By DR MARYAM FARGHADANI RADIOLOGIST

Sonography of the orbit

1• Opacity of light-conducting media, making direct vision by ophthalmoscopy difficult 2• Suspected intraocular tumour-solid lesions are readily diagnosed, sited and measured by ultrasound 3• Differentiation of serous and solid retinal detachment; a detachment may conceal a tumour-the subretinal area is clearly demonstrated by ultrasound

4• Examination of the vitreous

5• Localisation of foreign bodies 6• Ocular measurements (biometry by calibrated A-scan) 7• Proptosis (CT and MRI are usually more helpful) 8• Doppler investigation of orbital vascular disease and tumours.

Indications

Patients with opaque light-conducting media form the majority of referrals, especially those with cataracts and haemorrhages. It is not necessary to scan every patient with a cataract, but if other symptoms develop, for example inflammation, pain, rapidly worsening vision or the development of glaucoma, then a scan must be performed to determine any coexistent pathology. When vitreoretinal surgery is contemplated, ultrasound assessment of the globe is mandatory. The information required includes: • The state of the vitreous • The position and extent of any intraocular lesion visible by ultrasound • The condition of the retina, and particularly the macula • The mobility of the contents of the globe, which has a direct influence on operability • The relation between the vitreous and retina, mapping out any vitreoretinal adhesions.

Retinal detachmentAcquired retinoschisisDisciform lesionsDrusen(hyalin bodies)

RETINA

Retinal detachment

Retinal tear

Retinal detachment and transvitreal membrane

Disciform lesions

retinoschisis

Drusen

Chroidal detachment

Subchroidal hemorrhage

Persistant hyperplastic primary vitreosVitreous hemorrhageAsteroid hyalosis

Posterior vitreous detachment

vitreous

PHPV

Dense vitreous haemorrhage arranging into thick mobilefibrinous membranes

Subvitreal haemorrhage in a diabetic

Asteroid hyalosis

PVD, eye deviated to right and left side

Ocular tumors

45-year-old woman with ciliary body melanoma. Sonogram shows tumor is large and round, which is common for

melanoma.

Color Doppler sonogram shows blood vessels encircling and penetrating tumor.

62-year-old man with melanoma arising from ciliary body, which is small and buttonlike. Small melanoma of ciliary body can be missed because of its small size and location if funduscopy is performed without depressing sclera externally.

Complications of melanoma in 69-year-old woman with diminished brightness of vision. Vitreous hemorrhage, seen as low-level echoes filling vitreous body (V), completely obscures direct view of tumor (arrow) by funduscopy.

Complications of melanoma in 42-year-old man with severe loss of vision in one eye. Location of melanoma (large arrow) on and adjacent to optic disk (small arrows) may prevent radiation

treatment and could necessitate enucleation of eye.

conclusion

Sonography of the eye shows a variety of diseases with remarkable clarity. The technique is more cost-efficient than other diagnostic techniques and is well tolerated by the patient. We have experienced no limitations and have received no complaints from patients. We do not advocate the routine use of sonography in the asymptomatic eye, but it may serve as a useful extension of the initial investigation of the symptomatic patient.

Thank you for your attention