My first Eye Ultrasound was back in 1986 To check for foreign body.Then in Saudi Arabia, Al Hofuf hospital with the Ophthalmology department. I was trained to do the A AND B Modes. and did Eye sonography 2 days a week.14 patients a day. The Ophthalmologist was doing the report and not the radiologist.
An eye and orbit ultrasound is a test that uses high-frequency sound waves to get measurements and produce detailed images of your eye and eye orbit.
The orbit is the socket in your skull in which your eye sits.
Sometimes called eye studies, the procedure is usually performed by an ophthalmologist (a doctor specializing in diagnosing and treating eye disorders and diseases). Eye studies can also be performed by a technician in an office, outpatient center, or hospital.
During the test, a transducer is placed on the eyelid or the front surface of your eye. Because ultrasound can show details about the cornea and the structure of your eyes, eye studies are very useful in the diagnosis and treatment of a variety of eye conditions. Use gel pad for eye protection.
Ultrasound provides a much more detailed view of the inside of your eye than is possible during a routine eye exam. Your eye doctor may order eye studies if you are experiencing unexplained problems with your eyes or if you have recently sustained an injury or trauma to the eye area.
This procedure is helpful in identifying tumors, neoplasms (abnormal growths), foreign substances, detachment of the retina, and in diagnosing diseases of the eye. For example, your doctor can use this procedure to measure the thickness and extent of a cancerous tumor and to assess treatment options.
Eye and orbit ultrasound also can be used to help diagnose and/or monitor:
- glaucoma (a progressive disease that can lead to vision loss)
- cataracts (cloudy areas in the lens)
- lens implants (plastic lenses implanted in the eye after the natural lens has been removed, usually due to cataracts).
The ultrasound study of the eye can be performed in a hospital, an outpatient center, or in an ophthalmologist’s office. There are two parts to an eye and orbit ultrasound. The A-scan ultrasound is used to take measurements of the eye. The B-scan allows the doctor to see clearly into the back of the eye.
There is no preparation required for an eye and orbit ultrasound. You will be able to drive after the procedure, but you can arrange alternate transportation if you are concerned about your ability to see clearly. The procedure will take 30 minutes to complete.
There is no pain associated with ultrasound, although anesthetic drops will be used to numb your eye and minimize discomfort. Your eyes will not be dilated. The transducer will then be placed against the front surface of your eye. As the high-frequency sound waves travel through your eye, pictures of the structure of your eye are formed.
A-Scan
The A-scan is used to measure the eye. This is useful in determining the correct lens implant for cataract surgery.
While sitting upright in a chair, you will place your chin on a chin rest and look straight ahead. A probe that has been oiled will be placed against the front of your eye as it is scanned.
An A-scan can also be performed while you are lying down. In that case, a fluid-filled cup (water bath) is placed against the surface of your eye as it is scanned.
B-Scan
The B-scan helps the doctor see the space behind the eye that can’t be seen otherwise. Cataracts and some other conditions make it difficult to see the back of the eye. The B-scan also aids in the diagnosis of tumors, retinal detachment, and other conditions.
For the B-scan, a gel will be put on the skin of your eyelids. You will be in a seated position with your eyes closed and will be directed to look in many directions as the probe is placed against your eyelids.
There are no serious risks associated with the eye ultrasound.
To avoid scratching your cornea, you are advised not to rub your numbed eyes following the procedure until the anesthetic has completely worn off. This should take between 15 and 30 minutes. Your vision may also be temporarily blurred during this time. You should be able to drive within a half hour, but you may feel more comfortable arranging for someone else to drive.
Retinal detachment
Some conditions that may be revealed by the B-scan include:
- foreign bodies in the eye
- cysts
- swelling
- detachment of the retina
- damaged tissue or injury to the eye socket (orbit)
- vitreous hemorrhage (bleeding into the clear gel, called vitreous, that fills the back of the eye)
- cancer of the retina, under the retina, or in other parts of the eye
Your ophthalmologist will review the results with you.
I. Introduction and Indications
Ocular emergencies account for 3% of all emergency department visits. Ocular symptoms remain some of the most challanging to evaluate in a busy emergency department. Ophthalmologic consultation is not available in all settings, which can potentially lead to misdiagnosis and treatment delays. The evaluation of ocular emergencies can be limited by lack of sophisticated tools and training.
A hyperechoic foreign body in the eye. Note the bright echogenic reverberation artifact
Direct visualization of intraocular structures is difficult or impossible when the eye lids are swollen shut after injury. Lens opacification and hyphema can also block the posterior view of the chamber. The recent spread of ultrasound technology and adaptation of it at the bedside by emergency physicians has led to exploration of a number of applications. Ocular ultrasonography is a relatively new application in emergency medicine.
In 2002, Blaivas et al. published the first series of ED patients presenting with ocular symptoms who were evaluated by bedside emergency department ultrasonography. The ability of ultrasound to evaluate the eye and the adjacent structures in a rapid and noninvasive manner is of tremendous value in the setting of a busy emergency department. ED ultrasound provides a quick, accurate, well-tolerated, noninvasive tool for evaluating potentially vision-threatening conditions at the bedside. The need for pupillary dilatation and direct ophthalmoscopy are obviated by the use of bedside ultrasound. Ocular ultrasound can expedite the diagnosis and management of several ocular emergencies including globe perforation, retrobulbar hematoma, retinal detachment, lens subluxation, vitreous hemorrhage, and intraocular foreign body.
Retinal Detachment.,
Choroidal Detachment
We do us for many reasons
1. Decreased vision/loss of vision
2. Suspected foreign body
3. Ocular pain
4. Eye trauma
5. Head injury
A high-resolution 7.5- 10-MHz or higher linear array ultrasound transducer is used to perform an ocular examination. Emergency ocular ultrasonography is performed using a closed-eye technique. A large amount of standard water-soluble ultrasound transmission gel should be applied to the patient’s closed eyelid so that the transducer doesn’t have to touch the eyelid. Ultrasound gel is not detrimental to eye. The globe should be scanned in both sagittal and transverse planes. Both eyes should be scanned through closed eyelids. The patient is asked to look straight ahead with eyes closed, but without clenching the eyelids. Depth should be adjusted so that the image of the eye fills the screen. Gain should be adjusted to achieve acceptable imaging. Since the eye is a fluid-filled structure, it provides a perfect acoustic window, producing images with excellent detail. The normal eye appears as a circular hypoechoic structure. The cornea is seen as a thin hypoechoic layer parallel to the eyelid. The anterior chamber is filled with anechoic fluid and is bordered by the cornea, iris and anterior reflection of the lens capsule. The iris and ciliary body are seen as echogenic linear structures extending from the peripheral globe towards lens. The normal lens is anechoic. The normal vitreous chamber is filled with anechoic fluid. Vitreous is relatively echolucent in a young healthy eye. Sonographically, the normal retina cannot be differentiated from the other choroidal layers. The evaluation of the retrobulbar area includes optic nerve, extraocular muscles and bony orbit. The optic nerve is visible posteriorly as a hypoechoic linear region radiating away from globe.
Globe Rupture
Bedside ultrasound has revolutionized the management of a traumatized eye. Evaluation of patients with ocular trauma by ultrasound is of particular value when abnormalities like corneal edema, hyphema, vitreous hemorrhage or cataract make direct visualization of the ocular contents difficult. Traumatic globe rupture is a major ophthalmologic emergency and almost always requires surgical intervention. Ultrasound findings of globe rupture include decrease in the size of the globe, anterior chamber collapse and buckling of the sclera.
Intraocular Foreign Body
The utility of ultrasonography in detecting and localizing radiolucent orbital foreign bodies and its clear superiority in the localization of foreign bodies has been clearly established. Intraocular foreign bodies are identified by their bright echogenic acoustic profile and either shadowing or reverberation artifacts seen in the usually echolucent vitreous. Ultrasound patterns of shadowing and comet tails may help differentiate foreign body materials.
Retinal Detachment
Retinal detachment can be difficult to detect on physical examination, especially when the detachment is small. On occasion retinal tears are accompanied by vitreous hemorrhages. A retinal detachment will be seen as a hyperechoic undulating membrane in the posterior to lateral globe (Figure 5). In patients with total retinal detachments, the typically folded surface attaches to the ora serrata anteriorly and the optic nerve posteriorly.
kissing view for Choroidal detachments.
CHOROIDAL DETACHMENT
evated Intracranial Pressure – Optic Nerve Sheath Measurement
The evaluation of the optic nerve sheath diameter is a simple non-invasive procedure, which is a useful tool in the assessment of elevated intracranial pressure. Ocular ultrasound for evidence of increased intracranial pressure has been described in cadavers. Recently, Blaivas et al. described its use among adult patients in the emergency department with suspected elevated intracranial pressure (EICP).(2) Patients with altered level of consciousness may be suffering from increased intracranial pressure from a variety of causes. EICP may be present in emergency department patients with head injury and also in those with spontaneous intracranial bleed. Physical examination has significant limitations if the patient is unconscious, or intubated and paralyzed. Papilledema from EICP may be delayed after ICP elevation, by up to several hours. A rapid, bedside and noninvasive means of detecting EICP is desirable when conventional imaging methods are unavailable. The eyes often reflect disease states elsewhere in the body. The optic nerve attaches to the globe posteriorly and is wrapped in a sheath that contains fluid. The optic nerve sheath is contiguous with the dura mater and has a trabeculated arachnoid space through which cerebrospinal fluid slowly percolates. The relationship between the optic nerve sheath diameter (ONSD) and ICP has been well established. Evaluation of the optic nerve sheath diameter (ONSD) can detect EICP. On ultrasound a normal optic nerve sheath measures up to 5.0 mm in diameter. The ONSD is measured 3 mm posterior to the globe for both eyes. A position of 3 mm behind the globe is recommended because the ultrasound contrast is greatest, the results are more reproducible (Figure 6). Two measurements are averaged. An average ONSD greater than 5 mm is considered abnormal and elevated intracranial pressure should be suspected.
Vitreous Hemorrhage
Vitreous hemorrhage can interfere with vision, and if it is large can cause blindness. It appears as echogenic material in the posterior chamber. The sonographic appearance of vitreous hemorrhage depends on its age and severity. Fresh mild hemorrhages appear as small dots or linear areas of areas of low reflective mobile vitreous opacities, whereas in more severe and older hemorrhages, blood organizes and forms membranes. Vitreous hemorrhages may also layer inferiorly due to gravitational forces.
