UBM & Angle Imaging

Ultrasound Biomicroscopy is a non-invasive technique used for evaluating what 4 things

- narrow chamber angles

- angle closure glaucoma

- pathology of the ciliary body

- space occupying lesions (cysts)

List the 4 standard measurement that are given in a UBM

- angle opening distance (AOD)

'- angle recess area (ARA)

- anterior chamber depth (ACD)

- lens vault

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What is the AOD measurement

angle opening distance:

the perpendicular distance between the TM at a point 500microns anterior to the scleral spur and the iris

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What is the ARA measurement

angle recess area:

triangular area bound between the AOD line and the angle recess

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What is the ACD measurement

anterior chamber depth:

distance between the central corneal endothelium and the anterior surface of the lens

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What is the Lens Vault measurement

the distance of the lens located anterior to the perpendicular line between the scleral spurs

* picture on slide 35 *

What is the Corneal Thickness measurement

distance between the anterior surface of the epithelium and posterior surface of the endothelium

What is the Epithelial Thickness measurement

distance below the tear film and above Bowman's layer

Give the 4 major benefits of UBM

- very detailed anatomic views

- px is dark adapted

- assist in dx of anterior segment tumors and cysts (images behind the iris)

- assist in dx of primary angle closure glaucoma

UMB is particularly useful to confirm the presence of which iris configuration

iris plateau

(T/F) Iridectory or laser iridotometry are effective therapies in Plateau Iris Syndrome

FALSE

these px require an Iridoplasty... this involved holes lasered all around the periphery and then when the body attempts to heal itself and forms scar tissue - the scar tissue pulls and tightens the iris so it no longer rests in a plateau postions

List the 6 standard measurement that are given with AS-OCT

- angle opening distance (AOD)

'- angle recess area (ARA)

- anterior chamber depth (ACD)

- lens vault

- corneal thickness

- epithelial thickness

What are the 3 main limitations of AS-OCT

- cannot penetrate the iris

- uses light to obtain the image so angle anatomy will be altered

- cannot define scleral spur (25% of the time)... this can make some of the measurements that depend on scleral spur location to be a inaccurate

(UBM/AS-OCT) gives more information about anything posterior to the iris

UBM

(UBM/AS-OCT) has been around longer and therefore has more clinical trials to support it

UBM

(UBM/AS-OCT) is more involved and more unique for the px to have to sit through

UBM

* not used to things like this in their regular eye exam *

(UBM/AS-OCT) gives higher resolution images of the iris and angle

AS-OCT