Eye ultrasound: indications, purpose and procedure of an ocular ultrasound

Medically reviewed: 16, December 2023

Read Time:8 Minute

Ultrasound examination of the eye: methods, indications, contraindications and results

Ultrasound examination of the eye is a diagnostic method that allows you to visualize the structures of the eye and its periorbital region using high-frequency sound waves. Ultrasound of the eye can be used to detect various diseases and injuries of the eye, as well as to measure its parameters.

Ultrasound examination of the eye is a safe, painless and inexpensive method that can be performed on an outpatient basis. In this article we will look at the main methods, indications, contraindications and results of ultrasound examination of the eye.

Ultrasound examination methods of the eye

There are two main methods of ultrasound examination of the eye: A-scan and B-scan. These methods can be used individually or in combination, depending on the purpose of the study.

Ocular ultrasound with an A-scan

An ultrasound of an eye in A-scan mode allows one-dimensional image of eye structures to be obtained. A-scan is used to measure various anatomical parameters of the eyeball structures (ultrasonic eye biometry) and as a review ultrasound.

A-scan is an ultrasound examination of the eye that measures the length and thickness of various structures of the eye, such as the cornea, lens, vitreous and retina. An A-scan also allows you to determine the depth and size of various formations in the eye, such as tumors, hemorrhages, foreign bodies and detachments.

A-scan is based on recording the travel time and intensity of reflected ultrasonic waves from various boundaries between the structures of the eye. The result of an A-scan is a one-dimensional graph on which peaks corresponding to reflections from the structures of the eye are marked.

A-scanning is often used to determine the required power of an artificial lens during cataract surgery, as well as for the diagnosis and differential diagnosis of various eye diseases.

What A-scan is used for:

  • A-scan is aimed at detecting foreign bodies of the eye;
  • determination of the localization and size of neoplasms of various parts of the eye, monitoring the dynamics of their development;
  • diagnosis of the prevalence and height of detachment of the mesh and vascular membranes of the eye;
  • detection of opacities, destructive foci, blood clots in the vitreous with the recognition of the degree of their mobility and density.

Eye and orbit ultrasound with a B-scan

B-scan is an ultrasound examination of the eye that provides a two-dimensional image of the structures of the eye and its periorbital region. B-scanning also allows you to evaluate the mobility and echogenicity of various structures and formations in the eye. B-scanning is based on recording the intensity of reflected ultrasonic waves from various points of the eye, which are converted into the brightness of pixels on the screen.

The result of a B-scan is a two-dimensional image in which different structures of the eye have different brightness and contrast. B-scanning is often used to visualize the posterior parts of the eye, which are not accessible for examination using an ophthalmoscope or biomicroscope, as well as for the diagnosis and differential diagnosis of various eye diseases.

During the B-scan, the received echoes reflected from the anatomical structures of the eye are converted into a two-dimensional image, thus forming a picture of the “ultrasonic cut”. This method of ultrasound is more informative and sensitive in detecting various pathological processes of the orbit, but is less accurate in comparison with A-scanning.

It allows you to determine the location, shape and size, the relationship with a number of located structures, as well as the acoustic density of the pathological focus (tumor, infiltrate, foreign body, opacity, foci of destruction, etc.).

Eye ultrasound with an AB-scan

The ultrasound of the eye in the AB-scan mode makes it possible to conduct a more complex ultrasound of the eye, which allows you to overcome the limitations of individual A and B scans and combines the advantages of both these techniques.

Modern AB-scanners give a three-dimensional image of the structure of the eye, so that it is possible to determine not only the linear, but also the volume characteristics of the objects under study.

The ultrasound of the eye in the form of AB scanning has found application primarily in the impossibility of conducting an ophthalmoscope due to the opacity of the refractive media of the eye. With the transparency of the eye media, AB scanning is used in the diagnosis of retinal detachment, to measure biometric parameters, to determine the dynamics of the tumor process.

Indications for ultrasound examination of the eye

An ultrasound examination of the eye may be prescribed by an ophthalmologist in cases where it is necessary to obtain additional information about the condition of the eye and its periorbital area. Some of the main indications for ultrasound examination of the eye:

Impossibility or difficulty in examining the eye

Ultrasound examination of the eye may be necessary if examination of the eye with an ophthalmoscope or biomicroscope is impossible or difficult due to obstructions such as scars, hemorrhages, cataracts, pus or corneal trauma, or due to opacity of the eye media. , such as the vitreous body, lens or retina.

Ultrasound examination of the eye allows you to penetrate these obstacles and visualize the posterior parts of the eye, as well as determine the reason for the impossibility or difficulty of examining the eye.

Suspected presence of masses in the eye or its periorbital area

Ultrasound examination of the eye may be necessary if there is a suspicion of the presence of masses in the eye or its periorbital area, such as tumors, cysts, foreign bodies, abscesses, hematomas, or detachments. Ultrasound examination of the eye allows one to determine the location, size, shape, structure, mobility and echogenicity of formations, as well as their relationship to neighboring structures of the eye.

Ultrasound examination of the eye also helps in the differential diagnosis of various formations in the eye or its periorbital region.

Suspected damage to the eye or periorbital area

Ultrasound examination of the eye may be necessary if there is suspicion of damage to the eye or periorbital area due to trauma, inflammation, infection, surgery, or other causes.

Ultrasound examination of the eye allows us to detect the presence and degree of damage to various structures of the eye, such as the cornea, iris, lens, vitreous body, retina, optic nerve and others. Ultrasound examination of the eye can also determine the cause of eye damage, such as trauma, inflammation, infection, tumor, detachment or other pathology. Ultrasound examination of the eye helps in choosing the optimal treatment method and monitoring its effectiveness.

Contraindications to ultrasound examination of the eye

Ultrasound examination of the eye is a safe and painless method that has no serious contraindications. However, in some cases, ultrasound examination of the eye may be undesirable or require special caution. Some of these cases:

  • Contact Gel Allergy:

Contact gel, which is applied to the eye or transducer to improve the conduction of ultrasound waves, may cause an allergic reaction in some patients, such as redness, itching, swelling, or irritation of the eye. In this case, you need to rinse your eye with water and consult a doctor for help. You may need to use a different type of gel or a different method to examine the eye.

  • Impaired corneal integrity:

If a patient has wounds, ulcers, erosions, or other damage to the cornea, ultrasound examination of the eye may aggravate them or cause infection. In this case, it is necessary to first treat the corneal damage and wait until it heals before performing an ultrasound examination of the eye. It may be necessary to use another method of examining the eye that does not require contact with the cornea, such as a B-scan with an immersion probe that is immersed in a special liquid rather than in the eye.

  • Presence of implants in the eye:

If the patient has artificial implants in the eye, such as artificial lenses, vitreoretinal prostheses, magnetic or metallic foreign bodies, then ultrasound examination of the eye may damage them or cause them to become dislodged. In this case, it is necessary to take into account the type and location of the implants and select the appropriate method and mode of ultrasound examination of the eye, which will not affect the implants or will affect them minimally.

You may need to use another eye test that doesn’t use ultrasound waves, such as optical coherence tomography (OCT).

Results of ultrasound examination of the eye

The results of an ultrasound examination of the eye are graphical or numerical data that is interpreted by an ophthalmologist. The results of an ultrasound examination of the eye may be normal or abnormal, depending on the presence or absence of changes in the structures of the eye. Some of the possible results of an ultrasound examination of the eye:

  • Normal result:

A normal ocular ultrasound result means that all structures of the eye are of normal shape, size, position, mobility, and echogenicity, and that there is no evidence of damage, inflammation, infection, tumor, detachment, or other pathology. A normal result of an ultrasound examination of the eye indicates good condition of the eye and its periorbital area, and does not require additional research or treatment.

  • Abnormal Finding:

An abnormal finding on an eye ultrasound means that one or more structures of the eye are abnormal, which may indicate the presence of damage, inflammation, infection, tumor, detachment, or other pathology. A pathological result of an ultrasound examination of the eye requires detailed analysis and comparison with other data, such as anamnesis, clinical symptoms, results of laboratory and instrumental studies, and may require additional research or treatment.

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