBM non-invasive and safe investigative tool. UBM enable us to image the canalicular system in substantial. detail, Permitting detection of anatomical abnormalities, obstructions,plugs, examination of surrounding tissues and LS distal to the site of complete obstruction.
UBM has been reported in the evaluation of the normal proximal canalicular system in a cadaver model, canaliculitis, estimation of canalicular dilation after balloon catheter and retained intracanalicular plugs .Another advantage of UBM is the ability to assess the variability in the position of the canalicular-sac junction.
The UBM is a valuable tool for the assessment of both normal and diseased LDS. Despite its inability to evaluate the bony NLD, the UBM is able to evaluate LDS distal to the site of obstruction.
UBM used to differniate space occuping lesion of the superotemporal conjunctival fornix orbital fat prolapse, subconjunctival lipodermoid (dermolipoma), prolapsed lacrimal gland, and lacrimal gland ductal cyst (dacryops).