What is staphiloma and why does it arise. False and true myopic retinal staphyloma Important clinical signs

24.05.2020

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Definition

Myopic degeneration is a degenerative condition of the retina, in which there is a thinning of the pigment epithelium and choroid, atrophy of the retinal pigment epithelium, CNV and subretinal hemorrhages in patients with progressive lengthening of the eyeball with myopia of more than 6 diopters.

The prevalence of myoic degeneration varies among different races and ethnic groups and is more common in women than in men.

Anamnesis

Patients with complicated myopia slowly lose central vision due to progressive retinal atrophy in the macular region. A more dramatic loss of vision can occur due to macular subretinal hemorrhage or CNV. If subretinal hemorrhage, unrelated to CNV, is resorbed, spontaneous improvement in vision occurs.

Important clinical signs

It is believed that the clinical manifestations of myopic degeneration are associated with progressive lengthening of the eyeball. A distinctive feature is the so-called myopic cone (atrophy) of the retinal pigment epithelium around the optic nerve head in the form of a crescent or ring (Fig. 2-14, A). This atrophic area is usually located on the temporal side of the disc, but it can be located anywhere around the disc and spread to the macular region.

The optic disc itself can be obliquely entering or elongated in the vertical direction, both of these signs can be present (Fig. 2-14, B). Changes in the macular area can cause vision loss.

These changes include tortuous areas of atrophy in the posterior pole of the eyeball, which can invade the fossa region. Lacquer cracks are spontaneous linear ruptures of the Bruch's membrane (see Fig. 2-14, B) and develop in 4% of patients with a high degree of myopia; lacquer cracks are considered the cause of spontaneous subretinal hemorrhages. not related to CNV (Fig. 2-14, C).

Fuchs spots are rounded areas of subretinal hyperpigmentation, occasionally with surrounding areas of atrophy, which are considered the outcome of subretinal hemorrhage or CNV. Fuchs "spots are detected in 10% of cases with high myopia in patients over 30 years old.

Figure: 2-14, A. Mystical degeneration, myopic cone. Myopic cone from the temporal side. The "thinning" of the retinal pigment epithelium is determined (the true borders of the optic nerve head are visible on the enlarged image).
B. Myopic degeneration, obliquely incoming optic disc. Pronounced oblique entry of the optic nerve head with a temporal cone and a varnish fissure above the central fossa (arrow).
B. Myopic degeneration, retinal hemorrhage. Spontaneous subretinal (foveal) hemorrhage from the lacquer fissure without choroidal neovascularization.
D. Myopic degeneration, choroidal neovascularization. Subretinal choroidal neovascularization (arrow) with pigmentation and a small amount of subretinal fluid.

Associated clinical signs

Choroidal neovascularization develops in patients with myopia with a frequency of 5 to 10% of cases when the length of the anteroposterior axis of the eye is more than 26.5 mm (Fig. 2-14, D), often in combination with varnish cracks. In the fundus, one can observe the posterior staphyloma - excavation in the posterior pole, accompanied by chorioretinal atrophy (Fig. 2-14, E).

Figure: 2-14, D. Myopic degeneration, posterior staphyloma. Shown staphyloma around the optic nerve head.
E. Myopic degeneration. Extensive chorioretinal atrophy in the posterior pole and periphery of the retina of the right eye.
G. Myopic degeneration, Extensive chorioretinal atrophy in the posterior pole and periphery of the retina of the left eye.

At the periphery of the retina, diffuse redistribution of pigment and spotty or diffuse areas of chorioretinal degeneration are determined (Fig. 2-14, F, G). Posterior vitreous detachment is more common in patients with degenerative myopia and develops at a younger age. Lattice degeneration occurs in myopic degeneration no more often than on average, but such patients are at increased risk of retinal rupture and detachment.

Differential diagnosis

... Syndrome of the oblique entrance of the optic nerve head.
... Coloboma of the optic nerve head.
... Syndrome of presumptive ocular histoplasmosis.
... Age-related macular degeneration.
... Girat atrophy.

Diagnostics

Anamnesis, refraction measurements, eye length measurements, and many ophthalmoscopic features all help in the diagnosis of myopic degeneration.

Fluorescence angiography is indicated to assess CNV.

Prognosis and treatment

There is no effective therapy to prevent the progression of myopia and the degenerative effects of this pathology on the retina. According to some data, sclero-strengthening operations and scleral resection methods limit the lengthening of the eyeball, but do not provide complete stabilization of the process or reliable improvement of vision.

Patients with myopic CNV should be cautious enough to recommend laser coagulation. Without treatment, CNV often remains small in size, and expansion of the area of \u200b\u200batrophic sites after photocoagulation can lead to further progression of vision loss. In subfoveal CNV, it may be appropriate to use photodynamic therapy with verteporfin. Without treatment, CNV in myopic degeneration can remain stable without a significant decrease in visual acuity, in contrast to age-related macular degeneration.

S.E. Avetisov, V.K. Sealing wax

In patients with myopia, in most cases there are changes in the fundus (around the optic nerve head).

There are several types of such pathologies:

Myopic cone;
Circumferential light reflexes presented in the form of an arc;
True staphylomas.

Even in patients with an initial form of myopia near the optic nerve head, parallel reflexes are detected, which are located at the border of the disc. They can be single, double. In the case of detection, we are often talking about the initial anomalies of the structure of the wall of the eye in the region of the posterior pole.

Myopic cone

Myopic cones look like crescent-shaped formations of white color with clear boundaries. They are located in the temporal region of the disc. On the border of such pathological formations, there is often pigmentation, the severity of which can be different (up to complete overlap with dark pigment). Sometimes pigment formations in the form of lumps are located around the cone. In some cases, in the cone itself, it is possible to identify the embryos of choroidal vessels.

In the case of a small diameter, less than 20% of the diameter of the optic nerve head, the cone is called a sickle. If the diameter of the formation exceeds these values, then it is called the actual cone. Sometimes such circular cones are also called staphylomas, but their structure differs from the structure of true staphylomas.

Sickles are formed as a result of the fact that the optic nerve canal is not perpendicular to the plane of the scleral membrane. In this case, the wall of such a channel looks like a sickle. The color of this neoplasm is associated with the translucence of the white sclera. The formation of cones is associated with atrophic processes in the pigment epithelial layer near the disc and with stretching of the sclera itself. This leads to an improvement in the transillumination of the choroid, which also undergoes degenerative processes. The sclera shines through this shell. The formation of cones most often does not affect visual acuity.

In patients with high myopia, a ring-shaped cone covers the area around the optic nerve head.

Staphiloma

Staphylomas are understood as true protrusion of the sclera. Most often, they form in patients with a high degree of myopia. During ophthalmoscopy, the doctor visualizes a protruding circle located in the immediate vicinity of the optic nerve. here the characteristic inflection of the retinal vessels is sometimes revealed.

In the case of a progressive course of myopia, the doctor discovers terassoidal changes in the fundus associated with the gradual formation of staphilomas.

At the end of the last century, scientists considered such changes to be developmental anomalies associated with a violation of the formation of the choroid at the edge of the optic nerve head. If there is a discrepancy between the size of the disc and the sclerosoroidal canal, a circular cone may form. In addition to ophthalmoscopy data, in this case, it is necessary to take into account the clinical and statistical parameters:

Cones can form not only against the background of myopia, but also in the case of hyperopia or normal refraction.
The results of the pathological examination are similar in patients with normal refraction and with myopia.
Even with a single eye axis, the size of the cone can vary considerably.

The following facts testify in favor of the acquired character of the cones:

A significant deviation in the shape of the eye contributes to the formation of cones.
With congenital cones in infants, the histological picture differs from the data obtained in the study of cones in patients with an increase in the axis of the eye.
Even with the same axis of the eye, the shape of the apple can be either spherical or elongated. Older authors believe that small cones are more often congenital, while large cones are associated with a pathological process.
In children under seven years of age and in newborn patients, braids are much less common than in older patients.
In older students, there is an increase in the number of cones.
In adult patients, it is usually possible to establish a connection between the appearance of cones and the presence of myopia.
Analysis of data on the length of the eye axis in patients with or without cones.

With true staphyloma against the background of myopia, the posterior hemisphere of the eye protrudes. They are also called true posterior sclerectasias. A characteristic feature of these neoplasms is the presence of folds in the area of \u200b\u200bthe fundus (temporal region). The retinal vessels in this zone form an inflection, which is similar to the inflection on the background of glaucomatous excavation.

Is a pathological protrusion of the posterior surface of the sclera. Clinically manifested by a decrease in visual acuity and a narrowing of the visual field. In the fundus, diffuse atrophy of the retinal pigment epithelium is revealed, the presence of peripheral vitreochorioretinal dystrophy or retinal traction is possible. For diagnostics, an external examination is used, visual acuity and the nature of vision are examined, tonometry, biomicroscopy are performed. Additional methods include ultrasound of the eyeball, computer perimetry, and electroretinography. Treatment of staphyloma is conservative (drugs and physiotherapy to improve blood supply to the retina, strengthen the sclera and relax the accommodation of the eye) and surgical (aimed at strengthening the posterior surface of the sclera).

General information

Staphyloma (staphyloma; Greek staphylē - bunch of grapes + -ōma) is a pronounced deformation of the sclera with pathological prolapse and lengthening of the eye axis. Scleral staphiloma occurs with high degree of myopia. Myopia is the most common disease and the leading cause of blindness in developed countries. In Russia, 15% of the population suffers from refractive errors, 3% of them have a complicated form with pronounced changes in the fundus. Myopic staphyloma develops between the ages of 20 and 40. It is often accompanied by other pathological changes in the structure of the eye and is the cause of disability at a young working age. Rehabilitation of patients with high myopia and prevention of complications still remain important problems in modern ophthalmology.

Causes and symptoms of staphyloma

The scleral membrane is the outer opaque capsule of the eyeball and contains in its structure cellular elements that are immersed in the main substance, consisting of glycosaminoglycans, protein, polysaccharide complexes. 70% of the sclera consists of collagen protein, its bundles - fibrils form a special plexus with elastic fibers. Due to this structure, the scleral membrane performs its main functions - maintaining the strength and elasticity of the eyeball. With the development of high myopia, loosening of the collagen fibers of the sclera occurs. In the posterior pole, the number of proteases increases, which destroy the adhesive bonds in elastic fibers and lead to the formation of staphyloma.

Clinically, staphiloma is manifested when complications develop in a patient with high myopia. Most often, there is a significant decrease in visual acuity, rapid fatigue, a feeling of heaviness in the eyes. Possible narrowing of the field of vision in one eye. On examination, an ophthalmologist can detect an extensive staphyloma in the fundus (a white focus of atrophy in the form of a ring at the posterior pole), diffuse atrophy of the pigment epithelium, "albinotic" color of the fundus, the presence of peripheral vitreochorioretinal dystrophy or traction. The defeat is often bilateral. From the complications of myopic staphyloma, the occurrence of retinal dystrophy, the formation of hemorrhagic detachment of the retina, destruction of the vitreous body, the development of cataracts, and open-angle glaucoma are distinguished.

Diagnostics and treatment of staphyloma

The diagnosis of staphyloma begins with the collection of anamnestic information. Then the ophthalmologist performs an external examination, examines visual acuity and the nature of vision, conducts tonometry. Slit lamp biomicroscopy is the main method for diagnosing staphyloma. Be sure to perform a study of refraction of the eye using cycloplegia. Additional methods include ultrasound of the eye with measurement of the anteroposterior axis and computer perimetry (to identify paracentral defects of the visual field). To diagnose the state of the macular region, optical coherence tomography is used. Electroretinography helps to identify functional disorders in the retina and choroid of the eyeball.

Treatment of myopic staphyloma is complex, including both surgical and conservative techniques. The primary goal of therapeutic measures is to reduce the progression of myopia. Conservative therapy of staphyloma includes the use of drugs that affect the relaxation of accommodation, help to strengthen the scleral membrane, improve the hemodynamics of the eye, metabolic processes in the retina and choroid, and increase visual function.

With the development of hemorrhages in the retina, it is necessary to use hemostatic, absorbable and desensitizing agents. Physiotherapy treatment is also indicated. Prescribe electrophoresis, laser stimulation or magnetophoresis. Rigid orthokeratology lenses can be used to reduce the rate of myopia progression. Surgical treatment of staphyloma is aimed at preventing further stretching of the scleral membrane. Various techniques are used to strengthen the posterior pole of the eyeball.

Prognosis and prevention of staphyloma

The prognosis is often dubious. Prevention of myopic staphyloma is aimed at reducing the progression of myopia. It includes measures to promote health and physical development in childhood and adolescence, to teach children and adults the rules of vision hygiene. It is necessary to organize high-quality lighting in schools and workplaces, monitor compliance with sleep and rest, limit the use of tablets and phones by children, and regularly visit an ophthalmologist for preventive examinations.

23-02-2014, 22:44

Description

Clinical classification of myopia

When examining a patient with myopia, the doctor must, first of all, evaluate it by a number of clinical signs that can help to correctly predict the course of the disease and develop an adequate treatment strategy. For the convenience of practical ophthalmologists, Professor E.S. Avetisov suggested using the clinical classification of myopia. It includes an assessment of the condition of the eyes according to a number of parameters:

By the degree of myopia:

weak 0,5-3,0 diopters;
average 3,25-6,0 diopters;
high 6,25 diopters and above.

For equality of refraction of two eyes:

isometropic;
anisometropic.

By the presence of astigmatism:

no astigmatism;
with astigmatism.

By the time of occurrence:

congenital;
acquired early (in preschool age);
acquired at school age;
late acquired (in adulthood).

With the flow:

stationary;
slowly progressive (less 1,0 diopters per year);
rapidly progressing ( 1,0 diopters and more per year).

By the presence of complications:

uncomplicated;
complicated.

Complicated myopia is divided according to the form and stage of the process.

By form:

chorioretinal (peridiscal, macular dry and wet, peripheral, widespread)
vitreous;
hemorrhagic;
mixed.

By the stage of morphological changes:

initial (myopic sickle up to 1/3 disc diameter (DD);
developed (cone up to 1 DD, macular pigmentation, fundus depigmentation);
far gone (myopic staphyloma around the optic nerve head or cone more than 1 DD, disc blanching, severe depigmentation of the fundus, mottling of the macula, atrophic foci in other areas of the fundus).

By the stage of functional changes - visual acuity:

0,8-0,5; -0,4-0,2; -0,1-0,05;
0,04 and below.

The indication for the treatment of uncomplicated myopia, as a rule, is its progressive nature. Therefore, in this chapter, we will focus mainly on the symptoms that accompany myopic ones all their lives, and that appear in them during the period of increased refraction of the eyes.

The study of the anamnesis of the disease of patients with myopia indicates a sharp "rejuvenation" of this process, which occurred in the last 5-10 years. If earlier myopia in most children (90%) debuted at the age of 10 years and older, now more and more often we see children in whom she first appeared in 5-7 -years old. In these cases, myopia, left without treatment, develops very rapidly, increasing by 1,5-2,0 diopters per year.

It is obvious that such patients are at risk of complicated myopia with an invapidizing course. Therefore, they should receive an adequate therapeutic complex at least twice a year.

The study of the clinical symptoms characteristic of progressive myopia should begin, as usual, with the collection of patient complaints. Most often, the child notices that his vision from the board has become worse. Teachers note that he makes mistakes when copying information from the blackboard into a notebook or copy it from a neighbor's notebook. Parents pay attention to the fact that the child bends low over the table while doing homework, squints when looking into the distance. Sometimes they are brought to the ophthalmologist by the fact that he has unusually wide pupils. If the student is already using glasses, the progressive nature of myopia will be indicated by deterioration of vision in glasses, which become "small".

Sometimes patients complain of a short-term darkening in the eyes, a rapidly emerging feeling of fatigue, pain in the eyes during classes and heaviness in the eyelids by the end of the working day, double vision of letters and words, blurring of the written text.

Less commonly, they are disturbed by photopsies in the form of lightning, light objects, flares, twinkling stars, pulsating spots, and so on. As a rule, these complaints occur in patients with cervical osteochondrosis, CS dysfunction and cerebral vascular symptoms. Complaints about impaired focusing of vision and rapidly approaching fatigue in the eyes while working at close range are due to a violation of the accommodative function of the eyes.

Collecting anamnesis, it is necessary to pay attention to other manifestations of cerebral vascular changes and pathology of the CS. Most children note the coincidence of the timing of the onset of headaches with visual impairment or an increase and increase in cephalalgia during the progression of myopia.

Some children have dizziness, vestibular disorders, less often - complaints indicating more severe cerebral ischemia - attacks of fainting with short-term loss of consciousness, temporary weakness in the extremities (the hand is weak and the briefcase falls out, the leg begins to twist and walk badly), the phenomenon of hypesthesia bodies, choking on food and others. It is clear that the deterioration of vision and the progression of myopia against this background are due to a decrease in the accommodative function of the eyes during an increase in cerebral hemodynamic impairment.

Many children note the connection of headaches with head turns, pain in the neck after sleeping in an uncomfortable position, and prolonged exercises with the head tilted. Sometimes there is a feeling of anesthesia of the skin in the neck, "running" goose bumps, crunching and crackling when turning the head.

For the clinical differential diagnosis of "vascular" and "hypertensive" (associated with increased ICP) headaches, it is important to clarify the nature of cephalgia, accompanying symptoms, time of onset and therapeutic measures that bring relief. "Vascular" headaches are more often localized in the temples, forehead and back of the head, are pulsating or constricting in nature.

Characterized by their appearance in the morning after sleeping in an uncomfortable posture for the neck, working at close range with head anteflexion, after school hours in the afternoon (neuropathologists call them "school" headaches). At the height of the headache, nausea may appear, and even vomiting, which does not bring relief. Such pains disappear after rest, massage or applying a heating pad to the neck area, taking vasodilators.

Hypertensive cephalalgia often occurs at night, when venous congestion worsens CSF flow and increases ICP. They are bursting in nature, accompanied by vomiting, which gives a diuretic effect and leads to relief of the general condition. In addition to analgesics, diuretics control hypertensive headaches.

Nearsighted people are characterized by "vascular" headaches with a neurological symptom complex, indicating their connection with pathology in the SHOP.

Ophthalmic examination

Refraction and visual acuity

The determination of the degree of myopia, contrary to the established tradition, must be carried out without cycloplegia. Our studies have confirmed numerous works of recent years, the authors of which are convinced that in most cases the results of autorefractometry and skiascopy in conditions of cycloplegia in myopia coincide with the data of subjective examination of patients.

Among our patients, this coincidence was recorded in 57% cases. Have 25% children after atropinization myopia decreased by 0,5 diopters, and at 18% - increased as much. OG Levchenko explains a similar phenomenon by a violation of the interaction of the two divisions of the autonomic innervation of the ciliary muscle as a result of weakening of accommodation.

At present, the use of cycloplegia in patients with myopia is advisable only if it is necessary to determine the degree of myopia to resolve the issue of the state of vision for service in the Armed Forces, naval, aviation and other schools. Now it is already clear that the refraction of the eye under conditions of atropinization actually does not always correspond to reality, as it was believed earlier. The fact is that this artificially paralyzes the part of the ciliary muscle responsible for its contractile function.

Naturally, in this case, the action of the antagonistic part, which provides accommodation for the distance and is innervated by the sympathetic nerve, begins to prevail. The true value of refraction can be obtained only under conditions of rest of accommodation, when the tone of the accommodative muscle is balanced.

That part of the tone, which is eliminated by atropine, is now called the habitual or physiological tone of the ciliary muscle. Many old ophthalmologists still mistakenly call it "accommodation spasm" and unsuccessfully try to rid patients of it by regular instillation of atropine. This not only does not help to cure myopia, but often leads to accommodation paralysis. In myopic, there is already paresis of the ciliary muscle, manifested by the weakness of the contractile function of accommodation, and atropine further weakens it.

As for the true spasm of accommodation, it is extremely rare with myopia. According to our data - in 0,2% cases. Spasm of accommodation is more typical for weak refraction - hyperopia in children with astigmatism, especially mixed. In these cases, it compensates for the refractive error. Therefore, for the correct prescription of glasses, these patients need the use of cycloplegics. The magnitude of the physiological tone of a healthy emmetropic eye is. according to different authors, from 1.0 before 1,42 diopters, in myopic it is reduced to 0,33-0,5 diopters, so it is logical to consider the difference between refraction before and after cycloplegia as a spasm of accommodation more than 1,5 diopters.

It is well known that visual acuity in myopia does not always correspond to its degree. However, most often with myopia - 0,5 dioptric patients see 0,8, -1,0 diopters - 0,6 , at - 1,5 diopters - 0,3. Myopia - 2,0 diopters and above more often allows you to see 0,1. However, there are times when patients with moderate and even high myopia may consider 0,2-0,3 ... and vice versa, the same amount is seen with myopia -1,0 diopters.

As you know, when correcting myopic refraction, its value is determined by the minimum negative glass, which gives the maximum visual acuity. Most often, this visual acuity corresponds 1,0 , less often - 1,5. Have 19% patients with progressive myopia, it can decrease to 0,6-0,9 .

In some cases, this is due to uneven contraction of the fibers of the paretic ciliary muscle and functional astigmatism, sometimes - organic congenital astigmatism, and in some cases - dysfunction of the visual analyzer. As a rule, treatment aimed at restoring accommodation and cerebral circulation can improve visual acuity in all these patients.

In the first case, the elimination of the paresis of the ciliary muscle eliminates functional astigmatism and restores vision. In the second, the eye's strong accommodative ability compensates for organic astigmatism. In the third, improving the blood supply to the visual analyzer increases its function.

Have 55% nearsighted people have anisometropia (different refraction of two eyes). Sometimes one eye first outstrips the other in terms of myopia, and then vision levels out. It happens that the worst eye becomes the best. Comparison of the degree of refraction with the state of cerebral hemodynamics revealed a clear correlation between the magnitude of myopia and the volumetric blood flow in the VBV vessels.

PAs are at a small distance from each other, but with dislocation of the cervical vertebrae they can suffer to varying degrees. This explains the frequent anisometropia. Interestingly, ophthalmologists note that more often the degree of myopia is higher in the right eyes (according to our data, in 58% patients, according to I.L. Ferfilfayn - in 61,7%), and pediatric neuropathologists and pathologists consider right PAs more vulnerable and more likely to suffer from compression.

The accommodative function of the eyes

The state of the accommodative function of the eyes in myopic people is given special importance, since it is the weakness of accommodation under conditions of intense visual load that is the first link in the three-factor theory of the pathogenesis of the development of myopia according to E.S. Avegisov. Among all indicators of the function of the ciliary muscle, the positive part, or ZOA, is of greatest importance. Professor E.S. Avetisov believed that it is the decrease in the value of the ZOA that is the closest criterion for the threatening progression of myopia.

As you know, to determine the state of relative accommodation of the eyes, it is necessary to insert lenses into the patient's frame that optimally correct his vision for distance. Then at a distance 33 see the doctor shows him the text №4 (visual acuity 0,7 ) tables for testing eyesight at close range. If the patient can read it, first negative glasses are inserted alternately over the glasses correcting his ametropia until the patient stops seeing him.

The last negative glass, with which reading is still possible, is an indicator of the size of the accommodation reserves or the positive part of the relative accommodation. The negative (spent) part of it is defined similarly. The maximum positive lens with which the patient reads the reference text corresponds to this indicator. As a rule, if all the conditions for the study of accommodation are met, the negative part is +3,0 diopters. It is by this value that the refraction of the eye should increase during convergence at a distance 33 cm ( 100cm: 33cm \u003d 3.0 ).

For progressive myopia, a decrease in the OVA is characteristic in comparison with the age norm. Usually, to assess this indicator, we are guided by the data of the N.I. Helmholtz. ZOA are:

at 7-10 years - 3,0 diopters, in 11-12 - 4,0 dp gr, v 13-20 - 5,0 diopters, 21-25 - 4.0 diopters, 26- 30 - 3.0 diopters. 31-35 - 2,0 diopters, 36-40 - 1,0 diopter, older 40 years - 0 diopters.

In patients with myopia, both accommodation for the distance (therefore, they begin to see poorly into the distance) and for the near suffers. However, it is the violation of the contractile function of the ciliary muscle that leads to the need to turn on the vicious mechanism of focusing closely located objects by bringing them closer to the eyes and lengthening the PZO of the eye.

If the accommodative function of the eyes is restored before the appearance of its axial deformation (and a myopic scleral sickle forms around the optic nerve head from the temporal side), then visual acuity will also be fully restored. This myopia is called functional or "false" myopia. Previously, it was explained by the spasm of accommodation and was "treated" with atropine.

In functional myopia, the BTYAZ is removed due to a decrease in the contractile capacity of the ciliary muscle, and in organic myopia, due to lengthening of the PZO of the eye, it approaches the eye. TYAZ is approaching in both cases. Therefore, in functional myopia, the volume of absolute accommodation is less than in organic myopia.

As mentioned in the previous chapter, paresis of accommodation in nearsighted people is most often one of the symptoms of nuclear paresis of the oculomotor nerve. Therefore, with a macroscopic examination of the eyes, it is often possible to detect a slight asymmetry in the position of the upper eyelids, anisocoria, a smaller range of movements of one eyeball compared to the other. Convergence often suffers.

When trying to focus on an approaching finger, one or both eyes move outward. Muscle imbalance leads to heterophoria. Most typical for eyes with progressive myopia is the inferiority of the internal, lower and, somewhat less often, of the external rectus muscles.

Therefore, most often exophoria is observed, less often inforia. Interestingly, all the symptoms of paresis of the oculomotor muscles (especially ptosis, mydriasis and impaired accommodation) are most pronounced at low illumination. This is due to the existence of a reflex arc between the optic and oculomotor nerves (direct and friendly pupillary reactions).

To illustrate, I will give an example from my own practice. Once, during an ophthalmological examination of a child who was being treated in a children's neurological clinic for chronic cerebral vascular insufficiency, I noted that he had more pronounced ptosis and mydriasis of one eye. Other symptoms of paresis were present at the same time. III pairs of FMN in both eyes.

The next day, the boy was brought to a consultation with Professor A.Yu. Ratner, and he did not find any of the symptoms I described. When I was invited to re-examine the child, the professor's office, where the consultation took place, was flooded with bright sunlight. Looking at the patient, I, to my shame, also did not see any ptosis or anisocoria in him and agreed with neuropathologists that I allowed overdiagnosis.

However, as soon as I brought the child back to the dark room, where traditionally ophthalmologists watched the children, all these disappeared symptoms reappeared. Only then it became obvious that it was the lowered illumination that could help to reveal the minimal phenomena of nuclear paresis of the oculomotor nerve.

Thus, light is a powerful stimulator of the function of the oculomotor nerve. That is why it is so harmful for patients with weakened accommodation to practice in the dark.

Biomicroscopy of myopic eyes

Examination of the conjunctiva of the eyeball under a slit lamp reveals a whole complex of symptoms indicating a violation of the regional hemodynamics of the eye.

The anterior segment is usually not changed, although the size of the pupils, due to the hypofunction of the sphincter, is noteworthy.

As a rule, in young patients, when myopia progresses, no changes in the lens and vitreous are noted. Brown cataract and destruction of the vitreous body, so typical for myopia, appear after forty years. Changes in the vitreous body are characteristic of high myopia and are dystrophic in nature. When examining the patient under a slit lamp in the vitreous, filamentous destruction with floating flakes and diffuse opacities in the liquefied substrate is visible. Individual cavities filled with liquid can be biomicroscopic. Initially, these changes are localized in the posterior part of the eyeball, and then spread to the entire vitreous body.

The destruction of the vitreous body in some cases leads to its detachment. In this case, the posterior borderline membrane breaks off from its place of fixation around the optic nerve and floats in front of it in the form of a circular ring. Vitreous detachment is best seen when viewed with a Goldman lens under a silk lamp. The detached posterior membrane resembles a translucent curtain, separated from the retina by a dark optical sheath filled with liquid.

The cause of changes in the vitreous body, apparently, on the one hand, is axial stretching of the posterior parts of the eyeball, and on the other, regional ischemia of the eye and metabolic disorders, synthesis of mucopolysaccharides and other changes in metabolism associated with ischemia of the hypothalamic-pituitary region.

Condition of the optic nerve and retinal vessels

Features of the fundus in acquired myopia depend on the severity and severity of hemodynamic disturbances in the vessels of the orbital artery. The color of the optic disc is determined by the state of the capillary network covering it, extending from the retinal vessels. Therefore, with spasm of the orbital artery and retinal vessels, the disc color becomes paler, especially its temporal half.

Often, with severe vascular disorders, a slight blurring of the nasal boundaries appears. Such symptomatology was described by the associate professor of our department V.M. Krasnova and A.Yu. Ratner in patients with cervical osteochondrosis during its exacerbation and intensification of cerebral vascular insufficiency. For the differential diagnosis of such vascular changes in the optic nerve head with incipient atrophy of the optic nerve, it is necessary to conduct an ophthalmoscopy of the fundus using the Vodovozov method in purple light.

With true aphophia, the disc acquires a more pronounced blue color, and with symptomatic pallor it remains pink. It is characteristic that the field of view for white light can be concentrically narrowed in both cases. We explain this in patients with myopia, spasm of retinal vessels and hypoxia of the peripheral retina. Examination of the visual field for red light reveals a significant increase in concentric narrowing in patients with optic nerve atrophy, in contrast to patients with symptomatic pallor.

The study of the critical flicker fusion frequency (CFF) and visual evoked potentials (VEP) helps to assess the functional state of the optic nerve and the visual analyzer even more subtly. Studies of our graduate student G.R. Tazieva revealed in children with mild and moderate myopia a significant decrease in CFFS and VEP amplitudes while maintaining normal latent time parameters. These changes were somewhat more frequent in patients with moderate myopia, but they correlated even more clearly with the state of cerebral hemodynamics.

It is interesting that exactly the same deviations in the VEP parameters were observed by her in emmetropes with chronic cerebral vascular insufficiency. It is important to note that such electrophysiological symptoms of "vascular" pathology in patients with myopia were observed along the entire path of the visual analyzer.

Apparently, this explains the decrease in corrected visual acuity in some of these patients and, possibly, the narrowing of the visual field. At the same time, the professing of these vascular disorders of the optic nerve and the analyzer can explain the rather high frequency of optic nerve aphophy, which develops in myopic patients at an older age.

In the practice of ophthalmologists, the opinion has already been established that narrowing of the vessels of the central retinal artery is the norm in myopic eyes. Meanwhile, working with neuropathologists, we drew attention to their extremely scrupulous attitude to the state of the caliber of the retinal vessels. In this situation, of course, our colleagues are right.

The fact is that our description of the fundus and, especially, the state of the arteries and veins helps them to differentiate, for example, vascular headaches with hypertensive ones. The former are characterized by spasm of the retinal arteries and pallor of the optic nerve head, slight blurring of its fanits, and for the latter, the phenomenon of venous stasis with dilation and tortuosity of veins, a picture of congestive nipple.

In the clinic, the diagnosis, of course, is facilitated by additional research methods - DG, REG. echoencephalopathy, X-ray of the skull. Comparison of all the data convinces of the high information content of the fundus picture to explain the nature of cerebral pathology. We consider spasm of retinal vessels to be normal in myopia only on the basis of the high frequency of these symptoms in nearsighted people. The real reason for this phenomenon, as our studies have shown, is a compensatory spasm of the orbital arteries in the event of the SA steal syndrome, which develops in response to a reduction in blood flow in the C B B system.

Previously, ophthalmologists tried to explain the narrowing of the retinal vessels with myopia by a stronger refraction of the eye, which, with reverse ophthalmoscopy, led to a decrease in all details of the fundus, including the caliber of the vessels.

Other authors believed that this symptom is due to the stretching of the retinal vessels simultaneously with the stretching of the membranes of the eyeball in high myopia. However, OG Levchenko proved that regional eye disorders and vasoconstriction of the retina appear already at the earliest stages of myopia, when there can be no question of a significant increase in refraction or stretching of the eyeball.

Our research has revealed that 450 in children with mild myopia, narrowing of the retinal arteries was 236 man ( 52,4%), of 216 patients with moderate myopia - in 132 (61,1%). Other researchers have also noted a slight increase in the number of patients with spasm of the retinal arteries as the refraction of the eye increases.

Our analysis of the results of rheoencephalographic and ophthalmoscopic correlations also showed that retinal vasoconstriction occurs in patients with a decrease in volumetric blood flow in the ICA and VA. At the same time, these children develop headaches and become more frequent and the accommodative function of the eyes weakens, which results in the progression of myopia. Therefore, this symptom in the fundus should be considered as a manifestation of cerebral vascular insufficiency and a harbinger of the progression of myopia.

In addition to changing the caliber of the arteries, the diameter of the veins changes in some cases. Expansion of the retinal veins was observed in 28,4% children with mild myopia and 26,4% patients with moderate myopia. This symptom is characteristic of patients with hypotension and mild venous outflow disturbances. Often in the fundus of patients with myopia, manifestations of VSD in the form of different caliber of retinal arteries in one eye can be noted.

Myopic scleral sickle, cone and staphyloma

As a rule, the development of mild myopia is accompanied by the appearance of a myopic sickle, bordering the optic nerve from the temporal side and having a width of up to 1/3 DC. Enhancing refraction by 3 diopters are associated with lengthening the PZO of the eye by 1 mm. Therefore, the stretch zone of the sclera around the optic nerve is still insignificant. However, there may be dissociation of this symptom with the degree of myopia. For example, the absence of a scleral sickle with myopia - 3,0 diopters or, conversely, the presence of a scleral cone with a width of 1/3 DD of the optic nerve.

This discrepancy is due to the initial refraction and the associated shape of the eyeball.

The first option (the absence of a sickle) is typical for children with hereditary myopia due to the large size of the eyeball. As a rule, there is no axial lengthening of the eye and ultrasound echobiometry indicates that the normal proportions of the eyeball are maintained when the PZO is less than the horizontal one. With this variant of myopia, there will be no other symptoms of stretching of the choroid of the eye, characteristic of complicated myopia.

The second option, when the myopic cone is too large for a given degree of myopia, develops in children who initially had hyperopic refraction. It's no secret that similar "myopic" temporal scleral sickles can be found in hyperopes. The nature of their development is exactly the same as in the progression of myopia. Only in this case there is not an increase in myopia, but a decrease in the degree of hyperopia.

Patients who have crossed the zero refractive mark then become myopic. Naturally, the degree of axial lengthening of the eye in them will be greater than in children with initial emmetropic refraction, and the complications will correspond to a greater degree of myopia. In our practice, there were patients who have moderate hyperopia detected in 6 -years old, to 10 years gave way to myopia.

It is clear that not a single experienced doctor can share the joy of mothers about such a rapid "getting rid" of hyperopia, since it is accompanied by stretching of the membranes of the eye and promises only complications. Naturally, such patients with a rapid decrease in the degree of hyperopia (and they also have visual loads disproportionate to weakened accommodation and inferiority of cerebral hemodynamics) should be treated according to all principles of therapy for progressive myopia.

As a rule, in patients with initial manifestations of myopic changes in the fundus (series to 1/3 DC) in childhood there is no other pathology. However, with age, vascular disorders can progress and cause dyspigmentation in the macular region, the disappearance of the macular reflex, and subsequently lead to other central chorioretinal dystrophies (CCRD) and peripheral vitreochorioretinal dystrophies (VVHD) of vascular genesis. The development of the latter explains the possibility of retinal tears and detachment in eyes with low myopia.

Further progression of axial lengthening of the eye leads to the development of a small cone around the optic nerve, the width of which does not exceed 1/2 DD, then the middle cone - up to 1 DD and a large cone whose width exceeds 1 DD. In this case, the optic nerve head can acquire an inclined, oblique position. Pronounced axial elongation also leads to the so-called supertraction of the membranes from the inner side of the eye.

With high myopia, the entire optic nerve head is located in the depression formed by the stretched sclera. This is myopic staphyloma.

It can capture the entire posterior pole of the eye, leading to gradual vascular atrophy of the choroid. First, the choriocapillaries disappear, and then the medium and large vessels. The border of the staphyloma is visible in the form of an arcuate line through which the retinal vessels are bent, concentrically located in relation to the optic nerve head.

Cone)

a sickle-shaped formation on the fundus found during ophthalmoscopy, adjacent directly to the edge of the optic nerve head; observed with myopia due to stretching of the sclera and atrophy of the retina and choroid near the disc.

1. Small Medical Encyclopedia. - M .: Medical encyclopedia. 1991-96 2. First aid. - M .: Great Russian Encyclopedia. 1994 3. Encyclopedic Dictionary of Medical Terms. - M .: Soviet encyclopedia. - 1982-1984.

See what "Myopic Cone" is in other dictionaries:

- (conus myopicus; syn.: posterior cone, cone), a sickle-shaped formation on the fundus detected by ophthalmoscopy, adjacent directly to the edge of the optic nerve head; observed with myopia due to stretching of the sclera and atrophy ... ... Big Medical Dictionary

1) (Conus) in zoology, the genus of poisonous mollusks, fam. real snails inhabiting Ch. arr. in tropical seas; K.'s bite causes severe intoxication in a person; 2) in ophthalmology, see Myopic cone ... Big Medical Dictionary

Big Medical Dictionary

- (conus posterior) see Myopic cone ... Medical encyclopedia

1) (Conus) in zoology, a genus of poisonous molluscs of the family of real snails, living mainly in tropical seas; K.'s bite causes severe intoxication in a person; 2) in ophthalmology, see Myopic cone ... Medical encyclopedia

MYOPIA - Myopia, myopia (from the Greek.myo squinting and ops eyes; it has long been noticed that squinting eyes, myopic people see better), refractive error (see), with a swarm, the disparity of the length of the eye with its refractive power is expressed in the prevalence of the first over ... ... Great medical encyclopedia

I Nearsightedness (myopia; synonym for myopia) is an abnormality of refraction of the eye, in which parallel rays of light entering the eye, after refraction, converge in focus not on the retina, but in front of it. This may depend on the refractive system ... ... Medical encyclopedia