Ultrasound examination of the eye occupies an important place in ophthalmic practice - it is one of the main tools that complements the generally accepted methods for diagnosing eye pathologies. Ultrasound of the eye is a high-precision, painless and safe examination method that allows you to diagnose the state of the structures of the eyeball - the retina, eye muscles, lens. The technique of echo-ophthalmoscopy helps to establish an accurate diagnosis and detect various ophthalmic diseases in the early stages.
Ultrasound of the eye is used not only to detect and confirm various ophthalmic pathologies, but also to measure specific biometric parameters and determine a number of quantitative values. With the help of ultrasound, it is possible to carry out high-precision measurements of the eyeball, obtain information about the state of the structures and elements of the eye, the optic nerve, and evaluate blood flow in the vessels of the retina and orbit.
Methods of ultrasound diagnostics of the eyes
In ophthalmic practice, several methods of ultrasound diagnostics (scanning modes) are used, each of them has its own technical features, differs in diagnostic capabilities and is intended for specific medical cases.
One-dimensional echography (A-mode) is an effective way to determine the size of the eye, internal structures and elements. It is used before surgery.
An anesthetic is instilled into the eye for pain relief. The essence of the procedure is that the specialist drives the sensor along the eyeball. The information obtained is displayed on a computer monitor in the form of a graph, which indicates the key parameters of the eyeball.
Examination in A-mode allows to measure the axial length of the eye, the depth of its anterior chamber, and the parameters of the lens with high accuracy. These data are of decisive importance in preparing for cataract extraction, in accurately calculating the optical power of the artificial lens, and in diagnosing refractive errors. A-mode ultrasound can also identify and evaluate intraocular tumors.
Two-dimensional echography (B-mode) - a scan used to assess the internal structure of the organ of vision. A two-dimensional picture of the structures of the eye is displayed on the computer screen. B-mode scanning has more advanced features than A-mode. With its help, not a graph is obtained on the monitor, but a two-dimensional image with detailing of the internal structures of the eyeball: lens, retina, eye muscles, etc.
B-mode examination allows to evaluate and differentiate intraocular changes: determine the nature of the pathology, its shape, extent. Unlike the static A-mode, the B-scan displays the intraocular picture in dynamics, which greatly expands its diagnostic potential.
Along with A- and B-methods, other scanning modes are also used in ophthalmic diagnostics.
Combined method - a mode that combines the capabilities of A- and B-diagnostics. This technique combines the advantages of one- and two-dimensional echography.
Three-dimensional echography is a highly informative method that provides three-dimensional acoustic visualization of intraocular structures. Advanced 3D ultrasound technology provides a three-dimensional image of the organ of vision. This is an effective way that opens up wide possibilities. The image is given in volume and broadcast in real time, which allows you to assess the general condition of the eye in dynamics.
Color duplex scanning is a method that allows assessing blood flow parameters in the orbital vessels. The study of the blood flow of the vessels of the eye makes it possible to diagnose vascular pathologies, which are sometimes the cause of visual impairment.
All ultrasound techniques for examining the eye are absolutely safe. Ultrasonic waves do not adversely affect the structures of the eye.
How to perform an ultrasound examination of the eye
The procedure is performed in a sitting or lying position. It does not provide for any special training and its average duration is from 15 to 30 minutes.
Depending on the data that needs to be clarified by the ophthalmologist, there are two types of examination.
Diagnosis in A-mode is carried out by contact method. The patient is with open eyes. Superficial anesthesia is carried out. This is done with two goals: to achieve immobility of the eye and to ensure painless manipulation. The eyes remain open. A sterile probe is placed on the surface of the eyeball. The probe of the ultrasound machine is in contact with the eye and is slowly moved over the surface. Lacrimal fluid acts as a natural contact medium.
Diagnosis in B-mode is carried out with closed eyes. A hypoallergenic gel is applied to the eyelids, designed for ultrasound diagnostics. A sensor is placed on the upper eyelid. The specialist moves the sensor along the eyelid, periodically indicating what actions the patient needs to perform with his eyes.
The results of the study are recorded in the protocol. The procedure takes about half an hour. The information received is deciphered by a qualified doctor specializing in this area.
Indications for ultrasound examination of the eyes
- closed injuries and injuries of the eye;
- intraocular hemorrhages;
- suspicion of detachment of the inner membranes of the eye (retina, choroid);
- suspected damage/pathology of the optic nerve;
- progressive deterioration of vision;
- foreign bodies entering the eye (including those that are not detected radiographically);
- clouding of the optical media of the eye;
- suspicion of intraocular and intraocular neoplasms;
- diagnosed glaucoma, cataract, myopia (nearsightedness) and hypermetropia (farsightedness) at various stages;
- conducting preparatory measures before and after surgery;
- the need to evaluate the effectiveness of ongoing treatment;
- anomalies in the structure of the eye;
- assessment of the state of paraorbital tissue;
- hereditary ophthalmic pathologies;
- the patient has diabetes mellitus, nephropathy, hypertension.
Ultrasound diagnostics of the pathology of the eyeball and orbit can reveal the following conditions:
- destruction and displacement of intraocular tissues and membranes of the eye;
- decreased transparency of the refractive media of the eyeball;
- clouding of the vitreous body of various etiologies;
- lens dislocation;
- intraocular foreign bodies;
- vitreoretinal sutures;
- retinal detachments;
- changes in the adnexa of the eye (diseases of the lacrimal gland, lesions of the oculomotor muscles);
- intraocular tumors, neoplasms of the orbital cavity and optic nerve.
Ultrasound diagnostics is an indispensable tool for an ophthalmologist. Ultrasound of the eye is used to calculate the optical power of artificial lenses, to measure the biometric parameters of the eye and to identify various pathologies of the visual apparatus, eye vessels and optic nerve. Ultrasound scanning is of great value both in preparation for certain ophthalmic operations and in the dynamic evaluation of treatment results.
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