Introduction:
Imaging techniques have facilitated radiodiagnosis in unique ways. The clinical findings must be supported with apt imaging outcomes to establish a confirmatory diagnosis. Ultrasonography is the most preferred imaging technique due to its simple and non-invasive technique. It has varied applications throughout the body. Ultrasound utilizes high-frequency sound waves to capture images of body parts and organs. It is relatively straightforward, cost-effective, and, most importantly, helps with real-time imaging of the body parts. Considering its relative ease of working, ultrasound has been applied efficiently in various branches of medicine like cardiology, reproductive medicine, neurology, and others. However, one of the unique applications is in ophthalmology, also known as eye orbit ultrasound.
What Are Eye and Orbit Ultrasounds?
Sonographic examination of the eye or orbit is known as eye orbit ultrasound. It is also known by alternative names such as eye orbit echography, ocular ultrasonography, or orbital ultrasonography. Eye orbit ultrasound uses sound waves to create detailed images of the eye and other vital structures within the orbit. It can help evaluate the size and structure of the eye and the orbit. In addition, a Doppler ultrasound can be highly beneficial in assessing and evaluating the blood flow throughout the orbit.
Where Is Eye and Orbit Ultrasound Indicated?
A routine eye examination involves visualizing the eye and other orbital structures through an ophthalmoscope. However, in certain conditions, direct visualization may not be sufficient or may be obscured by certain pathologies. In such a situation, it is imperative to use an imaging modality such as ultrasound to get a more detailed view than a conventional eye examination. Therefore, it is routinely indicated in the following conditions:
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Unexplained vision problems or problems with the eyes.
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Orbital trauma or injury.
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To diagnose retinal detachment.
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Presence of foreign bodies in the eyes
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Diagnose cysts or neoplasms in the eye or orbit.
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To diagnose or monitor conditions like glaucoma (a progressive condition resulting in vision loss) or cataract (blurred vision due to cloudy lens).
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Post cataract surgery to monitor the condition of the implanted lens.
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To assess the severity of the eye socket damage in case of trauma or injury.
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Swelling or cysts.
How Should Patients Prepare for an Eye and Orbit Ultrasound?
Eye orbit ultrasound is a relatively simple and painless procedure and does not require special patient instructions. It is an outpatient procedure, and the entire procedure may take roughly 15 to 30 minutes.
How Is the Procedure Done?
The patient is assisted to the procedure room and made to sit comfortably. Though there is no pain involved with this procedure, anesthetic drops may be used to numb the eye. This is done to reduce discomfort. The pupils need not be dilated, as is done for a routine eye examination. However, there is still a possibility of blurred vision for 30 to 40 minutes after the procedure. The ultrasound unit comprises a small hand-held device known as a transducer that emits high-frequency sound waves into the body. This transducer is placed on the front surface of the upper eyelid. Upon hitting the internal structures, these sound waves tend to bounce back. The transducer then captures these reflecting sound waves and then processes them as images in a computer based on the time it takes to reflect. The images may be visualized on a screen in two-dimensional or three-dimensional form. Eye orbit ultrasound may be of two types:
A-scan
A-scan is used to evaluate eye measurements. It is primarily indicated in cataract surgery to determine the correct lens size that needs to be implanted during cataract surgery. The patient is advised to sit on a chair with the chin placed on a chin rest. The patient will be asked to look ahead, and a tiny probe will be placed on the eye's front surface. If the test is done while the patient is lying on their back, a fluid-filled or water-filled cup may be placed against the eye while scanning.
B-scan
This scan helps to take images of the inside and back of the eye. Conditions like cataracts, cysts, and tumors may provide less access to view the rear side of the eye. During this scan, the patient will be seated on a chair and asked to close their eye. Next, a gel will be applied to the eyelids, and the transducer may be moved around and back and forth over the eye. The patient may also be asked to rotate their eyeballs in various directions.
What Are the Instructions After the Procedure?
Patients are requested not to self-drive home since there would be some blurring of the eye. Instead, they are asked to bring some help to assist them back home. Once home, the patient can resume their routine activities. They are also advised not to scratch their eye till the effect of anesthesia wears off.
How Are the Results Interpreted?
Normal Results:
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A-scan:
When the measurements of the eye are within the normal range.
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B-scan:
When the morphologic and anatomical structure of the eye and orbit appear normal.
Abnormal Results:
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A-scan:
Abnormal measurements could indicate the presence of a neoplasm, cyst, or foreign body.
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B-scan:
Abnormal B-scan results are indicative of structural abnormalities like
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Swelling or inflammation.
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Cysts.
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Cancers like retinoblastoma or melanoma.
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Hemorrhage or bleeding.
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Trauma or injury damaging the ocular tissues.
What Are the Benefits of This Procedure?
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Non-invasive.
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Well tolerated by the patients.
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Cost-effective.
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Helps in quantitative and structural analysis of the eye and associated orbital structures.
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Nil recovery time as it is a non-invasive procedure.
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Quick, easy, and painless.
What Are the Risks Associated With the Procedure?
Considering this procedure involves local anesthetic, patients will be advised not to scratch or irritate their eye for 15 to 30 minutes after the procedure or till the anesthetic effect wears off. Or else it could result in redness or minor corneal abrasions.
Conclusion:
Ocular ultrasound is painless and, instead, a simple diagnostic procedure. It helps identify pathologies or conditions that could not be diagnosed in a routine eye examination. Unresolved and unexplained ophthalmological diseases could be well explained and promptly managed using an eye orbit ultrasound.
