Ocular neurofibromatosis

Introduction to ocular neurofibromatosis Neurofibromatosis (NF-1) is also one of the vertebral hamartomas. Clinically, it is characterized by skin pigment abnormal spots and trunk, multiple limbs and peripheral tumor-like multiple tumor-like hyperplasia, also known as multiple neurofibromatosis. basic knowledge Probability ratio: the probability of a pregnancy rate of 1% in pregnant women Susceptible people: no special people Mode of infection: non-infectious Complications: orbital schwannomas meningioma

Cause of ocular neurofibromatosis

(1) Causes of the disease

Neurofibromatosis is mostly an autosomal dominant genetic disease, but there are also cases of recessive inheritance, and the growth and development of neuroectodermal tissue cells.

(two) pathogenesis

At present, the pathogenesis of this disease is not fully understood. Some people think that the onset of neurofibromatosis is related to the abnormal development of neural crest cells during embryonic period. Some people believe that the cause of the disease is mainly because the interaction between cells and the chemical properties of the extracellular environment are affected. As a result, some people believe that the secretion of nerve growth hormone is related to the pathogenesis of this disease.

Regarding the pathogenesis of glaucoma, it is generally believed that the main mechanism of obstruction of aqueous humor outflow is that neurofibroma directly invades the angle of the anterior chamber. A layer of avascular, transparent, dense tissue can be seen extending from the surrounding iris to the corner of the corner. The factors are ciliary body and choroidal neurofibromatosis involving the hypertrophy, forward shifting the angle of the anterior chamber, some cases have anterior chamber dysplasia, residual anterior chamber angle, incomplete ventricular division, Schlemm tube malformation or insufficiency When the angle of the anterior chamber and the iris root are directly invaded by the neurofibroma, the iris can be extensively anteriorly adhered, and the fibrous vascular membrane is formed to cover the angle of the anterior chamber to cause neonatal glaucoma.

Prevention of ocular neurofibromatosis

Pay attention to the usual habits and find early treatment.

Ocular neurofibromatosis complications Complications orbital schwannomas meningiomas

Neurofibromatosis can be associated with orbital schwannomas, meningiomas, optic nerves, and optic gliomas. Regular review of MRI is important for early detection, early diagnosis, and treatment.

Symptoms of ocular neurofibromatosis Common symptomsEversion iris

Most neurofibromatosis is one of the manifestations of neurofibromatosis, and neurofibromatosis has many clinical manifestations, involving the central nervous system, peripheral nervous system, bones, muscles, skin and eyes, and the nerves are often nerve fibers. The predilection site of tumor disease can invade almost all eye structures and tissues, mainly:

1. The eye area is easily affected by the eyelids, eyelids, uvea, optic nerve, cornea, conjunctiva, sclera, lens and vitreous.

(1) Eyelid: The eyelid is the most frequently affected part. The upper eyelid is more common, often unilateral. The plexus neurofibroma of the upper eyelid is diffuse hyperplasia of the subcutaneous tumor cells, soft hypertrophy without borders, such as dough. It can cause mechanical ptosis, which is characterized by a characteristic "S"-like upper eyelid deformity. The lesions continue to proliferate and cause cleft palate, and the upper palate can also have double episodes and double squats. This plexus or local The pedicled fibroids are often accompanied by pigmented spots, affected by the upper and lower temporal skin, increased pigmentation of the ankle and loss of the tibia.

(2) eyelids: nodular or plexiform neurofibroma in the orbit: can cause the eyeball to protrude, the sacral wall, sphenoid dysplasia, often showing the external wall of the iliac crest, the sacral bone is missing, the supracondylar fissure is enlarged, and the range is larger. Bone defects cause meningeal or meningeal brain tissue to break into the sputum, and pulsatile eyeballs appear. Because the carotid artery pulsates and passes through the intracranial conduction, there is no vascular murmur, and there is no tremor in percussion.

(3) iris hamartoma (Lisch nodules): iris hamartoma is common in bilateral, hemispherical white or yellow-brown bulging spots, clear-cut gel-like nodules, called iris nodules, raised in the iris It often grows from the age of 16 and continues to develop with age. In addition, it can also have congenital uveal valgus and the presence of iris.

(4) Choroidal hamartoma: the incidence rate is 30%, which is brown-black flat or slightly elevated, and scattered in the polychromatic area.

(5) Optic nerve: glioma or hamartoma can occur, about 1/4 to 1/2 of patients with optic glioma with neurofibromatosis, can also be true tumor, the tumor is often in the subarachnoid space Proliferation, onset at 4 to 8 years of age, manifested as unilateral ocular unilateral protrusion and loss of vision, optic disc edema or atrophy, 90% of cases will involve the anterior segment of the optic canal and cause optic nerve hole enlargement, B-mode ultrasound or CT examination The optic nerve is enlarged, and the X-ray shows an enlargement of the optic nerve.

(6) Retina: Glial hamartoma can also occur, corneal nerve is thick, conjunctiva, superficial sclera occasionally fibrous hyperplasia or mass, sclera may have pigmentation, sometimes causing eyeball enlargement, bulls eye, but eye The pressure is not high.

(7) neurofibromatosis with glaucoma: congenital glaucoma due to abnormal tissue obstruction in the anterior chamber angle, the diameter of the eyeball is large, when the tumor involves the ipsilateral upper eyelid or the eyeball itself, it should be noted that glaucoma may have been combined. The incidence rate can be as high as 50%. Glaucoma often occurs at birth or shortly after birth. Occasionally, there are occasional late-onset patients. Most of them are open-angled in clinical practice. Most single eyes are present. If glaucoma occurs earlier, congenital glaucoma occurs. The lesions, if they occur later, are similar to open-angle glaucoma in adults.

2. Whole body performance

(1) skin coffee-like pigmentation spots: This is the most common sign of this disease, also known as Cafeau Lait spots, which are multiple, varying in size (several millimeters to several centimeters), irregular brown spots on the edges, more Located in the trunk, on the back, under the armpit, the number is often related to the severity of the disease. As long as one is found, neurofibromatosis should be considered. These skin coffee spots are more than 6 and the diameter is 15mm or a diameter is 6cm. The above has diagnostic significance. This plaque has appeared at birth or shortly after birth. The size and number of this plaque will increase during childhood. The pathological change is caused by the increase of basal cell layer pigmentation caused by the increase of dopa-positive pigment cells.

(2) cutaneous neurofibroma: a diffuse plexiform neuroma formed by the proliferation of peripheral nerve sheath cells, which occurs during puberty, and the number of tumors increases during the lifetime, because the surface of the tumor is thickened and pleated. It feels like a worm bag when palpation, so it is also called neuroma-like elephantiasis, and some of them are fibrosis, which are pigmented and pedicled, soft tumor nodules, connective tissue, proliferating nerve sheath cells and Increased cutaneous nerve composition, these subcutaneous masses are multiple, severe cases can have hundreds, all over the body, vary in size, small as peas, as large as eggs, mostly distributed along the nerve trunk, beaded, most Prominent body surface, some under the skin, skin or subcutaneous neurofibroma is the main diagnostic indication for this disease, according to international diagnostic criteria, the above mentioned type I neurofibromatosis (NF-1), there is a special clinical The type is neurofibromatosis type II, and the internationally differentiated neurofibromatosis types I and II are as follows:

1 neurofibromatosis type I: is an autosomal hereditary disease with an incidence of about 1/3000. Its gene is located on the long arm of chromosome 17, and the diagnostic criteria for type I neurofibromatosis:

Neurofibromatosis type I can be diagnosed if there are two or more of the following symptoms:

A. More than 6 coffee spots, pre-pubertal diameter > 6cm, diameter after puberty > 15cm.

B. Two or more types of neurofibromatosis or one plexiform neurofibromatosis.

C. Freckles in the abdomen or longitudinal axis.

D. Definite bone lesions, such as sphenoid dysplasia or cortical thinning with or without pseudoarthrosis.

E. Optic glioma.

F. More than 2 Lisch nodules (iris hamartoma).

G. Parents, one of the siblings has a neurofibromatosis type I or a child with neurofibromatosis type I.

2 neurofibromatosis type II (NF-2): formerly known as bilateral acoustic neurofibromatosis or central neurofibromatosis, is a rare clinical autosomal malformation, the incidence The rate is about 1/50,000 to 1/40000. The gene is located on the 22nd autosome, and the diagnostic criteria for type II neurofibromatosis:

Have one of the following two:

A. Enhanced MRI or CT scan confirmed bilateral acoustic neuroma.

B. Parents, one of the siblings has a neurofibromatosis type II or a neurofibromatosis type II child, or has a unilateral acoustic neuroma or has one of the following signs: a. neurofibromatosis, b. meningioma , c. glioma, d. schwannomas, e. posterior subcapsular cataract in young patients.

(3) Changes in the skeletal system: About 29% of patients have congenital skeletal defects, which are characterized by hypertrophy and erosion. X-ray and microscopic findings are similar to cystic fibrous osteitis, often involving sphenoid bones and eyelids. The spine and limbs can also be affected.

(4) Changes in the nervous system: At the same time as the central nervous system is involved, there are often intracranial masses, such as meningiomas, gliomas, etc., tumors can cause intracranial hypertension, dizziness, exercise or sensory disturbances, visual field defects, bilateral auditory nerves Tumors are more common, causing symptoms of pons, and spinal cord, cranial nerves, peripheral nerves, sympathetic nerves and adrenal glands (pheochromocytoma) can be involved.

(5) Others: Some patients have atrophy of the semi-lateral part, and a few may have mental retardation, mental disorders, cryptorchidism and the like.

Examination of ocular neurofibromatosis

1. Genetic testing performs some of the necessary genetic tests to determine the type of NFI and NFII mutations.

2. The main features of pathological examination are excessive hyperplasia of the neuroectodermal structure and tumor formation, accompanied by hyperplasia of mesodermal tissue. The typical pathological changes are neurofibromas composed of spindle cells, which vary in size and mainly grow in peripheral nerves. It can also occur in cranial nerves, spinal nerves or horsetails. Neurofibromas are basically composed of sheath cells. Some scholars believe that tumors are the result of diffuse proliferation of surrounding Schwann cells, while others believe that they are derived from the inner and outer membranes.

3. X-ray examination of the diagnosis of neurofibromatosis (NF-1) mainly depends on the absence of bone around the iliac crest, thickening of the soft tissue of the iliac crest and the iliac crest or the soft tissue of the cord, with or without congenital skeletal defects. For bone hypertrophy and erosion, similar to fibrous cystic osteitis, pay special attention to the sphenoid wing and eyelids.

4. B-ultrasound or CT can confirm the optic nerve and retina, X-ray examination of the optic nerve hole.

5. Pay attention to the monitoring of intraocular pressure when glaucoma occurs.

6. CT and MRI examination of NF-1 neurological diseases mainly include visual glioma, non-neoplastic hamartoma, glioma, plexiform neurofibroma, scattered intraspinal neurofibromatosis and dural dilatation, Various structural abnormalities are also often found, such as macrocephaly, which can be diagnosed only by many hamartomas or high-signal lesions in the brain of children on MRI. The typical manifestations of these lesions in T2WI For the focal high signal zone combined with the occupancy effect, these lesions generally do not involve local edema, mainly in the basal ganglia and internal sac area, but also in the midbrain, cerebellum and subcortical white matter, such lesions can not be displayed in non-enhanced CT It is not enhanced on MRI.

Bilateral acoustic neuroma is the most common and typical sign of NF-2, but some patients have only diagnosed with unilateral acoustic neuroma. Patients with NF-2 have meningioma, schwannomas, and spinal ependymoma. The tendency, not optic glioma, astrocytoma or hamartoma, only a small number of patients may have eyelid tumors, so the orthodontic neurogenic tumors should be asked whether there is any other history of surgery, especially the history of acoustic neuroma, Asked if there are symptoms such as hearing impairment.

Diagnosis and diagnosis of ocular neurofibromatosis

According to the typical clinical manifestations of the disease, combined with the auxiliary examination can confirm the diagnosis, the diagnostic criteria of neurofibromatosis are:

1. 6 or more skin pigmentation spots, at least 15 mm in diameter or axillary freckles.

2. Skin and subcutaneous benign neurofibroma are the main markers of this disease.

3. "Central type" is difficult to diagnose in the absence of skin signs, can be based on the presence or absence of positive family history, bilateral acoustic neuroma, unilateral pulsatile ocular protrusion, and mental retardation, seizures, spinal deformities, etc., and carefully Examination can be confirmed when skin signs are obtained.

4. For a small number of difficult cases, a biopsy or a certain stage of the disease is required to confirm the diagnosis.

Neurofibromatosis severity classification:

Grade I: mildest (skin manifestations, pigmented spots, no concurrent neurofibroma).

Grade II: mild (mild spine curvature, precocious puberty, behavioral disorder).

Grade III: Moderate (medical care required, unilateral hypertrophy, controlled onset, gastrointestinal involvement).

Grade IV: major sensory or motor center lesions (intracranial mass, severe mental retardation, severe scoliosis, unable to control seizures).

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