60. What anatomical structures pass through the superior orbital fissure?
All oculomotor nerves (oculomotor, blocky, abducens), 1 branch of the trigeminal nerve (optic nerve), superior orbital vein pass through the superior orbital fissure.
61. List the main clinical signs of the superior orbital fissure syndrome.
With damage to the bones of the orbit, the so-called "Superior orbital fissure syndrome". In this case, symptoms of damage to the nerves and blood vessels passing through the superior orbital fissure (see above) will be observed: 1. Complete paralysis of all muscles of the eyeball (complete ophthalmoplegia) 2. Ptosis of the upper eyelid (ptosis) 3. Mydriasis - pupil dilation 4. Disorder sensitivity of the skin of the eyelids, conjunctiva and cornea (damage to 1 pair of trigeminal nerve) 5. Mild exophthalmos (retrobulbar hematoma due to damage to the superior orbital vein)
Section II. Refraction.
62. Indicate visual acuity if the subject sees the 10th line of the Sivtsev table from a distance of 3.5 m.
According to the Snellen formula, V = d / D. V - visual acuity d - distance from which the patient sees line 10 (3.5 m) D - distance from which the patient should see line 10 (5 m) Thus, V = 3.5 /5 = 0.7 Therefore, the subject's visual acuity is 0.7
63. A 70-year-old patient has a visual acuity of 1.0. Is it possible to judge the type of clinical refraction on the basis of these data? If so, what kind of refraction are we talking about?
Yes, you can. If the patient's visual acuity is 1.0, this means that his refraction is emmetropia or hyperopia (due to the tension of accommodation at a young age with hyperopia, visual acuity may be normal). However, in this case (a 70-year-old patient), the volume of accommodation is zero, hence the only possible option is emmetropia.
64. Are glasses for nearness necessary for a person at the age of 55 with 2.5 d hyperopia in both eyes? If so, write a prescription.
Yes, we do.
Rp .: Reading glasses.
Ou Sph + 5.0 Diopters
65. Is there a surgical treatment for progressive myopia? If so, what is the operation?
Yes, it does. With progressive myopia, an operation is performed, aimed at strengthening the posterior segment of the eye. Canned autofascia strips or homosclera are passed along the posterior pole of the sclera and sutured 5-6 mm from the limbus. After engraftment of grafts, the sclera in the posterior pole thickens, which prevents its further stretching.
66. In the study of clinical refraction in the vertical meridian revealed hyperopia 1.0 D, and in the horizontal - hypermegropia 2.5 D. Write a detailed diagnosis of this condition. H 1.0 D
Complex hyperopic astigmatism
H 2.5 D direct type (vertical refraction
the meridian is stronger).
67. What is the patient's visual acuity if he distinguishes the details of the signs of the first row of Sivtsev's table from a distance of 1.5 m?
V = d / D = 1.5 / 50 = 0.03
68. Write out near glasses for a 70-year-old patient who has 2.0D hyperopia in both eyes.
Rp .: Reading glasses.
Ou Sph + 5.0 Diopters
69. O What factors does the volume of accommodation depend on?
The main factor determining the amount of accommodation is age the patient. With age, physiological involutional processes occur in the lens, which are expressed in the densification of its tissue, which leads to a gradual decrease in the volume of accommodation.
Increase in myopia by 1.0 Diopters and more throughout the year.
71. Give a definition of the concept of "astigmatism".
Astigmatism - combination in one eye of different types of refraction or different degrees of one type of refraction.
72. If the examined person has a visual acuity of 0.01, then from what maximum distance can he count the fingers of your hand?
V = d / D, therefore d = V x D V = 0.01 D = 50 m (since the thickness of the fingers roughly corresponds to the thickness of the characters in the first line of Sivtsev's table) Thus, d = V x D = 0.01 x 50 m = 0.5 m. The subject will be able to count his fingers from a distance of 50 cm.
73. How old is a patient who, having a hyperopia of 1.0 D, uses spherical glasses of +2.0 D for near?
In this case, +1.0 D spherical glasses are required to correct hyperopia. An additional +1.0 D is needed to correct presbyopia. Thus, the volume of accommodation in this patient is reduced by 1.0 D, which corresponds to the approximate age of 40 years.
74. Is there a relationship between age and the position of the further point of view?
No. The position of the further point of clear vision depends only on the type of clinical refraction.
75. Indicate the type of the most acceptable correction of high degree anisometropia.
Contact correction.
76. What can be the cause of incorrect astigmatism?
Irregular astigmatism is characterized by local changes in refractive power on different segments of the same meridian. The causes of incorrect astigmatism are most often corneal diseases: trauma, scars, keratoconus, etc.
77. Are near glasses necessary for a patient at the age of 50 who has myopia 2.0 D in both eyes? If so, write a prescription.
No, they are not needed. For the correction of myopia, glasses of -2.0 D are required, and for the correction of presbyopia at this age - glasses of +2.0 D. Therefore, glasses are not needed.
78. List the indications for the appointment of bifocal glasses.
Moderate to high myopia and hyperopia in the elderly.
79. What medications can impair near vision. Why?
The impairment of near vision is associated with accommodation paralysis. Accommodation paralysis can be caused by atropine-like drugs (anticholinergics).
80. On the figure of the cross, give an example of mixed astigmatism.
With mixed astigmatism, there is myopia in one meridian, hyperopia in the other:
M 1.0 D H 2.0 D
81. A spherical positive lens has a main focal length of 50 cm. What is its optical power?
D = 1 / F = 1 / 0.5 = 2.0 D
82. Can a person at the age of 25 with a hyperopia of 2.5 D have visual acuity equal to 1? If so, what are the factors?
Yes maybe. Due to the tension of accommodation (an increase in the curvature of the lens) with a weak degree of hyperopia at a young age, the rays can be focused on the retina and the distance vision does not suffer.
83. Write a prescription for near glasses for a 60-year-old patient who has 1.0D myopia in both eyes?
Rp .: Close up glasses
Ou Sph + 2.0 Diopters
84. If it becomes necessary to correct anisometropia with spherical glasses, what is the basic principle that should be followed?
Basic principle: the difference in refractive power between spherical glasses for different eyes should not exceed 2.0 D.
85. What is the main difference between a spherical stack and a cylindrical one?
Spherical glass refracts rays of light equally in all meridians (directions), while cylindrical glass refracts rays only in a plane perpendicular to the axis of the cylinder. Due to this feature, cylindrical glasses are used in the correction of astigmatism.
86. What is the refractive power of the cornea?
87. Can a person at the age of 65 with 2.5 D hyperopia have a visual acuity of 1? Why?
No, it cannot, since the volume of accommodation after 60 years is zero (that is, there is practically no accommodation). Therefore, the eye cannot, by increasing the curvature of the lens, focus the light beams on the retina, and they are focused behind the retina (since the patient has hyperopia).
88. A 72-year-old patient has a myopia of 2.0 D in both eyes. The optical media are transparent, the fundus is normal. Write a prescription for glasses.
Rp .: Glasses for distance Rp .: Close up glasses
Ou Sph -2.0 Diopters Ou Sph +1.0 Diopters
Dр = 64 mm Dр = 62 mm
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The syndrome of the superior orbital fissure is a pathology characterized by complete paralysis of the internal and external muscles of the eye and loss of sensitivity of the upper eyelid, cornea, and part of the forehead. Symptoms can be caused by damage to the cranial nerves. Painful conditions arise as complications of tumors, meningitis and arachnoiditis. The syndrome is typical for elderly and middle-aged people; such a pathology is rarely diagnosed in a child.
Anatomy of the apex of the orbit
The orbit, or orbit, is a paired bony notch in the skull that is filled with the eyeball and its appendages. Contains structures such as ligaments, blood vessels, muscles, nerves, lacrimal glands. The apex of the cavity is called its deep zone, bounded by the sphenoid bone, which occupies about a fifth of the entire orbit. The boundaries of the deep orbit are outlined by the wing of the main bone, as well as by the orbital process of the palatine plate, the infraorbital nerve and the inferior orbital fissure.
Orbit structure
The eye socket is represented by three zones, each of which is limited by nearby structures.
- Outdoor. Formed by the zygomatic bone below, the upper jaw (its frontal process), the frontal, lacrimal, nasal and ethmoid bones.
- Inner area. It originates from the anterior end of the inferior orbital fissure.
- Deep zone or top of the orbit. It is limited to the so-called main bone.
Holes and slots
The apex of the orbit is associated with the following structures:
- wedge-shaped frontal suture;
- external geniculate body;
- wedge-zygomatic suture;
- small and large wings of the main bone;
- wedge-shaped lattice seam;
- main bone;
- palatine bone;
- the frontal process of the upper jaw.
Deep orbit has such holes:
- visual opening;
- lattice holes;
- round hole;
- infraorbital groove.
Deep orbit slots:
- lower orbital;
- upper orbital fissure.
Large nerves and blood vessels pass through the holes and through the cracks into the cavity of the orbit.
Causes of the syndrome
The supraorbital fissure syndrome can be caused by the following factors:
- Mechanical damage, eye injury.
- Tumors localized in the brain.
- Inflammation of the arachnoid membrane of the brain.
- Meningitis.
- Contact with a foreign body in the eye area.
The onset of the symptom complex of the superior palpebral fissure syndrome is associated with damage to the nerves: oculomotor, abducers, block, ocular.
Risk factors for the pathogenesis of the disease include living in ecologically polluted regions, eating foods containing carcinogenic substances, prolonged exposure to ultraviolet rays on the eyes.
The main signs
The main manifestations and symptoms of pathology are:
- Ptosis of the upper eyelid with the inability to raise it, as a result of which there is a narrowing of the palpebral fissure of one eye. The cause of the anomaly is the damage to the nerve.
- Paralysis of the internal and external eye muscles (ophthalmoplegia). Lost motor activity of the eyeball.
- Loss of sensitivity of the eyelid skin.
- Inflammatory processes in the cornea.
- Pupil dilation.
- Forward displacement of the eyeball (so-called bulging).
- Expansion of the retinal veins.
Some of the symptoms cause significant discomfort and are recorded by the patient, others are detected during examination by an ophthalmologist and further examination. The disease is characterized by a one-sided lesion with the preservation of the functions of the second, healthy, eye.
A combination of several signs or some of them indicate a pathological syndrome, while the lower orbital fissure remains unchanged.
In the photo, patients show asymmetry of the eyes, ptosis of the affected organ.
Diagnostics
Diagnosis of the disease is complicated by the fact that other ophthalmic problems have similar symptoms. The syndrome manifests itself in the same way as the following conditions:
- myasthenic syndromes;
- aneurysm of the carotid artery;
- multiple sclerosis;
- periostitis;
- temporal arteritis;
- osteomyelitis;
- parasellar tumors;
- neoplasms in the pituitary gland;
- tumor formations in the orbit.
To differentiate pathology from other diseases with similar manifestations, it is necessary to conduct diagnostic examinations in terms of ophthalmology and neurology:
- Collecting anamnesis with clarification of the nature of painful sensations and determination of the pathogenesis of the disease.
- Determination of visual fields and its acuity.
- Diaphanoscopy of the orbit (illumination method).
- Ophthalmoscopy.
- Radioisotope scanning (to identify tumor formations).
- Ultrasonography.
- Biopsy (if a tumor is suspected).
- Computed tomography of parts of the brain, disorders in which can provoke a symptom complex of the syndrome.
- Magnetic resonance imaging.
- Angiography (X-ray examination using a contrast agent).
After the detection of the first manifestations of the syndrome, an urgent consultation of specialists is required: an ophthalmologist and a neurologist. Since the pathology is caused by damage to structures that are located near the orbital fissure, therapy involves exposure to them in order to eliminate the root cause. Self-medication can lead to an aggravation of the condition and the inability to provide effective medical care.
The fundamental method in the treatment of the syndrome is immunosuppressive therapy, which stops the body's defense response in the case of the autoimmune nature of the disease. The low prevalence of pathology does not allow large-scale studies, however, an analysis of the available data allows us to conclude that the use of corticosteroids is rational. The attending physician may appoint:
- "Prednisolone"
- "Medrol",
- other analogues.
The drugs are administered intravenously or taken orally in the form of tablets. The effect of such treatment appears already on the third or fourth day. If there is no improvement, chances are high that the disease has been misdiagnosed.
Further monitoring of the patient's condition is important, since the steroids used also help to eliminate the symptoms of diseases and conditions such as carcinoma, lymphoma, aneurysm, chordoma, pachymeningitis.
In addition to immunosuppressive therapy, there is a treatment of the symptom complex, which is designed to alleviate the patient's condition. Analgesics are prescribed in the form of drops and tablets, anticonvulsants.
Vitamin complexes are shown as fortifying agents. There is a reception of metabolic drugs to regulate metabolic processes in the affected structures of the eye.
If there is a negative effect on the upper region of the orbital fissure, which connects the middle cranial fossa with the orbit, the supraorbital fissure syndrome may appear. As a result of this process, the III, IV, VI nerves of the skull, the first branch of the V nerve are affected.
There is complete ophthalmoplegia and anesthesia in various parts of the eye - the cornea, upper eyelid, and homolateral half of the frontal part.
Causes of the syndrome
The onset of the syndrome is caused by a number of nerve lesions around the eye. Suffer from the negative impact:
- oculomotor;
- block;
- abducting;
- ocular nerves.
The syndrome can occur as a result of mechanical damage to the eye, as well as become a consequence of various diseases in the human body:
Symptoms of the disease
The syndrome of the superior orbital fissure is characterized by the following symptoms:
The symptoms of the syndrome may not be fully detected. It depends on the extent and amount of nerve damage. If the patient feels two or more alarming signs, it is necessary to urgently visit a doctor for examination.
Diagnosis of the syndrome
Diagnosis of the syndrome is difficult due to the similarity of its symptoms to other diseases. The appearance of signs noted in the syndrome may be due to the manifestations:
- parasellar and tumors of the middle fossa of the skull, pterygoid bone, pituitary gland;
- retrobulbar volumetric processes;
- aneurysms of the carotid artery;
- periostitis;
- osteomyelitis, etc.
Also, the symptomatology is typical for diseases of the thyroid gland, temporal arteritis, meningitis,. All diseases can become a source of ophthalmoplegia as a result of nerve dysfunction in the cranial region.
Therefore, when contacting a medical facility, a patient needs to undergo a diagnosis. At the first stage, an examination by an ophthalmologist is shown. He examines the fields and visual acuity, the state of the fundus.
After examining the eyes, a neurologist is involved in the work. The doctor interviews the patient during the history taking. A detailed inspection is also shown.
Among the methods of instrumental diagnostics, there are:
- (computed tomography) of the brain and sella turcica;
- (magnetic resonance imaging) of the brain and sella turcica.
- also held angiography and echography.
If during the diagnosis during the MRI examination, granulomatous inflammation of the outer wall of the cavernous sinus is detected, then Tholos-Hunt syndrome is diagnosed.
A biopsy is done to confirm the result. In the absence of granulomas, the diagnosis of superior orbital fissure syndrome is made.
Methods of therapy and prevention
The syndrome is treated with immunosuppressive therapy. In studies conducted when choosing a therapy for this disease, corticosteroids have shown the highest efficiency. 
When diagnosing the syndrome, the patient can be assigned Prednisolone, as well as a drug with a similar effect, Medrol. When taking tablets, a dosage of 1 to 1.5 mg is observed, depending on the patient's body weight (the indicated dosage is multiplied by the number of kg). Also, the medicine is administered intravenously. A daily dose of 500 to 1000 mg is indicated.
The result after the use of steroids is assessed after 3 days. If the diagnosis is correct, the symptoms should disappear. However, the drug helps to reduce symptoms that are also manifested in:
- pachymeningitis;
- chordoma;
- lymphoma;
- aneurysm;
- carcinoma.
Therefore, it is important to make a correct diagnosis so that the treatment is carried out in the direction of its elimination. Also, during symptomatic therapy, analgesics and anticonvulsants are used to reduce pain. The intake of general metabolic agents and vitamins is shown to strengthen all body systems.
Preventive measures are applied depending on the disease that provoked the superior orbital fissure syndrome. If the syndrome is caused by trauma, then further damage to the eye should be avoided. This can lead to irreversible consequences.
The main rule after the onset of the syndrome is an emergency consultation with an ophthalmologist and a neurologist. They will help diagnose the disease in time and prevent complications by prescribing therapy.
With a horizontal dimension of 40 mm, and vertical - 32 mm(fig. 2.1.3).
The largest part of the outer edge (margo lateralis) and the outer half of the bottom edge (margo infraorbitalis) the orbit is formed by the zygomatic bone. The outer edge of the orbit is rather thick and can withstand heavy mechanical stress. When a bone fracture occurs in this area, it usually goes along
Rice. 2.1.3. Bones that form the orbit:
/ - orbital process of the zygomatic bone; 2 - cheekbone; 3 - the frontal-wedge-shaped process of the zygomatic bone; 4 - the orbital surface of the greater wing of the sphenoid bone; 5 - large wing of the sphenoid bone; 6 - the lateral process of the frontal bone; 7 - fossa of the lacrimal gland; 8 - frontal bone; 9 - visual opening; 10 - supraorbital notch; // - block hole; 12 - ethmoid bone; 13 - nasal bone; 14 - the frontal process of the upper jaw; 15 - the lacrimal bone; 16 - upper jaw; 17 - infraorbital opening; 18 - palatine bone; 19 - the inferior orbital groove; 20 - lower orbital fissure; 21 - zygomatic-facial opening; 22 -superorbital fissure
lines of distribution of seams. In this case, the fracture occurs both along the line of the zygomatic-maxillary suture in the direction downward or downward-outward along the line of the zygomatic-frontal suture. The direction of the fracture depends on where the traumatic force is applied.
The frontal bone forms the upper edge of the orbit (margo supraorbitalis), and its outer and inner parts are involved in the formation of the outer and inner edges of the orbit, respectively. In newborns, the upper edge is sharp. It remains acute in women throughout their lives, and in men it becomes more pronounced with age. On the upper edge of the orbit from the medial side, the supraorbital notch is visible (incisura frontalis), supraorbital nerve (n. supraorbitalis) and vessels. In front of the artery and nerve and slightly outward relative to the supraorbital notch is a small supraorbital foramen (foramen supraorbitalis), through which the artery of the same name penetrates into the frontal sinus and the spongy part of the bone (arteria supraorbitalis).
Inner edge of the orbit (margo medialis orbitae) in the anterior regions it is formed by the maxillary bone, which extends the process to the frontal bone.
The configuration of the inner edge of the orbit is complicated by the presence of lacrimal ridges in this area. For this reason, Whitnall suggests looking at the inner edge as a wavy spiral (Figure 2.1.3).
The lower edge of the orbit (margo inferior orbitae) formed by half of the maxillary and half of the zygomatic bones. The infraorbital nerve passes through the lower edge of the orbit from the inside. (n. infraorbitalis) and the artery of the same name. They come to the surface of the skull through the infraorbital foramen (foramen infraorbitalis), located somewhat whip and below the lower edge of the orbit.
2.1.3. Bones, walls and holes of the orbit
As indicated above, only seven bones form the orbit, which are also involved in the formation of the facial skull.
The medial walls of the eye sockets are parallel. They are separated from each other by the sinuses of the ethmoid and sphenoid bones. Lateral walls separate the orbit from the middle cranial fossa behind and from the temporal fossa in front. The orbit is located directly under the anterior cranial fossa and above the maxillary sinus.
The upper wall of the orbit(Paries superior orbitae)(fig. 2.1.4).
The upper wall of the orbit is adjacent to the frontal sinus and to the anterior cranial fossa. It is formed by the orbital part of the frontal bone, and behind it by the small wing of the sphenoid bone.
Bony formations of the orbit
Rice. 2.1.4. The upper wall of the orbit (by Reeh et al., 1981):
/ - orbital wall of the frontal bone; 2 - fossa of the lacrimal gland; 3 - front lattice hole; 4 - large wing of the sphenoid bone; 5 - upper orbital fissure; 6 - lateral orbital tubercle; 7 - block fossa; 8 - posterior crest of the lacrimal bone; 9 - anterior crest of the lacrimal bone; 10 - sutura notra
A wedge-shaped frontal suture runs between these bones. (sutura sphenofrontalis).
On the upper wall of the orbit, there are a large number of formations that play the role of "marks" used in surgical interventions. In the anterolateral part of the frontal bone is the fossa of the lacrimal gland (fossa glandulae lacrimalis). The fossa contains not only the lacrimal gland, but also a small amount of fatty tissue, mainly in the posterior part (accessory fossa Roch on-Duvigneaud). Below the fossa is limited by the zygomatic suture (s. fronto-zigomatica).
The surface of the bone in the area of the lacrimal fossa is usually smooth, but sometimes roughness is determined at the site of attachment of the lacrimal gland ligament.
In the anteromedial part, approximately at a distance of 5 mm from the edge, the block hole and block spine are located (fovea trochlearis et spina trochlearis), on the tendon ring of which the superior oblique muscle is attached.
The supraorbital nerve, which is a branch of the frontal branch of the trigeminal nerve, passes through the supraorbital notch, located on the upper edge of the frontal bone.
At the apex of the orbit, directly at the lesser wing of the sphenoid bone, there is an optic opening - the entrance to the optic canal (canalis opticus).
The upper wall of the orbit is thin and fragile. It thickens to 3 mm in the place of its formation by the small wing of the sphenoid bone (ala minor os sphenoidale).
The greatest thinning of the wall is observed in cases where the frontal sinus is extremely developed. Sometimes, with age, bone resorption of the upper wall occurs. In this case, periorbita contacts with the dura mater of the anterior cranial fossa.
Since the upper wall is thin, it is in this area that a bone fracture occurs with the formation of sharp bone fragments during trauma. Various pathological processes (inflammation, tumors) developing in the frontal sinus spread into the orbit through the upper wall. It is necessary to pay attention to the fact that the upper wall is on the border with the anterior cranial fossa. This circumstance is of great practical importance, since injuries to the upper wall of the orbit are often combined with brain damage.
Inner wall of the orbit(Paries me-dialis orbitae)(fig. 2.1.5).
The inner wall of the orbit is the thinnest (0.2-0.4 mm). It is formed by 4 bones: the orbital plate of the ethmoid bone (lamina orbitalis os ethmoi-dale), frontal process of the upper jaw (pro-cessus frontalis os zigomaticum), lacrimal bone
Rice. 2.1.5. Inner wall of the orbit (by Reeh et al., 1981):
1 - anterior lacrimal crest and frontal process of the upper jaw; 2 - lacrimal fossa; 3 - posterior lacrimal crest; 4 - lamina papyracea ethmoid bone; 5 - front lattice hole; 6 - the visual opening and the canal, the upper orbital fissure and spina recti lateralis; 7- the lateral angular process of the frontal bone; 8 - the lower orbital margin with the zygomatic-facial opening located on the right
Chapter 2. EYEBOX AND AUXILIARY EYE DEVICE
Tew and the lateral orbital surface of the sphenoid bone (fades orbitalis os sphe-noidalis), located the deepest. In the area of the suture between the ethmoid and frontal bones, the anterior and posterior ethmoid openings are visible (foramina ethmoidalia, anterius et pos-terius), through which the nerves and vessels of the same name pass (Fig. 2.1.5).
In the front of the inner wall, the lacrimal groove is visible (sulcus lacrimalis), continuing into the lacrimal sac (fossa sacci lacrimalis). The lacrimal sac is located in it. The lacrimal groove, as it moves downward, passes into the lacrimal-nasal canal (glanders nasolacrimalis).
The boundaries of the lacrimal fossa are outlined by two ridges - the anterior and posterior lacrimal ridges (crista lacrimalis anterior et posterior). The anterior lacrimal crest continues downward and gradually passes into the lower edge of the orbit.
The anterior lacrimal crest is easily felt through the skin and is a mark during operations on the lacrimal sac.
As indicated above, the main part of the inner wall of the orbit is represented by the ethmoid bone. Since of all the bone formations of the orbit, it is the thinnest, it is through it that the inflammatory process most often spreads from the sinuses of the ethmoid bone to the tissue of the orbit. This can lead to the development of cellulite, phlegmon of the orbit, thrombophlebitis of the veins of the orbit, toxic optic neuritis, etc. Children often experience acutely developing ptosis. The inner wall is also a site for the spread of tumors from the sinus to the orbit and vice versa. It is often destroyed during surgery.
The inner wall is somewhat thicker only in the posterior regions, especially in the region of the body of the sphenoid bone, as well as in the region of the posterior lacrimal crest.
The ethmoid bone, involved in the formation of the inner wall, contains numerous air-containing bone formations, which can explain the rarer occurrence of fractures of the medial wall of the orbit than the thick bottom of the orbit.
It should also be mentioned that in the area of the lattice suture, anomalies in the development of the bony walls often occur, for example, congenital "gaping", significantly weakening the wall. In this case, the defect in the bone tissue is covered with fibrous tissue. The weakening of the inner wall also occurs with age. The reason for this is the atrophy of the central portions of the bone plate.
In practical terms, especially when carrying out anesthesia, it is important to know the location of the anterior and posterior ethmoid openings through which the branches of the orbital artery pass, as well as the branches of the nasal ciliary nerve.
The anterior lattice openings open at the front end of the frontal-lattice suture, and the posterior ones - near the posterior end of the same suture (Fig. 2.1.5). Thus, the front holes are at a distance of 20 mm behind the anterior lacrimal crest, and the posterior ones at a distance of 35 mm.
The visual canal is located in the depth of the orbit on the inner wall. (canalis opti-cus), communicating the cavity of the orbit with the cranial cavity.
Outer wall of the orbit(Paries latera-lis orbitae)(fig. 2.1.6).
The outer wall of the orbit in its posterior part separates the contents of the orbit and the middle cranial fossa. In front, it borders on the temporal fossa (fossa temporalis), performed temporal muscle (i.e. temporalis). It is delimited from the upper and lower walls by the orbital fissures. These boundaries extend anteriorly to the wedge-frontal (sutura spheno-frontalis) and zygomatic-maxillary (sutura zi-gomaticomaxilare) seams (Fig.2.1.6).
The posterior part of the outer wall of the orbit forms only the orbital surface of the greater wing of the sphenoid bone, and the anterior part is the orbital surface of the zygomatic bone. Between them is the wedge-zygomatic suture (sutura sphenozigomatica). The presence of this suture greatly simplifies the orbitotomy.
Rice. 2.1.6. Outer wall of the orbit (by Reeh et al., 1981):
1 - frontal bone; 2 - large wing of the sphenoid bone; 3 - cheekbone; 4 - upper orbital fissure; 5 - spina recti la-teralis; 6- lower orbital fissure; 7 - the hole through which the branch passes from the zygomatic-orbital nerve to the lacrimal gland; 8 - zygomatic-orbital opening
Bony formations of the orbit
On the body of the sphenoid bone, at the junction of the wide and narrow parts of the upper orbital fissure, there is a small bony protrusion (thorn) (spina recti lateralis), from which the external rectus muscle begins.
On the zygomatic bone near the edge of the orbit is the zygomatic-orbital opening (/. zigomaticoorbitale), through which the branch of the zygomatic nerve leaves the orbit (n. zigomatico-orbitalis), heading to the lacrimal nerve. In the same area, an orbital eminence is also found. (eminentia orbitalis; Vitnell's orbital tubercle). Attached to it is the external ligament of the eyelid, the external "horn" of the levator, Lockwood's ligament (lig. suspensorium), orbital septum (septum orbitale) and lacrimal fascia (/. lacrimalis).
The outer wall of the orbit is the place of the simplest access to the contents of the orbit during various surgical interventions. The spread of the pathological process to the orbit from this side is extremely rare and is usually associated with diseases of the zygomatic bone.
When performing an orbitotomy, an ophthalmohirurg should know that the posterior edge of the incision is at a distance of 12-13 from the middle cranial fossa. mm in men and 7-8 mm among women .
The lower wall of the orbit(Paries inferior orbitae)(fig. 2.1.7).
The bottom of the orbit is at the same time the roof of the maxillary sinus. Such a neighborhood is important in practical terms, since in diseases of the maxillary sinus, the orbit is often affected and vice versa.
The lower wall of the orbit is formed by three bones: the orbital surface of the upper jaw (fades orbitalis os maxilla), occupying most of the bottom of the orbit, the zygomatic bone (os zigomaticus) and the orbital process of the palatine bone (processus orbitalis os zigomaticus)(fig. 2.1.7). The palatine bone forms a small area at the back of the orbit.
The shape of the bottom wall of the orbit resembles an equilateral triangle.
Between the lower edge of the orbital surface of the sphenoid bone (fades orbitalis os sphenoidalis) and the posterior edge of the orbital surface of the maxillary bone (fades orbitalis os maxilla) is the inferior orbital fissure (fissura orbitalis inferior). A line that can be drawn through the axis of the inferior orbital fissure forms the outer border of the inferior wall. The inner border can be determined along the anterior and posterior ethmo-maxillary sutures.
The infraorbital groove (groove) begins on the lateral edge of the lower surface of the maxillary bone (sulcus infraorbitalis), which, as we move forward, turns into a channel (canalis infraorbitalis). They are located
Rice. 2.1.7. The lower wall of the orbit (by Reeh et al., 1981):
I- lower orbital edge, maxillary part; 2 - infraorbital opening; 3 - the orbital plate of the upper jaw; 4 - lower orbital groove; 5 - the orbital surface of the large wing of the sphenoid bone; 6 - the marginal process of the zygomatic bone; 7 - lacrimal fossa; 8 - lower orbital fissure; 9 - the place of the beginning of the lower oblique muscle
infraorbital nerve lags (n. infraorbitalis). In the embryo, the infraorbital nerve lies loosely on the bony surface of the orbit, but gradually sinks into the rapidly growing maxillary bone.
The outer opening of the infraorbital canal is located under the lower edge of the orbit at a distance of 6 mm(fig. 2.1.3, 2.1.5). In children, this distance is much shorter.
The lower wall of the orbit has a different density. It is denser near and somewhat outside of the infraorbital nerve. The inside wall becomes noticeably thinner. It is in these places that post-traumatic fractures are localized. The lower wall is also the site of the spread of inflammatory and tumor processes.
Visual channel(Canalis opticus)(fig. 2.1.3, 2.1.5, 2.1.8).
The visual opening, which is the beginning of the visual canal, is located somewhat inside the upper orbital fissure. The section of the junction of the lower wall of the lesser wing of the sphenoid bone, the body of the sphenoid bone with its lesser wing, separates the visual opening from the upper orbital fissure.
The opening of the optic canal facing the orbit has dimensions of 6-6.5 mm in the vertical plane and 4.5-5 mm in the horizontal (Fig. 2.1.3, 2.1.5, 2.1.8).
The optic canal leads to the middle cranial fossa (fossa cranialis media). Its length is 8-10 mm. The axis of the visual canal is directed downward and outward. Rejection of this
Chapter 2. EYEBOX AND AUXILIARY EYE DEVICE
Rice. 2.1.8. Top of the eye socket (according to Zide, Jelks, 1985):
1 - lower orbital fissure; 2 - round hole; 3 - upper orbital fissure; 4 - the optic opening and the optic canal
axis from the sagittal plane, as well as downward, relative to the horizontal plane, is 38 °.
The optic nerve passes through the canal (item opticus), ocular artery (a. ophtalmica), immersed in the sheaths of the optic nerve, as well as the trunks of the sympathetic nerves. After entering the orbit, the artery lies below the nerve, and then crosses the nerve and is located outside.
Since the position of the ophthalmic artery changes in the embryonic period, the canal takes the form of a horizontal oval in the posterior section and a vertical oval in the anterior one.
By the age of three, the visual canal reaches its usual size. Its diameter is more than 7 mm it is already necessary to consider it a deviation from the norm and assume the presence of a pathological process. A significant increase in the visual canal is observed with the development of various pathological processes. In young children, it is necessary to compare the diameter of the optic canal on both sides, since it has not yet reached its final size. When detecting different diameters of the visual canals (at least 1 mm) one can quite confidently assume that there is an anomaly in the development of the optic nerve or a pathological process localized in the canal. In this case, gliomas of the optic nerve, aneurysms in the region of the sphenoid bone, and intraorbital spread of tumors of the optic chiasm are most often found. It is rather difficult to diagnose intratubular meningiomas. Any long-term optic neuritis may indicate the possibility of developing an intratubular meningioma.
A large number of other diseases lead to the expansion of the visual canal. These are benign hyperplasia of the arachnoid membrane, fungal lesions (mycoses), granulomatous inflammatory reaction (syphilitic gum, tuberculoma). Dilation of the canal also occurs in sarcoidosis, neuro-fibroma, arachnoiditis, arachnoid cyst and chronic hydrocephalus .
Narrowing of the canal is possible with fibrous dysplasia or fibroma of the sphenoid bone.
Superior orbital fissure(Fissura orbitalis superior).
The shape and size of the orbital fissure differ significantly from individual to individual. It is located on the outside of the visual opening at the apex of the orbit and has the shape of a comma (Fig. 2.1.3, 2.1.6, 2.1.8, 2.1.9). It is limited by the small and large wings of the sphenoid bone. The upper part of the superior orbital fissure is narrower on the lateral side than on the medial side and below. At the junction of these two parts is the spine of the rectus muscle (spina recti).
The oculomotor, trochlear nerves, I branch of the trigeminal nerve, the abducens nerve, the superior orbital vein, the recurrent lacrimal artery, the sympathetic root of the ciliary ganglion pass through the superior orbital fissure (Fig. 2.1.9).
Common tendon ring (anulus tendi-neus communis; zinn ring) is located between the upper orbital fissure and the visual
Rice. 2.1.9. Arrangement of structures in the region of the orbital fissure and Zinn ring (by Zide, Jelks, / 985):
1 - external rectus muscle; 2 -the upper and lower branches of the oculomotor nerve; 3 - frontal nerve; 4 - the lacrimal nerve; 5 - trochlear nerve; 6 - upper rectus muscle; 7 - nasal nerve; 8 - upper eyelid levator; 9 - upper oblique muscle; 10 - abducens nerve; // - internal rectus muscle; 12 - lower rectus muscle
Bony formations of the orbit
Channel. Through the Zinn ring, the optic nerve, the orbital artery, the superior and inferior branches of the trigeminal nerve, the nasal ciliary nerve, the abducens nerve, the sympathetic roots of the trigeminal ganglion enter and thereby are located in the muscle funnel (Fig. 2.1.8, 2.1.9).
The superior branch of the inferior optic vein passes immediately under the ring in the superior orbital fissure. (v. ophthalmica inferior). Outside the ring, on the lateral side of the superior orbital fissure, there is a trochlear nerve (n. trochlearis), superior ocular vein (v. ophthalmica superior), as well as the lacrimal and frontal nerves (pp. lacrimalis et frontalis).
The expansion of the superior orbital fissure may indicate the development of various pathological processes, such as aneurysm, meningioma, chordoma, pituitary adenoma, benign and malignant orbital tumors.
Sometimes an inflammatory process of an unclear nature develops in the area of the upper orbital fissure (Talas-Hant syndrome, painful ophthalmoplegia). It is possible that the inflammation spreads to the nerve trunks heading to the external muscles of the eye, which is the cause of the pain that occurs with this syndrome.
The inflammatory process in the area of the upper orbital fissure can lead to impaired venous drainage of the orbit. The consequence of this is swelling of the eyelids and orbit. Also described are tuberculous encephalic periostitis, spreading to structures located in the intraorbital fissure.
Inferior orbital fissure(Fissura orbitalis inferior)(fig. 2.1.7-2.1.10).
The inferior orbital fissure is located in the posterior third of the orbit between the bottom and the outer wall. Outside, it is bounded by the large wing of the sphenoid bone, and from the medial side by the palatine and maxillary bones.
The axis of the inferior orbital fissure corresponds to the anterior projection of the optic opening and lies at a level corresponding to the lower edge of the orbit.
The lower orbital fissure extends forward more than the upper orbital fissure. It ends at a distance of 20 mm from the edge of the orbit. It is this point that is the reference point for the posterior border during subperiosteal bone removal of the lower wall of the orbit.
The pterygopalatine fossa is located immediately below the inferior orbital fissure and on the outside of the orbit. (fossa pterygo-palatina), and in front - the temporal fossa (fossa temporalis), performed by the temporal muscle (Fig. 2.1.10).
Blunt trauma to the temporalis muscle can lead to bleeding into the orbit as a result of the destruction of the vessels of the pterygopalatine fossa.
Rice. 2.1.10. The temporal, infratemporal and pterygopalatine fossa:
/ - temporal fossa; 2 - pterygopalatine fossa; 3 - oval hole; 4 - pterygopalatine opening; 5 - lower orbital fissure; 6 - eye socket; 7 - cheekbone; 8 - alveolar process of the upper jaw
A round opening is located behind the inferior orbital fissure in the greater wing of the main bone (foramen rotundum), connecting the middle cranial fossa with the pterygopalatine fossa. Branches of the trigeminal nerve, in particular the maxillary nerve, penetrate through this opening into the orbit. (n. maxillaris). When leaving the opening, the maxillary nerve gives off a branch - the infraorbital nerve (p. infraorbi-talis), which, together with the infraorbital artery (a. infraorbitalis) penetrates into the orbit through the inferior orbital fissure. Further, the nerve and artery are located under the periosteum in the infraorbital sulcus (sulcus infraorbitalis), and then pass into the infraorbital canal (foramen infraorbitalis) and come out to the front surface of the maxillary bone at a distance of 4-12 mm below the middle of the edge of the orbit.
Through the inferior orbital fissure from the infratemporal fossa (fossa infratemporalis) the zygomatic nerve also penetrates the eye socket (n. zigo-maticus), minor branch of the pterygopalatine ganglion (g an g- sphenopalatina) and veins (lower ocular) that drain blood from the orbit into the pterygoid plexus (plexus pterygoideus).
In the orbit, the zygomatic nerve is divided into two branches - the zygomatic-facial (zigomaticofacialis) and zygomatic-temporal (n. zigomaticotemporalis). Subsequently, these branches penetrate into the channels of the same name in the zygomatic bone on the outer wall of the orbit and branch out in the skin of the zygomatic and temporal regions. From the zygomatic-temporal nerve towards the lacrimal gland,
Chapter 2. EYEBOX AND GAS AUXILIARY APPARATUS
The nerve trunk, which carries the secretory fibers, lies.
The inferior orbital fissure is closed by Müller's smooth muscle. In lower vertebrates, contracting, this muscle leads to protrusion of the eye.
The orbit, or bony orbit, is a bony cavity, which is a reliable protection for the eyeball, the auxiliary apparatus of the eye, blood vessels and nerves. The four walls of the orbit: upper, lower, external and internal, are firmly connected to each other.
However, each of the walls has its own characteristics. So, the outer wall is the most durable, and the inner one, on the contrary, collapses even with blunt injuries. A feature of the upper, inner and lower walls is the presence of air sinuses in the composition of the bones that form them: frontal from above, ethmoid labyrinth inside and maxillary sinus from below. Such a neighborhood often leads to the spread of inflammatory or tumor processes from the sinuses into the cavity of the orbit. The orbit itself is connected to the cranial cavity through numerous openings and slits, which is potentially dangerous when the inflammation spreads from the orbit to the side of the brain.
Orbit structure
The shape of the orbit resembles a tetrahedral pyramid with a truncated apex, having a depth of 5.5 cm, a height of 3.5 cm and a width of the entrance to the orbit of 4.0 cm. Accordingly, the orbit has 4 walls: upper, lower, internal and external. The outer wall is formed by the sphenoid, zygomatic and frontal bones. It separates the contents of the orbit from the temporal fossa and is the most durable wall, so that the outer wall is rarely damaged in case of injury.
The upper wall is formed by the frontal bone, in the thickness of which, in most cases, the frontal sinus is located, therefore, with inflammatory or tumor diseases in the frontal sinus, they often spread into the orbit. Near the zygomatic process of the frontal bone there is a fossa in which the lacrimal gland is located. At the inner edge there is a notch or bony opening - the supraorbital notch, the exit site of the supraorbital artery and nerve. Near the supraorbital notch there is a small depression - a block fossa, near which a block spine is located, to which the tendon block of the superior oblique muscle is attached, after which the muscle sharply changes the direction of its movement. The upper wall of the orbit is bordered by the anterior cranial fossa.
The inner wall of the orbit, for the most part, is formed by a thin structure - the ethmoid bone. Between the anterior and posterior lacrimal ridges of the ethmoid bone there is a depression - the lacrimal fossa, in which the lacrimal sac is located. At the bottom, this fossa passes into the nasolacrimal canal.
The inner wall of the orbit is the most fragile wall of the orbit, which is damaged even with blunt trauma, due to which, almost always, air enters the tissue of the eyelid or the orbit itself - the so-called emphysema develops. It is manifested by an increase in tissue volume, and when palpating, the softness of the tissues is determined with the appearance of a characteristic crunch - the movement of air under the fingers. With inflammatory processes in the ethmoid sinus area, they can quite easily spread into the cavity of the orbit with a pronounced inflammatory process, while if a limited abscess is formed, it is called an abscess, and a widespread purulent process is called phlegmon. Inflammation in the eye socket can spread towards the brain, which means it can be life-threatening.
The lower wall is formed mainly by the upper jaw. The infraorbital groove begins from the posterior edge of the lower wall, continuing further into the infraorbital canal. The lower wall of the orbit is the upper wall of the maxillary sinus. Fractures of the lower wall quite often occur with injuries, accompanied by drooping of the eyeball and infringement of the lower oblique muscle with limited mobility of the eye upward and outward. With inflammation or tumors located in the sinus of the upper jaw, they also pass easily enough into the orbit.
The walls of the orbit have many openings through which blood vessels and nerves pass, which ensure the functioning of the organ of vision. Anterior and posterior lattice openings are located between the upper and inner walls, through which the nerves of the same name pass - the branches of the nasal ciliary nerve, arteries and veins.
The lower orbital fissure is located deep in the orbit, closed by a connective tissue septum, which is a barrier that prevents the spread of inflammatory processes from the orbit into the pterygopalatine fossa and vice versa. Through this fissure, the orbit leaves the lower optic vein, which then connects with the pterygoid venous plexus and the deep facial vein, and the inferior orbital artery and nerve, the zygomatic nerve and the orbital branches extending from the pterygopalatine nerve enter the orbit.
The superior orbital fissure is also tightened with a thin connective tissue film, passing through which three branches of the optic nerve enter the orbit - the lacrimal nerve, the nasal ciliary nerve and the frontal nerve, as well as the trochlear, oculomotor and abducens nerves, and the superior ocular vein leaves. The slit connects the orbit with the middle cranial fossa. In case of damage in the area of the upper orbital fissure, most often injuries or tumors, a characteristic complex of changes occurs, namely, complete immobility of the eyeball, ptosis, mydriasis, small exophthalmos, partial decrease in the sensitivity of the skin of the upper half of the face, which occurs when the nerves passing through the crevice are damaged, as well as enlargement of the veins of the eye due to impaired venous outflow along the superior ophthalmic vein.
The optic canal is a bony canal that connects the cavity of the orbit with the middle cranial fossa. Through it, the ophthalmic artery passes into the orbit and the optic nerve exits. The second branch of the trigeminal nerve passes through the round opening - the maxillary nerve, from which the infraorbital nerve is separated in the pterygopalatine fossa, and the zygomatic nerve in the inferior temporal one. A round hole connects the middle cranial fossa with the pterygopalatine fossa.
Next to the round is an oval foramen connecting the middle cranial fossa with the infratemporal fossa. The third branch of the trigeminal nerve, the mandibular nerve, passes through it, but it does not take part in the innervation of the structures of the organ of vision.
Methods for diagnosing diseases of the orbit
- External examination with an assessment of the position of the eyeballs in the orbit, their symmetry, mobility and displacement with light pressure with fingers.
- Feeling of the outer bony walls of the orbit.
- Exophthalmometry to clarify the degree of displacement of the eyeball.
- Ultrasound diagnostics - identification of changes in the soft tissues of the orbit in the immediate vicinity of the eyeball.
- Radiography, computed tomography, magnetic resonance imaging are methods that determine the violation of the integrity of the bone walls of the orbit, foreign bodies in the orbit, inflammatory changes and tumors.
Symptoms for diseases of the orbit
Displacement of the eyeball relative to its normal location in the orbit: exophthalmos, enophthalmos, upward and downward displacement - occurs in trauma, inflammatory diseases, tumors, changes in the blood vessels in the orbit, as well as endocrine ophthalmopathy.
Impaired mobility of the eyeball in certain directions is observed under the same conditions as previous violations. Swelling of the eyelids, redness of the eyelid skin, exophthalmos is observed in inflammatory diseases of the orbit.
Reduced vision, up to blindness - is possible with inflammatory, oncological diseases of the orbit, trauma and endocrine ophthalmopathy, occurs when the optic nerve is damaged.
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