iridocorneal endothelial syndrome
Introduction
Introduction to iris corneal endothelial syndrome Iris corneal endothelial syndrome (iridocorneal endothelialsyndrome, ICE syndrome) more than one eye, more common in 20 to 50 years old, more women than men, manifested as abnormal corneal endothelium, progressive iris matrix atrophy, extensive peripheral pre-irisal adhesion, angle closure And a group of diseases of secondary glaucoma. basic knowledge The proportion of illness: 0.007%-0.008% Susceptible people: more common in women aged 20 to 50 Mode of infection: non-infectious Complications: bullous keratopathy
Cause
Iris corneal endothelial syndrome etiology
(1) Causes of the disease
The exact cause of iris corneal endothelial syndrome has not yet been elucidated. Patients with ICE syndrome lack a positive family history, young or middle-aged disease, and adequate development of histological Dick's membrane, suggesting that this syndrome is an acquired disease. The following reasons include: iris matrix inflammation, vascular abnormalities and ischemia, corneal endothelial proliferative degeneration, progressive corneal endothelial tumor disease, abnormal neural crest cell differentiation, etc., after lymphocytes found in the endothelial cell layer of ICE syndrome patients The hypothesis of chronic inflammation and viral etiology has been proposed, but lymphocytes have also been found in the endothelial cell layer of the posterior corneal polymorphism or hereditary corneal disease.
(two) pathogenesis
Because there are few family history and obvious changes in corneal histology, but also appear after birth, it is considered to be acquired eye disease instead of hereditary or congenital eye disease. According to the current research of clinical and histopathology, there are the following Kind of theory:
1.Campbell Membrane Theory: Rochat and Mulder observed that the iris root adhered to the peripheral part of the cornea, the pupil was displaced to the adhesion side, and the opposite iris side was stretched and thinned, and at the same time there was a single layer of endothelial cells. The composition of the glass membrane, covering the iris corneal angle and iris in the lesion area, based on the clinical observation of 82 cases of primary iris atrophy and the histological study of 10 cases of eyeball removal specimens, proposed the membrane theory, pointing out the basic lesions An abnormality of the corneal endothelium, characterized by corneal edema, and a membrane consisting of a single layer of endothelial cells and a post-elastic layer of tissue, extending across the open iris corneal angle, extending toward the iris, covering the anterior surface of the iris, as the membrane shrinks, Leading to the anterior adhesion of the iris, the trabecular mesh is covered by the membrane, the angle of the anterior chamber is closed, the pupil is deformed and the quadrant is displaced to the peripheral iris, and the iris corresponding to the quadrant is pulled and thinned, and the iris is formed into a sharp hole. At the same time, secondary glaucoma occurs.
2. Ischemia theory: Insufficient blood supply to the iris may be the pathogenesis of primary progressive iris atrophy. Some people think that the iris is hardened and ischemic. It is also suggested that the local inflammatory toxin causes iris ischemia, and some people think that the iris is enlarged. Segmental ischemia of the muscle causes atrophy of the large muscle in a quadrant, and the pupil is displaced toward its corresponding quadrant. Finally, the anterior adhesion and membrane formation around the iris leads to glaucoma.
3. Neural crest cells theory: The mesenchymal tissue of the neural crest cell line differentiates into the corneal endothelium and parenchyma. Under the corneal endoscopic microscope, the early ICE syndrome endothelial cells are significantly reduced, similar to that in infants. Therefore, it is speculated that due to the abnormal proliferation of the original neural crest cells, various types of ICE syndrome are caused.
4. Viral infection theory: Since the presence of lymphocytes is observed in the corneal endothelial cell layer, it is speculated that it may be chronic inflammation caused by the virus, although serological examination of patients with ICE syndrome does not confirm Epstein-Barr virus infection, but for ICE patients The corneal specimens were detected by PCR and found to have herpes simplex virus DNA in the corneal endothelial cell layer, but not in the specimens of normal human cornea and other chronic keratopathy patients.
In addition to the above theory, there is also the theory of inflammation and the theory of primary iris deficiency, that is, the disease is caused by low-grade inflammation in the eye, but in most clinical cases, not only there is no active inflammatory reaction, and histological examination does not support Inflammation; the primary iris defect theory is thought to be related to iris defects such as local dystrophies and open muscle loss.
In today's many doctrines, Campbell's membrane theory is most valued.
Prevention
Iris corneal endothelial syndrome prevention
Corneal edema is mainly used for hypertonic saline and high-tech eye ointment and other eye drops. Patients with high intraocular pressure should be treated with sputum, and if necessary, acetazolamide and mannitol can be used to reduce intraocular pressure. The disease may be related to herpes virus infection, eye health should be maintained, infection should be prevented! Antibiotics and hormonal eye drops should be used after surgery, and gentamicin and dexamethasone can be injected under the conjunctiva if necessary. . For corneal transplantation, cyclosporin A can be taken orally or instilled.
Complication
Iris corneal endothelial syndrome complications Complications , bullous keratopathy
Large vesicular keratopathy, anterior adhesion around the iris and iris atrophy.
Symptom
Iris corneal endothelial syndrome symptoms Common symptoms Pupil deformation Eye pain fog yellow nodules increased intraocular pressure of the cornea size... Dehydrated rainbow
1. General performance: ICE syndrome is basically monocular involvement, common in middle-aged people, and mostly female, male to female ratio is 1:2 ~ 1:5, no genetic predisposition, rare family history, no systemic comorbidities or merger Other eye diseases, although mostly white, are also reported in China. Primary progressive iris atrophy, Chandler syndrome and Cogan-Reese syndrome, although three different diseases, actually represent different variations of a disease. Because the degree of severity of the lesions is different, and different types are shown, the Chandler syndrome is more common in the three, and the degenerative changes of the corneal endothelial cells are common. The difference between the three is mainly the iris change.
ICE syndrome has a chronic, progressive course. It takes more than 10 years from the early stage to the advanced stage. Early vision may appear blurred and intermittent rainbow vision. It is more common in the morning, and most of them start with corneal abnormalities and iris atrophy. Later, due to corneal edema. The anterior adhesion of the iris is increased and the intraocular pressure is increased. Therefore, the visual acuity is affected to varying degrees in different stages of the disease, from mild haze to significant decrease, to the late stage of the disease due to corneal edema and glaucomatous optic nerve damage. There is severe visual impairment, and the vision is worse when getting up in the morning, because the corneal edema is aggravated after nighttime closed-eye sleep, and the cornea can be dehydrated after exposure to the air during the daytime, often accompanied by eye pain, headache and other secondary. Symptoms of glaucoma were found in early ophthalmologic examinations by chance. The first sign of the individual was mostly iris abnormalities, which were characterized by pupillary deformation, polyposis or dark spot-like small nodular nodules in the iris.
2. Common manifestations of type III: changes in the typical ICE syndrome with cornea, iris corneal angle, and iris abnormalities.
(1) corneal lesions: corneal endothelial changes are the main features of ICE syndrome, Chandler syndrome is more common, mostly accompanied by corneal edema, and the severity of glaucoma is lower than the other two types, slit lamp examination see central cornea There are fine silver-like changes in the posterior part, similar to Fuchs corneal dystrophy, but the particles are finer. Under high-magnification microscopic corneal endoscopic or spectroscopic microscopy, characteristic changes of corneal endothelial cells can be seen. Endothelial cells Diffuse abnormalities, which are expressed in cells of different sizes, shapes, densities, and dark areas in the cells. The cells lose a clear hexagonal appearance, so these cells are called "ICE cells", and these cells can be slowly dispersed and covered. Full cornea.
(2) iris corneal angle lesions: a wide range of peripheral anterior adhesion of the iris is another feature of ICE syndrome. The peripheral anterior adhesion can reach or exceed the Schwalbe line, and the anterior adhesion of the small cone-shaped periphery can be gradually intensified from the beginning to a wide base. Or anterior adhesion of the bridge, eventually reaching the entire angle of the anterior chamber, causing an increase in intraocular pressure. About half of patients with ICE syndrome develop glaucoma, which occurs in progressive iris atrophy and Cogan-Reese syndrome, which is more severe than Chandler syndrome. Although the occurrence of glaucoma is related to the degree of anterior angle closure of the anterior adhesion, there are also reports of cases in which the entire anterior chamber angle is open. The histopathological study of the iris corneal angle reveals a single layer of endothelial cells and a similar post-elastic layer. The membrane covers the open corner area and the corner area where the front part of the perimeter has been formed.
(3) iris lesions: different manifestations of three types of ICE syndrome, based on the abnormal state of iris, progressive iris atrophy with significant iris atrophy and different degrees of pupillary shift and ovarian valgus, after The most prominent contralateral quadrant is present in the peripheral anterior adhesion. The progressive atrophy of the iris is characterized by the iris hole formed by the expansion and dissolution of the iris, because the stretching of the hole deforms the pupil in the opposite direction, and the iris of the stretching zone changes. Thin can form holes.
Fluorescein angiography studies indicate that if the dissolved pores are not accompanied by pupillary deformation or iris thinning, resulting from peripheral pre-irisal adhesion caused by non-membrane formation, it is associated with combined iris ischemia.
3. Different manifestations of type III: Iris lesions are the basic point for distinguishing three types of ICE syndrome, but type 3 has the following characteristics.
(1) Primary progressive iris atrophy: the iris angle of the iris is normal at the early stage of the disease, and the intraocular pressure is normal. After the middle part of the iris, the iris matrix is plaque-like atrophy, and gradually the pigment epithelial layer is formed, eventually forming an iris hole and a pupil to the iris. The anterior adhesion direction of the periphery is displaced and deformed; at the same time, the traction of the anterior adhesion of the iris is often combined with the dysplasia of the pigment epithelial layer in the pupil region. When the iris matrix is atrophied and thinned, it is difficult to find the iris blood vessel under the slit lamp examination. Clinically, Two forms of iris hiatus can be seen:
1 Tractional hole: Due to the shrinkage of the membrane, the stretched iris is thinned, the matrix is atrophied and torn, and the pigment epithelium dissolves to form a slit.
2 Solubility: There is no obvious pigmentation valgus or iris thinning at the hole. Fluorescence iris angiography confirms that the hole is caused by ischemia. Clinically, the dissolved hole is rarer than the traction hole (Fig. 1).
(2) Chandler syndrome: corneal edema secondary to corneal endothelial dystrophy, with slight iris atrophy, pupillary shift, some cases still can not detect iris changes, a certain degree of iris matrix atrophy and pupillary shift Position, but no iris cavity caused by iris atrophy, because the iris pigment epithelial layer maintains relative integrity, iris pigmentation layer does not show valgus or only mild valgus, intraocular pressure can be normal or only moderately elevated, long-term Follow-up observation, the pre-adhesion of the surrounding area does not progress, the progress of the disease is very slow, because corneal edema can cause difficulty in iris keratoscopy, even misdiagnosed as primary open angle glaucoma.
Clinically, there is also a variant between primary iris atrophy and Chandler syndrome. The iris lesion is more obvious, but no iris is formed.
(3) Cogan-Reese syndrome: Although the iris can be atrophied to varying degrees, the disease is characterized by diffuse pigmented nodules and sputum on the surface of the iris, due to diffuse corneal endothelial cell hyperplasia, involving the angle of the anterior chamber. The iris forms a peripheral anterior adhesion, resulting in secondary angle-closure glaucoma. The pupil is displaced to the peripheral anterior adhesion, which may be accompanied by a pupillary dysplasia of the pupillary margin, but the iris is rarely seen. The slit lamp is examined: the initial iris surface is sparsely sparse. Light yellow nodules, later converted to dark brown, the iris matrix surrounding the nodules is very flat, but lost its normal iris structure, some cases of ICE syndrome appear nodules on the surface of the iris many years after the disease, there are two iris lesions Types: one is the nodule of the iris surface, such as a small island-like bulge, composed of high-density pigmented parenchymal tissue, the periphery of the nodule is covered on the iris surface and the endothelial layer across the iris cornea angle and a similar post-elastic layer structure The basement membrane-like tissue is wrapped; the other type is characterized by a vortex-like vortex on the iris surface, and the iris crypt disappears. The above two types of iris lesions appear on the same eye. rare.
Examine
Examination of iris corneal endothelial syndrome
1. Corneal endoscopic surface microscopy: to understand the number and morphology of endothelial cells, and can be differentiated from other corneal endothelium diseases.
2. Corner mirror examination: It can be found that there is a pre-adhesion morphology in the periphery, and the structure in the corner is unclear.
3. Ultrastructure: ultrastructural study of the posterior corneal specimens of patients with ICE syndrome. It was found that some abnormal cells covered the collagen tissue behind the normal elastic membrane, including the non-belt layer in the posterior elastic membrane, and the posterior elastic membrane. Layer, abnormally dense collagen and loose collagen and other four layers of collagen structure, the ultrastructure of the cell layer is reported to be quite different and complex, and may be related to the corneal endothelial cell response of this disease, some cells exhibit metabolic activity and differentiation characteristics, some Cells have migratory cell properties (filamentous pseudopods and intracytoplasmic actin filaments), others are disruptive or necrotic, and the controversy surrounding cell properties is whether the cell layer belongs to endothelial cells or upper cells, and recent research supports There are two kinds of cellular components: normal endothelial cells and ICE cells (epithelial cells), and fibroblast-like cells and chronic inflammatory cells (lymphocytes) are still found. In the cell density, some specimens are found as multi-layer cells, but most of them For monolayer cells, the density is significantly reduced or even the cell exfoliation is exposed to the underlying elastic membrane collagen tissue, the iris corneal angle The study of weaving found a cell membrane consisting of a sparse monolayer of abnormal cells and a posterior elastic membrane. This membrane is continuous with the endothelial cells of the posterior cornea and the collagen layer of the posterior elastic membrane. It extends downward from the peripheral cornea and covers the periphery of the iris cornea. In the anterior adhesion area or trabecular meshwork with open angles, a similar cell membrane on the surface of the iris, most often located in the pupillary ectopic and uveal valgus regions, originates from the extension of the iris corneal keratinocyte membrane and forms nodules around the iris stromal tissue.
Diagnosis
Diagnosis and differentiation of iris corneal endothelial syndrome
According to the appearance of unilateral progressive typical iris destruction, the unique anterior adhesion of the iris corneal angle, secondary glaucoma and corneal failure, the disease is not difficult to diagnose, corneal endoscopic surface microscopy is helpful for early diagnosis and differential diagnosis.
Differential diagnosis
Some corneal and iris diseases with glaucoma may be confused with different types of ICE syndrome and should be identified.
Corneal endothelium disease
(1) Fuchsendothelial-epithelial dystrophy: a primary malnutrition of the corneal endothelium, similar to ICE syndrome, but no iridocorneal angle and iris changes, which can be distinguished from ICE syndrome. And its corneal stroma edema is secondary, it is a double-eye disease, has a family hereditary tendency, more common in women, more than 40 years old, slit lamp examination see the corneal surface of the posterior corneal appearance, easy to ICE syndrome Confused, histopathological examination showed thickening of the posterior corneal elastic layer, and the neoplasms protruded to the rear. Due to corneal edema, the stromal layer was immersed in the liquid, and the lysis was plate-like, sometimes liquid and cell debris could be The front elastic layer is separated from the parenchyma layer, and the epithelial layer is edema to form a large bubble, and 10% to 15% of the cases are combined with glaucoma.
(2) posterior polymorphous dystrophy (PPMD): iris and iris corneal angle involvement is very similar to ICE syndrome, is an autosomal dominant two-eye disease, has a family genetic predisposition, more common in childhood The course of the disease is extremely slow and progressive, mainly for corneal lesions. The slit lamp examination shows that the opaque body of the polymorphic map is gathered at the post-corneal elastic layer, and the posterior elastic layer is thickened, such as thick band-like sputum, resulting in Endothelial decompensation causes corneal edema, a few have anterior adhesion around the iris, causing pupillary deformation, pupillary pigmentation eversion and secondary glaucoma, so similar to Chandler syndrome, but Chandler syndrome is often monocular, no family history Compared with the disease, the disease progresses relatively quickly, and there are also obvious differences between the two slit lamp examinations. Histopathological examination: the angle of the anterior chamber can be covered by the corneal endothelium, but the ectopic endothelial cell morphology and Chandler synthesis Different signs have epithelial cell characteristics.
2. Iris-dissolved disease
(1) Axenfeld-Rieger syndrome: a disease of mesoderm dysplasia, manifested as hypoplasia of the iris of the eyes, with a wide peripheral anterior adhesion of the iris, pupillary ectopic, pigmented valgus, iris atrophy and tear formation Occasionally, iris nodules, combined with angle-closure glaucoma accounted for 50%, congenital, family history, usually in late childhood and early adulthood, can be combined with complete or partial edentulous malformation, maxillary hypoplasia, etc. Systemic manifestations, in addition to significant Schwalbe wire loop forward, the disease should be identified with Cogan-Reese syndrome, the latter is monocular, common in middle-aged women, and characterized by iris pigmented nodules.
(2) Aniridia: The incidence of both eyes is autosomal dominant inheritance, with a family history, often combined with other congenital abnormalities of the eye, such as small eyeball, small cornea, lens defect, small optic disc, choroidal defect and lens. There are congenital small opaque bodies, but also congenital anomalies, such as mental retardation, limb and external ear malformations, multi-finger (toe) deformity, etc., slit lamp examination see residual iris root tissue, iris keratoscopy occasionally The root tissue of the iris remaining in the cord, or the abnormal mesodermal tissue, covering the trabecular or remaining on the root tissue of the iris, the iris-free need to be differentiated from the rare progressive iris atrophy with most of the iris deficiency .
(3) Iridoschisis: The incidence of both eyes, seen in the elderly, manifested as spontaneous ipsilateral stromal layer division and release, but no iris holes, occasional corneal edema and secondary angle-closure glaucoma.
(4) ectopia lentis et pupillae: ectodermal dysplasia, involving both eyes, autosomal recessive inheritance, more family history of blood marriage, eye manifestations of small lens, lens and pupil Displacement and deformation, pupils are not easy to loosen and sphincter atrophy, there may be monocular double vision, lens dislocation is the cause of secondary glaucoma.
3. Iris nodules and diffuse pigmented lesions
(1) Neurofibromatosis (Von Recklinghausen): is a neuroectodermal dysplasia, mostly monocular, or both eyes of the autosomal dominant genetic disease, due to neuronal, Schwann cells, nerve fibers and pigment cell proliferation, resulting in Pigment membrane thickening, eye tissue can be widely affected, such as eyelids, eyelids, uvea, retina, cornea, palpebral conjunctiva and bulbar conjunctiva, slit lamp examination see pigmented nodules on the iris surface, its morphology is different from Cogan-Reese syndrome It is flat and has no stem, accompanied by iris heterochromia and iris neovascularization. If the iris cornea or iris root is invaded, it can form a peripheral anterior adhesion, causing secondary glaucoma.
(2) diffuse iris malignant pigmentoma: clinically, the iris syndrome is misdiagnosed as malignant melanoma, and the eyeball is removed, so the identification of the two is quite important. The disease is characterized by thicker iris and darker color. There are few pupillary deformations, peripheral adhesions and glaucoma, and free tumor cells can be detected in the aqueous humor, which may be associated with mild iritis.
(3) Sarcoidic uveitis: sarcoidosis is a benign chronic systemic disease of unknown etiology. 10% to 50% of patients have eye involvement, and the iris and pupillary margins can be scattered in grayish white or yellowish gray nodules. Most of the anterior uveal inflammatory manifestations (male fat KP, aqueous humor flash), often combined with retinal, choroidal and vitreous lesions, due to inflammation of the trabecular meshwork, obstruction by exudate or formation of peripheral anterior adhesions, can cause secondary Sexual glaucoma.
