exfoliation syndrome
Introduction
Introduction to exfoliation syndrome Exfoliationsyndrome (pseudoexfoliation) is an abnormal protein synthesized by various ocular tissues, which blocks the trabecular meshwork and causes trabecular dysfunction, and elevated intraocular pressure leads to glaucoma. basic knowledge The proportion of illness: 0.001% Susceptible people: no specific people Mode of infection: non-infectious Complications: cataract Glaucoma
Cause
Cause of exfoliation syndrome
(1) Causes of the disease
1. Although there is a report on the pathogenesis of familial XFS, the genetic pattern is still unclear. The results of the relationship between XFS and chronic open angle glaucoma in the same lineage are different.
2. Infections Some people found that the incidence of XFS in 343 couples was significantly higher than when they lived alone. Ringvold found that there were 30-50 nm membrane-bound microparticles in XFS eye specimens, suggesting that there may be a virus causing the disease. In this regard, further research is needed. the study.
3. The climate has suggested that the disease is related to sun exposure. The XFS of Australian residents is closely related to ultraviolet light. XFS appears to be more common in Pakistani mountain populations than in low-altitude populations.
(two) pathogenesis
1. Pathogenesis The source of exfoliation has the following two theories: The theory of sedimentation is that the exfoliation is derived from the epithelial cells under the anterior capsule of the lens, which then deposits on the surface of the lens, but after the removal of the cataract capsule, the exfoliation It still exists, indicating that the lens is not dominant in the formation of exfoliation. It is also suggested that the exfoliate is from the iris, because the iris's anterior membrane, the pigment epithelial layer and the blood vessel wall have exfoliates. The local production theory is that the exfoliation is derived. The degeneration of the lens capsule or the abnormal metabolism of the lens epithelial cells occurs. As the age progresses, the exfoliation of the lens epithelial layer gradually moves to the surface through the capsule, and some people hold the viewpoint of simultaneous exfoliation and sedimentation.
2. The pathogenesis of XFS combined with glaucoma In general, only a small number of patients with XFS may be associated with glaucoma, most of which are not accompanied by glaucoma after many years of follow-up observation. XFS combined glaucoma is often open-angled, with normal anterior chamber depth, possible The mechanism is that the combination of exfoliation and pigment blocks the trabecular meshwork. In addition, the trabecular cells are impaired due to the production and accumulation of exfoliating substances, but the latter is not the main reason, because sometimes it can be used on the trabeculae of normal eyes. A wide range of pigmentation has emerged. It has been confirmed that there are exfoliation in the trabecular meshwork, destruction of the Schlemm tube, presence of pigment molecules in the trabecular meshwork, and pathogenesis of XFS combined with angle-closure glaucoma: XFS combined with angle-closure glaucoma is generally very Rare or just coincidence, most reported as sporadic cases, the prevalence rate is 1.5% to 3%, but the narrow angle of the angle in XFS is more common, Wishart et al in 76 cases of XFS gonioscopic examination, in 73 cases of glaucoma 32% of the angles of the anterior or posterior occipital cerebral palsy were increased. In all cases, the trabecular pigmentation increased. When the pigment was obviously asymmetrical, the occurrence of glaucoma was more common. The anterior chamber volume of XFS was more contrast. Reduced, presumably a cause or result of the disease.
Prevention
Exfoliation syndrome prevention
Prevention: There is currently no relevant content description.
The occurrence of exfoliation syndrome is global, but it is characterized by regional distribution. The prevalence of exfoliation syndrome has recently been reported to be higher than before. In Norway, England, Iceland, Sweden, Denmark, and Germany, there is a racial difference in the incidence of exfoliation syndrome in high-incidence areas, but it varies from country to country. More common in whites, and Chinese are rare. The prevalence in the United States is similar to that in Western Europe. The Eskimo prevalence rate is almost zero, Indians can be as high as 38%, Iceland's highest prevalence is about 25%, Finland is more than 20%, and Denmark is about 5% lower. Exfoliation syndrome has a tendency to increase with age and the onset age is often 69 to 75 years old, rarely less than 40 years old. There are also reports that the minimum age is 22 years old. Gender differences are reported differently. Some people think that male patients with common exfoliation syndrome are most likely to have glaucoma. Other studies have found no gender differences in patients with exfoliation syndrome with glaucoma.
The prevalence of exfoliation syndrome with glaucoma is also different (0% to 93%). Most of the open-angle glaucoma has about 20% angle-closure glaucoma. The prevalence of exfoliation syndrome in open-angle glaucoma is much higher than in age-matched non-glaucoma populations in central Norway, with 60% of glaucoma patients being affected. 26% of Danish open-angle glaucoma is associated with exfoliation syndrome, compared with 8.1% for Australians and 34% for India.
Complication
Exfoliation syndrome complications Complications cataract glaucoma
Nuclear cataract and glaucomatous optic nerve damage.
Symptom
Symptoms of exfoliation syndrome Common symptoms Ciliary congestion, nystagmus, habit, chin, dislocation, pigmentation, elevated intraocular pressure, high skin peeling
1. General clinical manifestations The course of XFS is very slow, up to 10 to 20 years. There are many very minor and important changes in the anterior segment of the eye, which need to be carefully examined under the slit lamp to identify:
(1) Conjunctiva: Under normal circumstances, there is no obvious abnormality in the conjunctiva. In progressive cases, fluorescein angiography can show regular marginal vascular defects and neovascular areas, which can be characterized by anterior ciliary vascular congestion.
(2) cornea: there are diffuse clusters or flaky fine debris-like exfoliation behind the endothelial layer, occasionally Krukenberg fusiform deposition, and some corneal endothelium changes lightly, including decreased cell count, morphological changes, This damage can occur in both eyes, regardless of the severity and duration of the accompanying glaucoma.
(3) Iris and pupil: There are coarse granular pigmentation areas on the anterior surface of the iris, few iris tremors, abnormal iris angiography, including reduced number of blood vessels, loss of normal radial shape, neovascular plexus and fluorescence leakage, and iris sphincter There is a special pigmentation, and the peripheral part of the iris is rare. The sphincter in the vicinity of the pupillary area is examined by iris transillumination and is characterized by irregular "moth-like" or "vortex"-like pigmentation plaques. Below, the pupillary margin presents a diagnostic gray-white debris piece, most of which can be seen without expansion, which is an easily overlooked sign in early XFS patients.
(4) Anterior chamber and anterior chamber: When there is no expansion, occasionally a small amount of pigment floating in the anterior chamber is seen. After the expansion, the pigmented rafts are obviously increased, while the depth of the anterior chamber is no different from that of the normal eye. The trabecular meshwork of the iris cornea angle Pigmentation, uneven distribution, sometimes a pigment line called Sampaolesis line above the Schwalbe line, but this line is not as obvious as the pigment dissemination syndrome, there may be a small amount of dispersed state of debris in the corner, in the anterior chamber The pigmented float is caused by the iris rubbing off the surface of the crystal to cause it to fall off. This is also a characteristic manifestation of XFS. The trabecular mesh pigment tends to be jagged, spotted, and unclear. These are early diagnoses. Characteristics, trabecular mesh pigmentation and eye pressure increase are closely related, with XFS in patients with normal tension glaucoma, this pigmentation is rare.
(5) Lens: After the expansion, the surface of the crystal is divided into 3 zones: the translucent central zone; the granular peripheral zone and the middle transparent zone. The central zone has a diameter of 1 to 2.5 mm, and the boundary is clear. There are exfoliation debris, 18% to 20% of patients have no central panel, and the exfoliation of the edge is often rolled forward. The transparent area in the middle is caused by the physiological activity of the pupil being rubbed by the iris on the surface of the lens. The surrounding area always exists. It may be granular in its periphery, while the center is foggy white and radial stripes. The latter is often seen, and the surrounding granular layer is the undestroyed exfoliation. In the treatment of decompression, the central panel may Developed into a granular form, connected to the middle zone of the central zone and the surrounding zone, occasionally bridge-like exfoliation.
The early appearance of exfoliation on the lens can be a uniform frosted glass or grass-like appearance, or a fuzzy radial non-granular-like striped ring distributed in the middle third of the posterior anterior capsule of the iris. These signs use narrow bands. Focusing on the surface of the lens at an angle of 45° is easy to find. Over time, the stripe widens and fuses to form a continuous tooth line. Scheimbflug photography helps early detection of XFS, and exfoliation can also occur on the intraocular lens. .
(6) Ciliary body and suspensory ligament: using a cytoscopic (cycloscope) examination, there may be exfoliation accumulation in the latitudinal zone, suspensory ligament and ciliary process in the lens. The suspensory ligament is often severely affected and can be completely covered by the exfoliate. Or instead, due to increased fragility, rupture, incomplete dislocation or complete dislocation of the lens, in the XFS cataract extraction, due to suspensory ligament lesions, postoperative complications are greatly increased.
(7) Vitreous body: There is exfoliation accumulation on the front vitreous membrane, and exfoliation is also found on the vitreous fiber. It has been reported that the exfoliation on the vitreous body continues to increase several years after the removal of the intracapsular capsule, further illustrating the exfoliation. It also comes from other tissues than the lens capsule.
2. Clinical manifestations of glaucoma with XFS can increase the intraocular pressure by 30mmHg after dilation, so I should pay attention to intraocular pressure measurement after dilation in XFS patients. XFS can be combined with open angle and angle closure glaucoma. The former is more common. And the damage to the optic nerve is often heavier than the primary open angle glaucoma, that is, the visual field damage and optic disc damage are obvious, but the response to drug treatment is poor, XFS may be accompanied by corneal edema and acute intraocular pressure, often high At 50mmHg, the angle of the anterior chamber is open. The angle-closure glaucoma occurs because the weakness of the suspensory ligament causes the lens to move slightly forward, which makes it easy to lock the pupil. Especially in the supine position, the squat is aggravated, and the pilocarpine can promote XFS. The formation of closed angle glaucoma.
3.XFS and eye related diseases and systemic relationship
(1) Cataract: The relationship between XFS and cataract formation is getting closer and closer, but the etiology of the two is still unclear. The cataract in XFS is significantly increased, and vice versa. In XFS, the capsule is ruptured and vitreous is prolapsed. It is a common complication of extracapsular cataract extraction, and elevated intraocular pressure often occurs. There may be "adhesion" between the lens cortex and the capsule. The average thickness of the lens capsule of XFS is not significantly different from that of normal people.
(2) Ischemia: XFS iris is widely involved, the lumen of the blood vessels is narrowed, the perfusion is reduced, and even the lumen can be completely occluded. The vascular endothelial cells and pericytes are degenerated. It is found that 50% of patients with XFS have flushing and limbs. There are also abnormalities in the blood vessels, and the extension of the neovascular branch to the posterior iris may result in a decrease in microvolemia. In one study, enucleation was performed for neovascular glaucoma caused by central retinal vein occlusion (CRVO), with 35% associated Exfoliating glaucoma.
(3) keratoma: Sometimes in XFS male patients, the cornea has elliptical degeneration (climate foamy keratopathy), while female patients do not. There are also such lesions in Australian residents, this relationship may be caused by environmental factors.
(4) Relationship with the whole body: XFS is now considered to be a systemic disease. Exfoliation can occur in various tissues of the eye and connective tissue or fibrous septum of heart, liver, lung, etc., and its relationship with systemic diseases is not In Qinghai, patients with XFS with glaucoma have reduced AH secretion and increased HB secretion compared with primary chronic open angle glaucoma. It has also been found that 34.4% of XFS preoperative aqueous humor has antinuclear antibodies in diabetic retinopathy. Especially in those patients with proliferative retinopathy, the incidence of XFS is low. In patients with TLA, XFS has a higher incidence than age-matched normal people, suggesting that in XFS, hypoperfusion may have a certain Role.
Examine
Exfoliation syndrome
1 Conjunctiva and cornea: Under the electron microscope, the conjunctiva at the limbus and the endothelial cells near the basement membrane of the conjunctival vasculature have typical microfibrous granules, and the detached exfoliated material can be seen in the corneal endothelial cells.
2 trabecular meshwork: trabecular mesh gap and Schlemm tube, there is exfoliation, ultrastructure shows that exfoliate accumulates in trabecular meshwork endothelial cells and inside and outside of Schlemm tube, even in vacuoles in endothelial cells .
3 Iris: There is exfoliation adhesion in the margin of the pupil, and the exfoliated material is scattered on the matrix of the iris, the crypt, the anterior membrane, the muscle fibers between the sphincter and the open muscle, the posterior surface of the iris and the surrounding blood vessels, and the exfoliation by electron microscopy. Located under endothelial cells with rupture of the basement membrane and degeneration.
4 lens and suspensory ligament: typical lens changes can be divided into three areas: A. Central area: see microfibrous exfoliation under scattered electron microscopy, scattered cell organs and pigment particles, under optical microscope and electron microscope, see There is only a very loose attachment between the lens capsule and the exfoliated material, so it is easy to be erased by external mechanical contact; B. Intermediate area: light microscopy and electron microscopy, no exfoliation exists in this area, the lens capsule in this area The membrane is also normal; C. Peripheral particle area: under the light microscope and electron microscope, there are fine dendritic exfoliation on the surface of the anterior capsule of the lens in this area, sometimes containing pigment, occasionally the post-iris adhesion caused by the presence of exfoliation, in addition, before Exfoliates are visible in both the latitudinal zone and the suspensory ligament of the posterior lens.
5 Ciliary body: The ciliary process is covered with exfoliation such as down, and the exfoliate adheres firmly to the ciliary epithelial cells.
No special auxiliary inspection.
Diagnosis
Diagnostic identification of exfoliation syndrome
Diagnostic criteria
According to the characteristic performance of the slit lamp inspection, there are some gray or white flaky exfoliate debris and some or all of the pigmentation folds of the pupil edge. After the expansion, see the three areas of the surface anterior capsule surface sedimentation. There are pigments released in the anterior chamber and posterior corneal endothelium. Special pigmentation on the iris sphincter is rare in the peripheral part of the iris. Corneroscopy (use of Koeppe mirror is more suitable than Zeiss or Goldmann angle mirror) ): trabecular pigmentation increases, the distribution is uneven, the outline is unclear or spotted, which can be used as a feature of early diagnosis. The pigmentation forms a Sampadesis line in front of the Schwalbe line, the iris angiography changes abnormally, and the vascular shape of the conjunctiva is missing. It is helpful for diagnosis, intraocular pressure, visual field and fundus examination to determine the presence or absence of co-existing glaucoma. Examination of the exfoliation of the lens with Scheimbflug photographic technique is helpful for early XFS findings.
Differential diagnosis
1. Pigment dissemination syndrome is most easily confused with exfoliation syndrome, and is also one of the most important diseases in the differential diagnosis of XFS. Pigment dissemination syndrome is a spontaneous disease, mainly manifested in myopia patients aged 30 to 40 years old, in males. Patients are more likely to be associated with glaucoma, but women are rare. The ratio of the two is 2:1 to 3:1. The pigment particles released from the iris are small and do not diffuse on the iris surface, but accumulate in the iris folds, often with Krukenberg. Fusiform pigmentation, transillumination examination has a fissure in the middle of the iris, and the radial pigment is missing. The pigment band on the trabecular mesh is often denser than XFS. It is difficult to identify in the elderly, and the pigment band is smoother. In the posterior band of the trabecular meshwork, the pigment band of the XFS is clearly gravel.
Some patients with pigment dissemination syndrome can develop XFS, bilateral glaucoma is also prone to occur, because the pigment dissemination syndrome is almost bilateral symmetry, one with bilateral pigmentation syndrome and high monocular pressure Older patients should be suspected of having XFS.
2. Iris inflammation secondary glaucoma iritis is positive for aqueous humor, with cell floatation, accompanied by pre-irisal adhesion or posterior adhesion of the iris, patients are generally younger, and can be combined with systemic diseases, such as young sexual rheumatoid joints Inflammation, while there is no exfoliation in the front of the eye.
3. Other types of lens exfoliation
(1) true lens exfoliation (capsular delamination): the disease is seen in ocular trauma, severe uveitis and exposure to high temperature operations, etc. Slit lamp inspection shows that the anterior capsule of the crystal has a transparent sheet with curled edges. It is different from the exfoliation of this disease, and is often accompanied by glaucoma.
Foreign bodies such as copper, iron eye trauma can also occur in the lens exfoliation, but very rare, irrigated trabecular mesh pigmentation, but no exfoliation on the anterior lens capsule can be identified, there are other causes of trabecular mesh pigmentation For example, Fuchs heterochromic iridocyclitis, senile or postoperative atrial role factors, pigments caused by intraocular tumors, combined with their other clinical manifestations, identification is not difficult.
(2) Primary familial amyloidosis: a systemic disease with some ocular manifestations, may be associated with glaucoma, at the iris and pupillary margin, the anterior capsule of the crystal has grayish flaky exfoliation and at the corner of the iris cornea Pigmentation, unlike the XFS in ultrastructure, may be a subtype of XFS.
