Transcript
UBM and US of Eye
Mohamed ELShafieAssistant lecturer of ophthalmology
Kafr ELShiekh university
Pathophysiology of Blunt Ocular Trauma
If a large object hits the eye, most of the impact is usually taken by the orbital margin.
If a small object hits the eye, theeye itself may take most of theimpact.
There are four main mechanisms:
1- Coup (injury at the same point)
2- Contrecoup (injury at the opposite point)
3- Equatorial expansion
4- Global repositioning
Mechanism of Blunt Ocular Trauma
Anterior segment
Posterior segment
Adnexa
Orbit
Location of Injury
Anterior Segment
Conjunctiva
Cornea
Iris & Ciliary body
Lens & Zonules
Effects on the Cornea
Blood stained cornea
Corneal Abrasion
Corneal Edema
Effects on the Iris and Ciliary Body
HyphemaAngle recessionIridodialysis
Traumatic mydriasis
Cyclodialysis Cleft
Effects on the Lens and Zonules
• Traumatic cataract
• Vossius' Ring
• Lens Subluxation
• Lens Dislocation
• Anterior Capsule Rupture
• Posterior Capsule Rupture
• PCIOL Dislocation
Posterior Segment
Vitreous
Retina
Choroid
Optic nerve
Effects on the Vitreous
Posterior vitreous detachment
• Vitreous hemorrhage
Effects on the Retina
Rhegmatogenous retinal detachment
• Commotio retinae
• Retinal Hge
• Retinal Tear without detachment
• Retinal Dialysis
Effect on the Optic Nerve
Optic nerve avulsion
Non invasive Out patient…
Ultrasonsogarphyin evaluation of a case with blunt trauma
*Difficult clinical examination.
* Uncooperative patient.
* To assess the extent of intraocular injuries.
Need for ultrasound
Orientations of the B-scan Probe
• Axial:Lesion in relation to lens &optic nerve .
•Transverse: Lateral extent, 6 clock hours .
•Longitudinal:AP extent,1 clock hour.
Ultrasound biomicrscopy
UBM uses high frequency ultrasound (50-100MHZ) to produce images of the eye with high resolution (50 um) with reduced depth of penetration (5mm).
Structural abnormalities
Guide to treatment
Follow up after treatment
A new method for gonioscopy and
quantitative angle measurement
Orientations of the UBM probe
• Transverse sectionLateral extent
• Radial section
Examination Technique of UBM:
• Patient is lying down in supine position
• Monitor is at comfortable height
• Hand controller is in accessible position.
• Eye cup of suitable size separate the two lids, filled with saline solution.
Examples from our cases by
B-scan Ultrasound
Male patient of 45 years old was exposed to blunt trauma 2 years ago .. Clinical
examination show traumatic cataract
B-scan US show rupture of posterior capsule which cant be detected by clinical
examination
A case with Vit. Hge that couldn't be detected clinically due to corneal oedema
A case with RD
Retinal break could be localized only by US
A case with PVD
Mobility of PVD is more than RD.
PVD becomes more prominent in higher gain settings
A case with retinal tear without detachment
A case with posterior lens dislocation
A case with PCIOL dislocation
A case with optic nerve avulsion
Retinal step sign from an edematous retina to bare sclera.
Examples from our cases by
UBM
25 years old man exposed to blunt trauma .. Clinically slit lamp showed corneal oedema,
which mask visaulization of the anterior segment
UBM examination showed subluxated lens with vitreous prolapsed in AC.
A case with iridodialysis
separation of the iris root from its attachment to the ciliary body
A cases with hyphema
A case with angle recession that couldn't be detected clinically
Tear in the ciliary body itself, between the circular and the longitudinal fibers
A case with cyclodialysis cleft
Separation of the ciliary body from the scleral spur resulting in cleft
A case with PCIOL dislocation
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