Norm of Eye and Orbit Ultrasonography (Eye and Orbit Echograms, Eye and Orbit Sonograms)
Negative for foreign body, cyst, inflammation, tumor, retinal detachment, or optic nerve atrophy. Orbit is of proper size, shape, and concavity.
Usage of Eye and Orbit Ultrasonography (Eye and Orbit Echograms, Eye and Orbit Sonograms)
Alternative to direct ophthalmoscopic visualization of the interior of the eye when cataract, fundal opacity, or vitreous hemorrhage is present; detection of intraocular foreign body or tumor; detection of retrobulbar optic nerve, optic nerve atrophy, or optic nerve tumor; differentiation of intraocular melanoma; eye measurement before lens implant; and evaluation of fundal abnormalities, intactness of retina, and the vitreous humor.
Description of Eye and Orbit Ultrasonography (Eye and Orbit Echograms, Eye and Orbit Sonograms)
Evaluation of the eye and orbit by the creation of an oscilloscopic picture from the echoes of high-frequency sound waves passing over the eye and eyelid (acoustic imaging). The time required for the ultrasonic beam to be reflected back to the transducer from differing densities of tissue is converted by a computer to an electrical impulse displayed on an oscilloscopic screen to create both a linear waveform and a two-dimensional dot-pattern picture of the structures. The B-scan mode is used to evaluate the optic disc, and the A-scan mode is used to evaluate optic nerve disease. Water immersion of the eye may also be used with the eye ultrasonogram to enhance images of the anterior part of the globe. The immersion of the transducer in water lifts it away from the eye, while still preventing air from obscuring the image. The transducer provides the best picture when it is at least 5–8 mm away from the structures being imaged. A newer method, ultrasound biomicroscopy, is able to provide even better images of the relationship of the structures of the anterior globe of the eye than conventional immersion ultrasonography.
Professional Considerations of Eye and Orbit Ultrasonography (Eye and Orbit Echograms, Eye and Orbit Sonograms)
Consent form NOT required.
- A sedative or general anesthetic may be used for children being evaluated for retinoblastoma or other purposes. The child should fast from food and fluids for 4 hours if general anesthesia will be used.
- Remove metal objects such as eyeglasses or jewelry from the client's head and neck.
- Obtain anesthetic eyedrops and conductive gel. If water immersion is to be performed, obtain an ocular drape and 0.9% sterile saline.
- The client is positioned supine in bed or on a procedure table.
- After anesthetic eyedrops are administered, a transducer coated with conductive gel is slowly passed over a clear, methylcellulose eye form applied to the eye to form an airtight seal. The resulting waveform provides eye measurements and helps delineate the presence of abnormal tissue or structure.
- The eye cup is removed and the eyelid closed. The gel-coated transducer is then slowly passed over the eyelid. A two-dimensional image of the eye and orbit is displayed on the oscilloscope.
- Water immersion (sometimes performed):
- a. A waterproof drape is fastened around the orbit.
- b. After anesthetic drops are instilled, the eyelid is retracted, and the eye is flooded with warm, sterile 0.9% saline.
- c. The transducer is immersed into the water and moved slowly across the eye.
- d. The client may be asked to move the eye in specific directions.
- e. The water is then drained and the drape removed.
- The procedure takes less than 30 minutes. Permanent photographs of the oscilloscopic recordings are made.
- Remove conductive gel from the eyelid(s) after the anesthetic effects have worn off (to prevent corneal damage).
- If general anesthesia was administered, monitor vital signs every 15 minutes × 4, then every 30 minutes × 2, and then hourly × 4. Additional monitoring typically includes continuous ECG monitoring and pulse oximetry, with continual assessments (every 5–15 minutes) of airway, vital signs, and neurologic status until the client is lying quietly awake, is breathing independently, and responds appropriately to commands spoken in a normal tone.
Client and Family Teaching
- The procedure is noninvasive, painless, and poses no risk; it is important for you to relax the eyelid during the procedure.
- You may hear an echo that sounds like repetitious humming or a musical note as the eye structures reflect the ultrasonic beam.
- Avoid rubbing your eyes until the anesthetic effects have worn off (about ½ hour). Infants or small children may need to be restrained during this time.
Factors That Affect Results
- None found.
- None found.