Ocular ultrasound

Ocular ultrasound (USG of the eye)

Ocular ultrasound is a non-invasive diagnostic method to assess the inside of the eyeball and orbital structures. The examination involves two eyes.

The examination uses high-frequency sound waves that propagate through the eyeball. The reflections (echoes) of the sound waves form an image of the structure of the eye. The examination usually takes approximately 10 minutes.

Ocular ultrasound makes it possible to assess the length and shape of the eyeball, e.g., in myopia, and to detect changes in the retina, such as retinal detachment (ablation). Thanks to its precision, the examination is used in the diagnosis of e.g., glaucoma, corneal diseases, or inflammatory diseases.

Indications for the examination

• Monitoring the progression of myopia
• Assessment of the vitreous body, choroid, and optic nerve
• Assessment of the retina, including (but not limited to) detachments, subretinal haemorrhages, and macular degeneration
• Diagnosis of ocular haemorrhages
• Diagnosis of tortuosity in the vitreous body
• Diagnosis of diabetic lesions
• Differentiation of intraocular tumours
• Assessment of eye and orbital structures in case of trauma and foreign bodies
• Evaluation of structures inside the eye in case of so-called opacities (e.g., corneal scarring or blepharitis, cataract, haemorrhage into the anterior chamber or chamber of the vitreous body, which prevent a direct view of the fundus)

How does the examination work?

The examination is usually carried out through closed eyelids after applying a special gel to the skin of the eyelids or the camera head. The gel facilitates movement of the probe over the skin and penetration of the ultrasound. For some measurements, it is necessary to apply the probe directly to the surface of the eyeball, after it has been anaesthetised beforehand. Please inform your doctor if you are allergic to any medication.

The examination is performed in a sitting or lying position. During the examination, the patient is asked to make specific movements of the eyeball so that the condition of the entire eyeball can be carefully examined and assessed. Any sudden movements of the head are not allowed during the examination, and the doctor's instructions must be followed.

Types of ocular ultrasound

An ultrasound of the eye is performed in two projections: A and B. During ocular ultrasound in projection A, biometric measurements are taken, such as the axial length of the eyeball, the radius of curvature of the cornea, or the depth of the anterior chamber. B-projection examination is performed to assess structures in the back of the eye and in the orbit. It is helpful in the diagnosis of cataracts, retinal detachment, tumours, or other eye diseases.

It is possible to drive after the examination, as it does not require pupil dilation.

Permanent medications, including ophthalmic medications, should not be discontinued before the examination.

How to prepare for the examination?

Make-up should be washed off and contact lenses removed before the examination. The patient presenting for the ultrasound should bring the results of previous examinations, if any, and an information sheet from the hospital, if they have one. If the examination is being performed for the first time, no documentation is needed.

Possible complications after the examination

Ultrasound examinations are safe for the patient and can be repeated many times. In the vast majority of cases, they do not cause any complications. The ultrasound examination of the eye is painless and non-invasive. During the examination, a small amount of gel that is placed on the eyelid may run down the skin. Occasionally, the patient may experience temporary blurred vision, redness of the eye, or a foreign body sensation under the eyelid (resulting from mechanical contact of the instrument with the eye).

Examination result

The result is available immediately after the examination.

After the examination, the patient receives a printout of the images of the eye structures examined, together with the results of their measurements.