Slit biomicroscopy. About eye biomicroscopy in detail. Slit Lamp Technique

Developer: Medelit Studio, KSMU 2006

Biomicroscopy- this is intravital microscopy of the eye tissues, a method that allows you to examine the anterior and posterior parts of the eyeball under different illumination and image size.

The study is carried out with using a special device- slit lamp, which is a combination of an illumination system and a binocular microscope (Fig. 1).

Rice. 1. Biomicroscopy using a slit lamp.

Thanks to the use of a slit lamp, it is possible to see the details of the tissue structure in the living eye.

The lighting system includes a slit-like aperture, the width of which can be adjusted, and filters of various colors. A beam of light passing through the slit forms a light section of the optical structures of the eyeball, which is examined through a slit lamp microscope. Moving the light gap, the doctor examines all the structures of the anterior part of the eye.

Patient's head mounted on a special slit lamp stand with chin and forehead support. In this case, the illuminator and microscope are moved to the level of the patient's eyes.

The light slit is alternately focused on that tissue eyeball which is subject to inspection. A beam of light directed onto translucent fabrics is narrowed and the light intensity is increased in order to obtain a thin light section.

In the optical section of the cornea, one can see foci of opacities, newly formed vessels, infiltrates, assess the depth of their occurrence, and identify various tiny deposits on its posterior surface. In the study of the marginal looped vascular network and the vessels of the conjunctiva, one can observe the blood flow in them, the movement of blood cells.

With biomicroscopy it is possible to clearly examine the various zones of the lens (anterior and posterior poles, cortical substance, nucleus), and in case of violation of its transparency, determine the localization of pathological changes.

Distinguish four ways of biomicroscopy depending on the nature of the lighting:

- in direct focused light when the light beam of the slit lamp is focused on the examined area of ​​the eyeball. In this case, it is possible to assess the degree of transparency of optical media and identify areas of turbidity;

- in reflected light. So you can consider the cornea in the rays reflected from the iris, when looking for foreign bodies or identifying areas of swelling;

- in indirect focused light, when the light beam is focused near the area under study, which allows you to better see the changes, thanks to the contract of strongly and weakly lit zones;

- with indirect diaphanoscopy, when reflective (mirror) zones are formed at the interface between optical media with different refractive indices of light, which makes it possible to examine tissue areas near the exit point of the reflected light beam (study of the angle of the anterior chamber).

With the specified types of lighting two methods can also be used:

- carry out research in a grazing beam(when the light strip is moved over the surface to the left and right with the handle of the slit lamp), which allows you to catch the unevenness of the relief (corneal defects, newly formed vessels, infiltrates) and determine the depth of these changes;

- perform research in a mirror field, which also helps to study the surface topography and at the same time reveal irregularities and roughness.

Use at biomicroscopy additionally aspherical lenses (such as Gruby lenses) make it possible to carry out ophthalmoscopy of the fundus (against the background of drug-induced mydriasis), revealing subtle changes in the vitreous body, retina and choroid.

The modern design and devices of slit lamps also make it possible to additionally determine the thickness of the cornea and its external parameters, evaluate its specularity and sphericity, and measure the depth of the anterior chamber of the eyeball.

Biomicroscopy is a method of examining the tissues and environments of the eye for the presence of any diseases, which is often used by ophthalmologists when examining their patients. This examination is based on the use of a special device - a slit lamp (an optical apparatus that combines a binocular microscope, a lighting system, as well as a number of additional elements that allow you to more accurately examine all eye structures).

With the help of such a lamp, not only biomicroscopy of the anterior sections of the eye is performed, but also its internal compartments - the fundus, the vitreous body. Biomicroscopy of the eye is a safe, painless and effective method of diagnosis.

It is used to examine not only the eye, but also other areas around it. This procedure is carried out in the following situations:

• Damage to the eyelids (injury, inflammation, swelling, and others);
• Mucosal pathologies (inflammation, allergic processes, various cysts and tumors of the conjunctiva);
• Disease of the cornea, protein membranes of the eye (keratitis, scleritis, episcleritis, degenerative processes in the cornea and sclera);
• Pathologies of the iris (, negative changes in the structure)
• At , ;
• Endocrine ophthalmopathies;
• Preoperative and postoperative diagnostics;
• Research in the process of treating eye diseases, in order to determine its effectiveness.

Contraindications

The procedure is not performed for the following patients:

• with mental disorders;
• under the influence of drugs or alcohol.

The main methodology for conducting

The examination takes place in a darkened room.

• The patient is positioned in front of the device, fixing his head on a special adjustable stand.
• The ophthalmologist sits on the other side of the apparatus, using a narrow beam of light directed at the eye, examines its front part with a microscope, determining whether there are any negative pathological abnormalities or changes in it.
• To conduct an examination in a child under three years old, he is immersed in a dream and placed in a horizontal position.
• The procedure takes about ten minutes.

• If it is necessary to do a biomicroscopy of the fundus, fifteen minutes before the procedure, the patient is instilled with a drug that dilates the pupils - a solution of tropicamide (for children under six years old - 0.5%, older - 1%).
• In case of injury and inflammation of the cornea, before diagnosing, the doctor instills a solution of fluorescein or Bengal rose to the patient, then rinses it off with eye drops. All this is done so that the damaged areas of the epithelium are stained, and the paint is washed off from healthy places.
• If a foreign body enters the eye, a solution of lidocaine is instilled before the procedure.

Varieties of the procedure

Taking the method of lateral focal illumination as a basis and further developing, biomicroscopy of the eye began to differ in the method of illumination:

Scattered (diffusion)

This type of illumination is the simplest, that is, the same side focal light, but stronger and more uniform.

This light makes it possible to examine the cornea, lens, iris at the same time, in order to determine the affected area, for further more detailed examination using other views.

Focal direct

The light is focused on the right specific place in the eyeball in order to reveal the places of turbidity, foci of inflammation, as well as to detect a foreign body. Using this method, you can determine the nature of diseases (keratitis, cataracts).

Focal indirect

To create contrast in illumination, to study any changes in the structure of the eye, a beam of light is focused near the area under consideration. Scattered rays falling on it create a dark field zone where the focus of the microscope is directed.

Using this method, unlike others, it is possible to examine the deep sections of the opaque sclera, contractions and ruptures of the sphincter of the pupil, distinguish true tumors of the iris from cystic formations, and detect atrophic areas in its tissues.

wavering

Combined light that combines direct and indirect focal lighting. Their quick change makes it possible to determine the light reaction of the pupil, to detect small particles of foreign bodies, especially metal and glass, which are not visible during radiography. Also, this type is used to diagnose damage in the membrane between the stroma and Descemet's eye membrane.

passing

It is used to diagnose the transparent media of the eye, which transmit light rays. Any part of the eye, depending on the area of ​​study, becomes a screen from which beams of light are reflected and the area under consideration becomes visible from behind in reflected light. If, for example, the diagnosed area is the iris, then the lens becomes the screen.

sliding

Lighting is directed from the side. Rays of light seem to glide over various surfaces of the eye. Especially often it is used to diagnose changes in the relief of the iris and to detect irregularities on the surface of the lens.

Mirror

The most complex type of illumination, which serves to study areas separating the optical media of the eye. A beam of light reflecting specularly from the anterior or posterior corneal surface makes it possible to examine the cornea.

fluorescent

Obtained by exposure to ultraviolet light. Before such a study, the patient drinks ten milliliters of a two percent solution of fluorescein.

Ultrasonic biomicroscopy

For a more detailed study of all structures and layers of the eye, which is not provided by simple biomicroscopy, ultrasound is used. It allows:

• obtain information about all layers of the eye down to microns, from the cornea to the equatorial zone of the lens;
• give full details of the anatomical features of the anterior chamber angle;
• to determine the interaction of the main components of the ocular system in the normal state and in pathological changes.

Biomicroscopy of the endothelium

It is carried out using a precision microscope connected to a computer. This device makes it possible to examine all layers of the cornea, and especially its inner layer, the endothelium, with microscopic maximum clarity. Thus, already in the early stages, it is possible to determine any pathological changes in the cornea. Therefore, the following groups of people need to regularly undergo such diagnostics:

• using contact lenses;
• after various eye surgeries;
• diabetics.

Procedure price

The cost of biomicroscopy in Moscow clinics ranges from 500 to 1200 rubles.

Biomicroscopy of the eye is a modern diagnostic method for examining vision, carried out using a special device - a slit lamp. A special lamp consists of a light source, the brightness of which can be changed, and a stereoscopic microscope. Using the method of biomicroscopy, an examination of the anterior segment of the eye is carried out.

Indications

This method is used by an ophthalmologist in combination with a standard visual acuity test and fundus diagnostics. Biomicroscopy is also used if a person suspects an eye pathology. Deviations in which the doctor prescribes this examination include: conjunctivitis, inflammation, foreign bodies in the eye, neoplasms, keratitis, uveitis, dystrophy, opacities, cataracts, and so on. Biomicroscopy of the eye is prescribed during the examination of vision before and after surgical treatment of the eye. Also, the procedure is prescribed as an additional measure for diseases of the endocrine system.

How is the procedure?

The process of biomicroscopy of the media of the eye does not cause pain in the patient. A person only observes a beam of light and fulfills the doctor's requests. The procedure does not require any special preparation and is carried out quickly. Biomicroscopy is carried out in a darkened room. The optometrist makes sure that the person takes the right position: the chin is on a special stand for the head, and the forehead is leaning against a certain place on the bar. After the patient has correctly placed his head on the stand, the optometrist begins the examination process. The doctor changes the direction and brightness of the light beam, while observing the reaction of eye tissues to changes in lighting. The process of biomicroscopy of the anterior segment of the eye allows you to find out about the state of the lens and the anterior zone of the vitreous body. The doctor also examines the tear film, the edges of the eyelids and eyelashes. The procedure lasts about 10 minutes. Usually this time is enough to make a diagnosis to the patient.

Ultrasound examination

The use of ultrasound as a diagnostic tool in modern ophthalmology is based on the properties of ultrasonic waves. Waves, penetrating into the soft tissues of the eye, change their shape depending on the internal structure of the eye. Based on data on the propagation of ultrasonic waves in the eye, the oculist can judge its structure. The eyeball consists of areas that have a different structure in acoustic terms. When an ultrasonic wave hits the boundary of two sections, the process of its refraction and reflection takes place. Based on the data on the reflection of waves, the ophthalmologist draws a conclusion about pathological changes in the structure of the eyeball.

Indications for ultrasound examination

Ultrasound is a high-tech diagnostic method that complements the classical methods for detecting pathologies of the eyeball. Sonography usually follows the classical methods of examination of the patient. In case of suspicion on the patient, radiography is first shown; and in the presence of a tumor - diaphanoscopy.

Ultrasound diagnosis of the eyeball is performed in the following cases:

• to study the angle of the anterior chamber of the eye, in particular its topography and structure;
• position research;
• for measurements of retrobulbar tissues, as well as examination of the optic nerve;
• during examination Studied (vascular and reticular) in situations with difficulties in the process of ophthalmoscopy;
• when determining the location of foreign bodies in the eyeball; assessment of the degree of their penetration and mobility; obtaining data on the magnetic properties of a foreign body.

Ultrasonic biomicroscopy of the eye

With the advent of high-precision digital equipment, it was possible to achieve high quality processing of echo signals obtained in the process of eye biomicroscopy. Improvements are achieved through the use of professional software. In a special program, the ophthalmologist has the ability to analyze the information received both during the examination and after it. The method of ultrasonic biomicroscopy owes its appearance to digital technologies, since it is based on the analysis of information from the piezoelectric element of a digital probe. For the survey, sensors with a frequency of 50 MHz are used.

Methods of ultrasound examination

In ultrasound examination, contact and immersion methods are used.

The contact method is simpler. In this method, the probe plate is in contact with the surface of the eye. The patient is given an anesthetic instillation into the eyeball, and then placed in a chair. With one hand, the ophthalmologist controls the probe, conducting a study, and with the other he adjusts the operation of the device. The role of the contact medium in this type of examination is the lacrimal fluid.

The immersion method of eye biomicroscopy involves placing a layer of a special liquid between the surface of the probe and the cornea. A special nozzle is installed on the patient's eye, in which the probe sensor moves. Anesthesia is not used in the immersion method.

The eyes are the most important sense organ. With its help, a person perceives 70% of information coming from outside. It's not just about image formation, but also about adapting to the terrain, reducing the risk of injury, and organizing social life.

Therefore, when the eyes are affected due to trauma, age-related changes or general diseases, the question is about disability and a noticeable decrease in the quality of life. It is for the purpose of early and accurate diagnosis of diseases of the organ of vision in ophthalmology that there is a fast and informative method of biomicroscopy.

What is the method of biomicroscopy

Biomicroscopy is a microscopic study of the structures of the visual organ in vivo (in a living organism) using a slit lamp (biomicroscope).

A slit lamp is an optical instrument consisting of:

• Binocular (for two eyes) microscope - an apparatus for obtaining an image magnified up to 60 times.
• Light source: 25W halogen or LED lamps.
• Slit diaphragm - for creating thin vertical or horizontal beams of light.
• Supports for the patient's face (support under the chin and forehead).
• Aspheric lens Gruda - for biomicroophthalmoscopy (examination of the fundus with a slit lamp).

The imaging method is based on the optical Tyndall effect. A thin beam of light is passed through an optically inhomogeneous medium (cornea - lens - vitreous body). The examination is carried out perpendicular to the direction of the rays. The resulting image is presented in the form of a thin cloudy light strip, the analysis of which is the conclusion of biomicroscopy.

Types of biomicroscopy

Examination of the eye with a slit lamp is a standard technique, however, for the study of individual structures of the eye, there are different methods of illumination of the biomicroscope, described below.

• diffuse lighting. Most often, this method is used as the initial stage of the study. With its help, with a small increase, a general examination of the structures of the eye is carried out.
• Direct focal illumination. The most used method, since it provides an opportunity to examine all the surface structures of the eye: the cornea, iris, lens. With the direct direction of the light beam, a wider area is first illuminated, then the diaphragm opening is narrowed - for a more detailed study. The method is useful for the early diagnosis of keratitis (inflammatory process in the cornea) and cataracts (clouding of the lens).
• Indirect focal illumination (dark field study). The attention of the doctor is drawn to areas located near the illuminated area. Under such conditions, empty vessels, folds of the Descemet's membrane and small precipitates (sedimentary complexes) are well visualized. In addition, the method is used for differential diagnosis of neoplasms of the iris.
• Variable (oscillatory) lighting is a method that combines the previous two methods. With a quick change of bright light and darkness, the reaction of the pupil is studied, as well as small foreign bodies, which in such conditions give a characteristic brilliance.
• Mirror field method: a study of reflective zones is carried out. Technically, this method is considered the most difficult, but its use makes it possible to detect the smallest changes in the surface of the structures of the eye.
• Transmitted (reflected) illumination. The study of the elements is carried out through a beam of light reflected from another structure (for example, the iris in the light reflected from the lens). The value of the method lies in the study of structures that are inaccessible under other lighting conditions. In reflected light, thin scars and swelling of the integument of the cornea, thinning of the pigment sheets of the iris, small cysts under the anterior and posterior lens capsules are visible.

Important! When examining the structures of the eye in reflected light, the areas under study acquire the color of the structures from which the light beam came. For example, when light is reflected from a blue iris, the lens under study acquires a gray-blue color.

In connection with the widespread use of ultrasound diagnostic methods, a new research option has appeared - ultrasound biomicroscopy. It can be used to detect pathological changes in the lateral parts of the lens, on the posterior surface of the iris and in the ciliary body.

Indications for the study

Given the capabilities of the method and a wide field of view, the list of indications for biomicroscopy is quite large:

• Conjunctivitis (inflammation of the conjunctiva).
• Corneal pathologies: erosion, keratitis (inflammation of the cornea).
• Foreign body.
• Cataract (clouding of the lens).
• Glaucoma (a condition characterized by an increase in intraocular pressure).
• Anomalies in the development of the iris.
• Neoplasms (cysts and tumors).
• Dystrophic changes in the lens and cornea.

Additional use of the Gruda lens allows diagnosing the pathology of the retina, optic nerve head and blood vessels located in the fundus.

Contraindications for biomicroscopy

There are no absolute contraindications for diagnostic manipulation. However, biomicroscopy is not performed on people with mental illness and patients under the influence of drugs or alcohol.

How is the study going

Biomicroscopy does not require preliminary preparation of the patient.

Doctor's advice! Biomicroscopy for children under 3 years of age is recommended to be performed in a horizontal position or in a state of deep sleep.

The patient is examined in a dark room (for greater contrast of illuminated and dark areas) in the ophthalmological office of a polyclinic or hospital.

Important! If an examination of the vitreous body and structures in the fundus is planned, mydriatics (drugs that dilate the pupils) are dripped immediately before the procedure.

Fluorescein drops are used to detect violations of the integrity of the cornea

The patient sits in front of the slit lamp, places his chin on a special stand, and presses his forehead against the crossbar. It is recommended not to move during the examination and to blink as little as possible.

The doctor, using the control joystick, determines the size of the gap in the diaphragm and directs the beam of light to the area under study. Using different methods of illumination, an examination of all structures of the eye is carried out. The duration of the procedure is 15 minutes.

Possible complications after biomicroscopy

Conducting biomicroscopy does not cause discomfort or pain. The only undesirable consequence may be an allergic reaction to the drugs used.

Important! If a third-party body is found during the study, Lidocaine eye drops are used before removing it. Therefore, you need to notify the doctor about the presence of an allergy to the drug.

Advantages of the method

The ability to study the state of the superficial and deep structures of the visual organ makes biomicroscopy the method of choice for diagnosing most ophthalmic diseases. For an objective assessment of the benefits of this study, a comparison with other diagnostic methods is necessary.

Examination of the eye with a slit lamp and a change of illumination allows you to see the smallest signs of pathologies of all structures. A separate advantage of the method is its cheapness when using new biomicroscopes with aspherical lenses and tonometers, replacing traditional tonometry and ophthalmoscopy.

How to decipher the results of biomicroscopy

When examining a healthy eye, the following are determined:

• Cornea: convex-concave prism with a slight bluish glow. Nerves and vessels are visible in the thickness of the cornea.
• Iris: the pigment layer is represented by a colored (depending on eye color) fringe around the pupil, and in the ciliary zone, zones of ciliary muscle contraction are visible.
• Lens: A transparent body that changes shape when focused. It consists of an embryonic nucleus covered with a cortical layer, an anterior and a posterior capsule.

Variants of possible pathologies and the corresponding biomicroscopic picture are presented in the table.

Due to its diagnostic value, ease of use and safety, biomicroscopy has become a standard procedure for examining ophthalmic patients along with visual acuity measurement and fundus examination.

The video below describes the biomicroscopy technique.

Examination of the internal structures of the eye is necessary when there is a suspicion of any diseases or anomalies of the anterior or posterior part of the eyeball. The use of a special microscope for this purpose, combined with a powerful lighting device, is called biomicroscopy. This study helps to identify and study in detail many deviations within the visual organ.

Biomicroscopy: basic concepts

Biomicroscopy is a study of the internal state of the eyeball using a medical device called a slit lamp. Includes a wide range of sophisticated pathology imaging techniques of varying origin, texture, color, transparency, size and depth.

The slit lamp allows for a detailed microscopic examination of the eye.

The slit lamp is an instrument consisting of a high-intensity light source that can be focused to direct a thin strip of light into the eye through various filters that provide the location and size of the slit. It is used in combination with a biomicroscope, which, together with the illuminator, is mounted on the same coordinate table. The lamp facilitates inspection of the anterior and posterior segments of the human eye, which include:

• eyelid;
• sclera;
• conjunctiva;
• iris;
• natural lens (crystalline lens);
• cornea;
• vitreous body;
• retina and optic nerve.

The slit lamp is equipped with a diaphragm that forms a slit up to 14 mm in width and height. The binocular microscope includes two eyepieces and an objective (magnifying lens), the optical power of which can be adjusted using a dial that changes the magnification. The range of gradual increase is from 10 to 25 times. With an additional eyepiece - up to 50-70 times.

Binocular slit-lamp examination provides a stereoscopic magnified view of eye structures in detail, allowing for anatomical diagnoses in a variety of eye conditions. The second, manual lens is used to examine the retina.

For a full-fledged examination with a biomicroscope, there are various methods for illuminating slit lamps. There are six types of basic lighting options:

1. Diffuse illumination - examination through a wide aperture using glass or a diffuser as a filter. It is used for general examination in order to detect the localization of pathological changes.
2. Direct focal illumination is the most commonly used method, which consists in observing with an optical slit or direct focal beam hit. A slit of thin or medium width is directed and focused on the cornea. This type of illumination is effective in determining the spatial depth of eye structures.
3. Specular reflection, or reflected illumination, is a phenomenon similar to the image visible on the sunny surface of a lake. Used to assess the endothelial contour of the cornea (its inner surface). To achieve a mirror effect, the tester directs a narrow beam of light towards the eye from the side of the temple at an angle of about 25-30 degrees to the cornea. A bright specular reflection zone will be visible on the corneal epithelium (outer surface).
4. Transillumination (transillumination), or examination in reflected (transmitted) light. In some cases, illumination with an optical slit does not provide sufficient information or is simply impossible. Transillumination is used to examine transparent or translucent structures - the lens, the cornea - in the reflection of rays from deeper tissues. To do this, highlight the background of the object under study.
5. Indirect lighting - a light beam, passing through translucent fabrics, is scattered, simultaneously highlighting certain places. Used to detect pathologies of the iris.
6. Scleral scattering - with this type of illumination, a wide light beam is directed to the limbal region of the cornea (the edge of the cornea, the place of articulation with the sclera) at an angle of 90 degrees to it to create the effect of light scattering. In this case, a certain halo appears under the cornea, which illuminates its anomalies from the inside.

The slit lamp makes it possible to study the structural parts of the cornea:

• epithelium;
• endothelium;
• back border plate;
• stroma.

And also - to determine the thickness of the transparent outer shell, its blood supply, the presence of inflammation and edema, and other changes caused by trauma or dystrophy. The study allows you to study in detail the condition of the scars, if they exist: their size, adhesions with surrounding tissues. Biomicroscopy reveals the smallest solid deposits on the reverse surface of the cornea.

If a pathology of the cornea is suspected, the doctor additionally prescribes confocal microscopy - a method for assessing the morphological changes in this organ using a special microscope with a magnification of 500 times. It allows you to explore in detail the layered structure of the corneal epithelium.

With biomicroscopy of the lens, the doctor examines the optical section for possible clouding of its substance. Determines the location of the pathological process, which often begins precisely on the periphery, the state of the nucleus and capsule. When examining the lens, almost any kind of illumination can be used. But the first two are the most common: diffuse and direct focal illumination. In this order, they are usually carried out. The first type of lighting allows you to evaluate the general appearance of the capsule, to see the foci of pathology, if any. But for a clearer understanding of exactly where the "breakdown" occurred, it is necessary to resort to direct focal lighting.

Examining the vitreous body with a slit lamp is not an easy task that not every novice in ophthalmology can handle. The vitreous body has a jelly-like consistency and lies quite deeply. Therefore, it weakly reflects light rays.

Biomicroscopy of the vitreous body requires an acquired skill

In addition, the narrow pupil interferes with the study. An important condition for high-quality biomicroscopy of the vitreous body is a preliminary drug-induced mydriasis (pupil dilation). The room where the inspection is carried out should be as dark as possible, and the area under study, on the contrary, should be quite brightly lit. This will provide the necessary contrast, since the vitreous body is a weakly refractive, slightly reflective optical medium. The doctor uses mostly direct focal illumination. When examining the posterior parts of the vitreous body, it is possible to study in reflected light, where the fundus plays the role of a reflective screen.

Concentration of light on the fundus allows you to examine the retina and optic nerve head in the optical section. Early detection of neuritis or swelling of the nerve (congestive papilla), retinal breaks helps in the diagnosis of glaucoma, prevents optic nerve atrophy and decreased vision.

The slit lamp will also help determine the depth of the anterior chamber of the eye, detect cloudy changes in moisture and possible impurities of pus or blood.
A wide choice of types of lighting thanks to special filters allows you to study the vessels well, detect areas of atrophy and tissue ruptures. Less informative is biomicroscopy of translucent and opaque tissues of the eyeball (for example, conjunctiva, iris).

Slit lamp device: video

Indications and contraindications

Biomicroscopy is used to diagnose:

• glaucoma;
• cataracts;
• macular degeneration;
• retinal detachment;
• corneal damage;
• blockage of retinal vessels;
• inflammatory diseases;
• neoplasms, etc.

And you can also detect a wound in the eye, foreign bodies in it, which are not able to show the x-ray.

There are no absolute contraindications for slit lamp examination. Nevertheless, it is worth paying attention to some important nuances associated with eye injuries:

Fundus observation is known as fundus lens ophthalmoscopy. But with a slit lamp, direct observation of the bottom is impossible due to the refractive power of the eye media, as a result of which the microscope does not provide focusing. Rescues the use of auxiliary optics. Using a diagnostic three-mirror Goldman lens in the light of a slit lamp, it is possible to examine those peripheral areas of the retina that cannot be examined with ophthalmoscopy.

Advantages and disadvantages of the method

Biomicroscopy has a number of significant advantages over other methods of ophthalmic examination:

• Possibility of exact localization of anomalies. Due to the fact that the beam of light from a slit lamp during biomicroscopy can penetrate into the structures of the eye at different angles, it is quite realistic to determine the depth of pathological changes.
• Enhanced diagnostic capabilities. The device provides illumination in vertical and horizontal planes at different angles.
• Convenience in a detailed survey of a particular area. A narrow beam of light directed into the eye provides a contrast between the illuminated and dark areas, forming the so-called optical section.
• Possibility of biomicroophthalmoscopy. The latter is successfully used for examination of the fundus.

The method is considered highly informative, devoid of significant shortcomings and contraindications. But in some cases it is advisable to prefer a hand-held device to a stationary one, although a hand-held slit lamp has limited capabilities. For example, it is used:

• for biomicroscopy of the eyes of babies who are still in a supine position;
• when examining restless children who cannot sit out the allotted time at an ordinary slit lamp;
• for examining patients in the postoperative period, during strict bed rest, it is an alternative to the stationary version of the device.

In these cases, a hand lamp has advantages over diffuse (diffuse) lighting, it makes it possible to examine in detail the surgical incision and the anterior chamber with intraocular fluid, the pupil, and the iris.

The manual slit lamp has modest capabilities, but sometimes it is indispensable

Carrying out the procedure

The examination is carried out in a darkened room. The patient sits in a chair, puts his chin and forehead on a support to fix his head. She must be motionless. It is desirable to blink as little as possible. Using a slit lamp, the ophthalmologist examines the patient's eyes. To aid examination, a thin strip of fluorescein (luminous dye) paper is sometimes applied to the edge of the eye. This stains the tear film on the surface of the eye. The paint is later washed away with tears.

Then, at the discretion of the doctor, drops may be needed to dilate the pupils. It is necessary to wait 15 to 20 minutes for the medicine to take effect, after which the examination is repeated, which allows you to check the back of the eye.

Sometimes it is necessary to dilate the pupil medically before biomicroscopy.

First, the ophthalmologist again tests the anterior structures of the eye, and then, using a different lens, examines the back of the organ of vision.

As a rule, such a test does not cause significant side effects. Sometimes the patient experiences some light sensitivity for several hours after the procedure, and dilating drops can increase eye pressure, leading to nausea with headache. Those who experience serious discomfort are advised to consult a doctor immediately.

Adults do not need special preparation for the test. However, children may need it in the form of atropinization (dilation of the pupil), depending on age, previous experience and level of confidence in the doctor. The whole procedure takes about 5 minutes.

Research result

During the examination, the ophthalmologist visually assesses the quality and condition of the structures of the eye in order to detect possible problems. Some models of slit lamps have a photo and video module that record the examination process. If the doctor finds that the results are not normal, this may indicate such diagnoses:

• inflammation;
• infection;
• increased pressure in the eye;
• pathological change in the ophthalmic arteries or veins.

For example, in macular degeneration, a doctor will find drusen (optic disc calcifications), which are yellow deposits that can form in the macula - an area on the retina - early in the disease. If the doctor suspects a certain vision problem, he will recommend further detailed examination to make a final diagnosis.

Biomicroscopy is a modern and highly informative examination method in ophthalmology, which allows you to examine in detail the eye structures of the anterior and posterior sections under different illumination and image magnification. Special preparation for this study, as a rule, is not necessary. Thus, a five-minute procedure makes it possible to effectively control the health of the eye and prevent possible deviations in time.