Akersonfeld-Riegel syndrome
Introduction
Introduction to Aksenfeld-Rigger Syndrome Axenfeld-Riegersyndrome (Axenfeld-Riegersyndrome) refers to a group of developmental diseases with developmental defects of both eyes, with or without systemic abnormalities, characterized by: 1 developmental defects in both eyes; May be associated with systemic developmental abnormalities; 3 secondary glaucoma; 4 autosomal dominant inheritance, more family history, there are reports of sporadic cases; 5 men and women have the same incidence. basic knowledge The proportion of illness: 0.02% Susceptible people: no specific population Mode of infection: non-infectious Complications: cataract Retinal detachment
Cause
The cause of Aksenfeld-Rigger syndrome
(1) Causes of the disease
Axenfeld-Rigger's abnormality or syndrome is autosomal dominant, male and female have equal chances of disease, often have a familial history, but there are also reports of sporadic cases. The origin of the disease is that Axenfeld- Rieger syndrome is a type of disease that develops malformation. Reese believes that the iridocorneal angle is incompletely differentiated and causes abnormal development of the anterior segment of the anterior segment. The keratoconus keratosis syndrome is included, including Axenfeld abnormality, Rieger abnormality, Peter abnormality, etc. 3 In the disease, the anterior chamber is formed and differentiates into the iris corneal horn structure at 4 to 6 months of the embryo. At this time, if the mesoderm tissue between the cornea and the iris is stagnant, and the cells and tissues remain, it will cause abnormalities in the anterior segment of the eye. Recent studies have revealed that neural crest cells are the most likely primary tissues of Aksenfeld-Rigger or syndrome. The development of the anterior segment of the eye from the neural crest cells is blocked at the end of the embryo, leading to the iris and iris cornea. Anomalies in the horny primitive endothelial cells and variations in the aqueous drainage system.
(two) pathogenesis
Based on clinical and histopathological observations and modern understanding of normal anterior segment development, there is a theory that some anterior ocular structures originating from neural crest cells stop developing in the third trimester, causing eye syndrome in patients with AR syndrome. Damage, including abnormalities in the original endothelial cell layer of the iris and iris cornea, and variations in the aqueous drainage structure.
1. Iris changes in front of the iris, the tissue strip of the iris cornea and the abnormal Schwalbe line, there is an abnormal membrane tissue, representing the residual island of the original endothelial cell layer, the membrane contraction on the iris surface may be ectopic with the pupil Membrane valgus, iris atrophy is related to the formation of holes. Of course, atrophy and hole formation may also be related to other factors such as ischemia. Residual primitive endothelial cells are associated with iris and corneal adhesion. During normal embryo development, this primitive The endothelial cell layer should disappear, but the patients with AR syndrome remain, and extend from the edge of the corneal endothelium to the periphery of the iris, and some pigment tissues are in contact with the membrane to form an iris corneal tissue band.
2. The abnormal development of the primitive endothelial cell layer in the corneal horn of the posterior corneal nucleus causes the junction of the corneal endothelium and the trabecular endothelial layer to shift forward. Due to the metabolic abnormality of the endothelial cell layer, the posterior elastic membrane of the peripheral part is abnormal or The elastic membrane-like structure covers the trabecular meshwork, and a large number of cells with abnormal activity occur at this junction, and the Schwalbe line is thickened and advanced.
3. Abnormal drainage of aqueous humor The developmental stagnation at the end of the third trimester of pregnancy blocked the anterior pigmentary tissue from retreating completely, causing the iris to adhere to the posterior part of the trabecular meshwork at a high level; developmental stagnation may also lead to trabecular meshwork and The Schlemm tube is incompletely formed, both of which can cause the drainage of the aqueous humor to be affected and the intraocular pressure to rise.
4. Other forebrain, pituitary gland, maxillary bone and most of the cartilage and teeth originate from neural crest cells, so abnormal development of the neural crest can also explain the abnormal development of the pituitary, facial bone and teeth, in addition to the iris matrix, The choroidal, pigmentary cells of the skin and hair are all developed from the melanocytes of the neural crest, but the abnormal development of the neural crest cells does not explain all the clinical manifestations of the intrinsic, such as excessive skin wrinkles around the umbilical cord and abnormalities of the genitourinary system. The AR syndrome also involves primitive outer embryonic layers other than neural crest.
Prevention
Aksenfeld-Rigger Syndrome Prevention
Light trabeculoplasty or iridotomy is not effective. Surgery with an incision should be selected including a sacral incision, trabeculectomy, and trabeculectomy. Due to the incomplete development of Schlemm's and trabecular meshwork, most patients have a low success rate with the first two procedures. Most commonly used in Aksenfeld-Rigger syndrome with glaucoma for the addition of antimetabolites for trabeculectomy. As for other types of glaucoma, ciliary body condensation or ciliary body photocoagulation through the sclera may be used when drugs and filtration surgery are not effective, and some improvements may be obtained.
Complication
Axenfeld-Rigger syndrome complications Complications cataract retinal detachment
Axenfeld-Rigger syndrome can present non-characteristic eye changes such as strabismus, limbal cutaneous tumor, cataract, retinal detachment, macular degeneration, chorioretinal defect, choroidal dysplasia and optic disc Dysplasia and so on.
Symptom
Axenfeld-Riegel Syndrome Symptoms Common symptoms Pupils deformed corneal post-embryo pupil abnormal large cornea
1. The typical change of the cornea is the post-corneal embryonic ring, that is, the Schwalbe line proliferates and advances. From the front of the cornea or the slit lamp microscope, there is a white line or ring behind the cornea near the limbus, which is confined to a certain part ( The most common side of the temporal side is 360°, and the post-corneal embryonic ring is 8% to 15% in the general population. There are also a few patients with no post-corneal embryonic ring but other ocular and systemic abnormalities of this syndrome. Outside the corneal changes, other parts are transparent, occasionally large cornea or small cornea, a small number of patients can see congenital opacity in the central part of the cornea, such as patients with long-term glaucoma, older, especially those who have done internal eye surgery, The number, morphology and size of corneal endothelial cells may vary from mild to moderate.
2. Iris corneal angle With iris keratoscopy, a typical prominent Schwalbe line is visible. A strip is attached to the periphery of the iris from the periphery of the iris. The color and texture of the strip are similar to the iris tissue, and the thickness is different. Some are fractured, one end attached to the other end of the cornea attached to the iris, each quadrant may have 1 or 2 or several tissue strips, and some of the entire circumferential trabecular meshwork is covered by tissue strips, such tissue strips There is no direct relationship between the number of belts and the obstruction of aqueous exudation channels. There is no conclusion that the anterior cerebral ventricle can be seen at a slightly distant corner of the tissue strip, but the iris is terminated due to the high attachment of the surrounding iris. At the back of Xiaoliang.com.
3. In addition to the abnormality of the surrounding iris, some irises in the AR syndrome are normal (Axenfeld abnormality in the traditional classification). In other cases, the iris defect is thinned from mild matrix to obvious iris atrophy, and pore formation , pupillary ectopic, pigmented valgus (which is a Rieger anomaly in the traditional classification), etc. When there is a pupil ectopic, the pupil can be displaced to a distinct peripheral tissue strip under the slit lamp microscope, and the iris atrophy and pore formation In the quadrant away from the ectopic direction of the pupil, the iris ectopic change will gradually develop in a few patients, including ectopic or deformation of the pupil, thinning of the iris or formation of the hole, and thickening of the surrounding iris tissue.
4. About 35% of patients with AR syndrome develop glaucoma in glaucoma, which can be shown in infancy, but more in children or young people, mostly in patients with iris band, but the number of tissue bands is positive with glaucoma. The ratio has not been confirmed.
Examine
Examination of the Aksenfeld-Rigger syndrome
1. Genetic testing determines the genetic pattern.
2. Pathological examination
(1) iris corneal angle: The typical change of the iris cornea angle is that the thick line-like strip tissue crosses the corner of the iris from the periphery of the iris and adheres to the prominent Schwalbe line, and the tissue strip is as thin as a line (Fig. 1). Some are as thick as a curtain or a wide band, and some seem to be broken. One end is attached to the cornea, and the other end is attached to the iris. Its color and texture are similar to those of the iris tissue. Some patients have multiple tissue strips in one quadrant. There are only 1 or 2 strips, and some of the trabecular meshes of the corners are covered by tissue strips. The number of tissue strips is directly related to the obstruction of the outflow channel.
The angle outside the iris tissue strip is open, but the iris is attached to the high position, attached to the posterior part of the trabecular meshwork, and the sclera is covered by the surrounding iris. This change involves a quadrant to the entire iris cornea, showing the iris. Another dysplasia of the corneal angle.
(2) Iris: defects of the iris structure are common in this disease, mainly manifested as dysplasia of the iris matrix, thinning of the iris matrix, loss of normal texture, variability of the pigment epithelial layer, atrophy, formation of iris fissure caused by matrix defects, pupil displacement Deformation, multiple pupil or pupillary membrane closure, etc. Occasionally, residual sphincter fibers surround the pupil like a ring, and the displacement of the pupil usually shifts toward the convex tissue strip, and iris atrophy and tear formation often occur. Away from the quadrant of the pupil eccentricity, iris fluorescein angiography can be seen as thinning and bending of the blood vessels around the pupil, accompanied by leakage and segmental delayed filling.
In a few patients, the abnormal changes of the iris will gradually develop, and the changes include ectopic or deformation of the pupil, thinning of the iris or formation of the hole, and thickening of the surrounding iris tissue.
(3) The cornea: a thickened protrusion and a forward-moving Schwalbe line are visible in the peripheral part of the cornea, consisting of a modified colloidal matrix composed of a tissue similar to the iris matrix, with a corneal or iris corneal corner. An abnormal membrane, which is most common on the iris in the direction of pupil deformation. The peripheral iris is attached to the posterior portion of the trabecular meshwork. The outer layer of the trabecular meshwork is usually compressed. In some cases, the Schlemm tube is degraded or absent.
Scanning and transmission electron microscopy of the trabeculectomy specimens revealed that the trabecular meshwork was compressed from the inner surface to the outer surface, the slab layer was compressed, the trabecular meshwork was dense, significantly narrowed or without trabecular space, and even the trabecular space was completely filled with endothelial cells. The lamellar layer is composed of a connective tissue core formed by collagen fibers, surrounded by a thick basement material, and the ciliary body and the peripheral iris matrix are attached to the posterior portion of the trabecular meshwork. The compressed trabecular mesh layer, in some specimens, shows that the basement material covers this connection.
In some specimens lacking a Schlemm tube, a small gap lining one or more endothelial cells can be seen, and an amorphous material separates the gap from the adjacent trabecular meshwork.
Diagnosis
Diagnosis and diagnosis of Axenfeld-Rigger syndrome
Diagnostic points
Diagnosis based on the clinical features of the disease is not difficult, mainly based on the following:
1 The presence of the posterior corneal embryonic ring: a typical feature of this disease, which is characterized by thickening and advancement of the Schwalbe line, but the intrinsic manifestation is not manifested in every patient, and individual patients may not have this post-corneal embryonic ring. However, with other typical manifestations of the eye and the whole body, it is worth noting that this post-corneal embryonic ring can also occur in normal eyes, with an incidence of 8% to 15%, which is manifested by the isolated Schwalbe line protruding forward without There are other eye changes. In addition, the posterior corneal embryo ring is occasionally seen in patients with primary congenital glaucoma and iris corneal endothelial syndrome.
2 iris corneal angle abnormality: its main feature is that the thick tissue band from the surrounding iris across the angle crypt, connected with the prominent Schwalbe line, and the angle of the corner is open, but the iris root is attached to the high position, the sclera tendon is often Cover, the root of the iris is attached to the back of the trabecular meshwork.
3 iris abnormalities: mainly manifested as thinning of the iris, loss of normal texture, dying of pigment epithelial layer, deformation of pupil, multi-pupil and pupillary membrane closure, etc.
4 may be associated with systemic abnormalities: mainly dental and facial developmental defects; such as tooth defects, small teeth, no teeth; flat middle face, maxillary dysplasia, in addition to other systemic abnormalities,
5 secondary glaucoma: more than 50% of patients have secondary glaucoma, more common in childhood and adolescents, but also in infants or middle-aged,
6 eyes on the onset: the vast majority of the incidence of both eyes, very few single eye disease,
7 no gender differences,
8 The disease has a family history.
According to the above characteristics, the disease can be diagnosed, but it should be noted that not every variation is fully manifested in one person, even if there are several members in one family who are sick, each patient's eye and body abnormalities Performance can vary, so you should be aware of other diseases before making a diagnosis.
Differential diagnosis
1. Iridocorneal endothelial syndrome (ICE) In ICE syndrome, abnormalities of iris and iris cornea angle are very similar to AR syndrome in clinical and histopathology, which makes some scholars think that the two kinds of synthesis Signs are part of a series of common abnormalities, but clinical manifestations can be distinguished as ICE including corneal endothelial abnormalities, monocular disease, no family history, adolescent onset, histopathology, and the two syndromes are characterized by a membrane On the anterior and iris surfaces, many different lesions can form when the membrane contracts, but the membrane of the AR syndrome represents a remnant of the original endothelial cell layer, while the ICE syndrome is due to abnormal corneal endothelial proliferation.
2. Posterior corneal polymorphic dystrophy (PPD) PPD is similar to Aksenfeld-Rigger syndrome. It is congenital, both eyes are onset, autosomal dominant, and symptoms appear in adulthood. It can be expressed as iris atrophy and iridocorneal angle abnormality, but the difference of PPD is abnormality of corneal endothelium layer and posterior elastic layer. Under the slit lamp microscope, there is a vesicular or saclike appearance behind the cornea, which is arranged in a line or cluster. Surrounded by a gray, fuzzy halo, the corneal stroma and epithelial edema are partially visible.
3. Peter anomaly This disease is a series of abnormalities, including the central cornea, iris and lens, which are similar to the Aksenfeld-Rigger syndrome and have been included in the same dysplasia. In the classification, the developmental abnormalities of the two diseases are different.
4. Aniridia In this dysplasia, residual iris and anterior chamber abnormalities with glaucoma may confuse some patients with the Aksenfeld-Rigger syndrome.
5. Congenital iris dysplasia (congenital irishypoplasia) is only iris dysplasia, no axenfeld-Rigger syndrome corner or any other abnormalities, but can be associated with adolescent glaucoma and autosomal dominant inheritance By.
6. Ocular dysplasia (oculodentodigitaldysplasia) In this disease, the dysplasia of the teeth is the same as the Aksenfeld-Rigger syndrome. Even mild iris dysplasia, corneal defects, small eyeballs and glaucoma are seen.
7. The lens and ectopic ectopia (ectopia lentis etpupillae) are autosomal recessive diseases, binocular lens and pupil ectopic, both of which are typically displaced in the contralateral direction, pupillary ectopic and Axonfe Deer-Rigger syndrome is similar, but the developmental defects of the iris-free corneal angle are different.
