Angle-Closure Glaucoma

(Closed-angle glaucoma)

An angle-closure glaucoma is a glaucoma associated with a chronic or rare acute physical angle closure. Symptoms of an acute anterior chamber angle closure are severe eye pain and redness, reduced visual acuity, colored halos around lights, headache, nausea and vomiting. Intraocular pressure (IOP) is increased. To prevent permanent visual loss, in acute cases immediate initiation of treatment with local and systemic medication is required. This is followed by the definitive treatment, an iridotomy on.

In the US, about 10% of all glaucoma are angle closure glaucoma.

An angle-closure glaucoma is a glaucoma associated with a chronic or rare acute physical angle closure. Symptoms of an acute anterior chamber angle closure are severe eye pain and redness, reduced visual acuity, colored halos around lights, headache, nausea and vomiting. Intraocular pressure (IOP) is increased. To prevent permanent visual loss, in acute cases immediate initiation of treatment with local and systemic medication is required. This is followed by the definitive treatment, an iridotomy on. In the US, about 10% of all glaucoma are angle closure glaucoma. Etiology At an angle-closure glaucoma, the iris either the anterior chamber angle pulled (the junction of the iris and cornea in the periphery of the anterior chamber) or get displaced so that the aqueous humor drainage is physically blocked and the IOP increases (see table: narrow-angle glaucoma: classification based on mechanisms the outflow obstruction *). An increased IOP damages the optic nerve to. Angle-closure glaucoma: classification based on mechanisms of outflow obstruction * Type diseases Examples Anterior (pull mechanism) contraction of membranes Iridokorneales endothelial syndrome neovascular glaucoma Posterior polymorphous dystrophy surgery (. Eg corneal transplant) trauma (penetrating and nichtpenetrierend) – contraction inflammatory deposits – – Inflammatory membrane Fuchs Heterochromieiridozyklitis Interstitial keratitis by syphilis – Posterior (printing mechanism) with lens-induced pupillary mechanisms Intumescent lens subluxation of the lens Mobiles lenses syndrome Posterior synechiae pupillary in aphakia pseudophakia uveitis pupillary block glaucoma – Without pupillary block glaucoma Malignant (Ziliarblock) – cysts of the iris and ciliary body – Anterior displacement of the glass body by lens extraction – intraocular tumors malignant melanoma retinoblastoma lens-induced mechanisms Intumescent lens subluxation of the lens cell It lenses syndrome plateau iris syndrome – uveal edema after scleral buckling, panretinal photocoagulation or central retinal vein occlusion of the retinal tissue contraction Retrolentikuläre Persistent hyperplastic primary vitreous Retinopathy of prematurity led (retrolental fibroplasia) * There are clinical examples; no comprehensive list of glaucoma. . Adapted from Ritch R, Shields MB Krupin T: The Glaucomas, ed 2. St. Louis, Mosby, 1996, p 720; by permission. Pathophysiology An angle closure may be primary (cause unknown) or secondary (consequence of another disease; see table: open-angle glaucoma: classification based on mechanisms of outflow obstruction *) and be acute, subacute chronic occur (intermittent) or. Primary angle-closure glaucoma Small chamber angles are not to be found usually in young people. With age, the lens continues to grow. Some, but not all people, the iris is pushed through this growth forward and narrows the anterior chamber angle. Risk factors for the development of a narrow chamber angle include family history, advanced age and ethnicity; the risk is higher in people of Asian and Inuit ethnicity and lower in people of European and African descent. With narrow anterior chamber angle, the distance between the iris in the pupil region and the lens is very low. If the iris dilates, the iris is centripetal and pulled back so that it comes reinforced with the lens in contact. This blocks the water passage chamber between the lens and iris passing through the pupil into the anterior chamber (this mechanism is referred to as pupillary). Under the pressure caused by the continuous aqueous humor of the ciliary body in the posterior chamber, the iris periphery is urged forward (which is a forward curved iris caused with the label “iris bombe” [ “iris bombe”]), and closes the chamber angle. This closure blocks the aqueous outflow and leads rapidly (within hours) to strong (> 40 mmHg) increase in IOP. Because of the rapid onset of the condition is referred to as a primary acute angle closure glaucoma. It is an ophthalmic emergency that requires immediate treatment. Nichtpupillare block mechanisms include the plateau iris syndrome, in which the central anterior chamber, although deep, the peripheral anterior chamber but was flattened by an even front shifted ciliary body. The intermittent angle-closure glaucoma is observed when an episodic pupillary spontaneously regresses after a few hours, mostly to sleep in the supine position. The IOP then increases slowly. The chronic angle-closure glaucoma occurs when the chamber angle closes slowly and may form scars between peripheral iris and trabecular meshwork. In any patient with a narrow chamber angle one pupil dilation (mydriasis) can urge the iris into the anterior chamber angle and precipitate acute angle-closure glaucoma. This development is of particular importance in the use of topical agents to the eye for the investigation (eg. As cyclopentolate, phenylephrine) to expand or treatment (eg. As homatropine) or when systemic drugs are administered, which have the potential to dilate the pupils (z. B. scopolamine, ?-adrenergic agonists that are often used to treat urinary incontinence, drugs with anticholinergic effects) .Sekundäres angle-closure glaucoma, the mechanical chamber angle obstruction is (by a concurrent disease such as proliferative diabetic retinopathy caused PDR), ischemic central retinal vein occlusion, uveitis or epithelial ingrowth. By contraction of a neovascular membrane (z. B. at PDR) or inflammatory scarring of the iris can be drawn into the chamber angle. Symptoms and signs Acute Angle-Closure Glaucoma Patients have severely painful, red eyes, reduced visual acuity, colored halos around lights, headache, nausea and vomiting. The systemic symptoms can be so severe that the patients a supposed neurological or gastrointestinal problem can be diagnosed. Typical examination findings are conjunctival hyperemia, turbid cornea, fixed, medium dilated pupil and signs of inflammation in the anterior chamber. Visual acuity is reduced. The IOP measurement is usually 40-80 mmHg. Since corneal edema is, the optic nerve is difficult to see. The field is not examined because of the deterioration of the general condition. For the primary mechanisms of narrow-angle glaucoma (z. B. pupillary block and plateau iris) may make an investigation of the uninvolved other eye View the diagnosis. Tips and risks in patients who have sudden headache, nausea and vomiting, the eyes should be examined. Chronic angle-closure glaucoma This form of glaucoma manifests itself as open-angle glaucoma. Some patients have red eyes, blurred vision, feeling unwell or suffer from headaches. These complaints can (under the action of gravity, perhaps due to the sleep induced miosis and rearward displacement of the lens) during sleep after. On the Gonioscopy the angle is narrow and peripheral anterior synechia (adhesions between the iris and the peripheral angle structure that causes a blocking of the trabecular meshwork and / or the Ziliarkörperoberfläche), also referred to as PAS can be seen. IOP may be normal, but generally increased in the affected eye. Diagnosis Acute: IOP measurement and clinical findings Chronic: Gonioscopy showing peripheral anterior synechiae and characteristic abnormalities of the optic nerve and the visual field, the diagnosis of acute angle closure glaucoma is made clinically and by the IOP measurement. Because of the opacity of the cornea with a corneal epithelium verletzlichem Gonioscopy may be difficult to perform in the affected eye. But the investigation of the other eye reveals a tight or sealed chamber angle. If the other eye has a wide chamber angle, a different diagnosis should be considered as a primary angle-closure glaucoma considered. The diagnosis of chronic angle closure glaucoma due to the presence of peripheral anterior synechiae (PAS) in gonioscopy and characteristic changes in the optic nerve and the visual field (see symptoms and complaints of primary open-angle glaucoma). Treatment Acute: timolol, pilocarpine and brimonidine drops, orals Acetazolamide and a systemic osmotic drug (Editor’s note: This should actually be mandatory and specified or a systemic acetacolamide), which is followed by a peripheral laser iridotomy. Chronic: Similar to the primary open angle glaucoma, except that a peripheral laser iridotomy may be performed when the ophthalmologist considers that the process could slow the mechanical closure of the angle. Acute angle-closure glaucoma, the therapy must be initiated immediately, because the visual acuity can go quickly and permanently lost. The patient should immediately receive different medications. is recommended therapy with timolol 0.5% (2 times 1 drop with 30-minute intervals), pilocarpine 2-4% (1 drop every 15 min), Brimonidine 0.15 or 0.2% (1 drop every 15 min), apraclonidine 0.5 or 1% (2 times 1 drop with 30-minute intervals), acetazolamide (500 mg po at the beginning [iv, if it is ill patients], followed by 250 mg every 6 h) and a osmoticum such as glycerol (1 ml / kg po, dissolved in the same amount of cold water) or mannitol (1.0-1.5 mg / kg iv) or isosorbide 100 g po (220 ml of a 45% solution). (Note: This form of isosorbide is isosorbide dinitrate). The reaction can be evaluated by measurement of the IOP. From an IOP> 40 mmHg or 50 are not effective or miotics (z. B. pilocarpine) in general, since the Pupillensphinkter is ischemic and not responding. The final treatment consists of the peripheral laser iridotomy, which opens the water chamber to another discharge path from the back to the front chamber and dissolve the pupillary. It is performed as soon as the cornea clear and the inflammation has subsided. In some cases, the cornea clears within hours after lowering the IOP, in other cases it may take 1-2 days. Because to get an acute attack the other eye, the probability, is 80%, the peripheral laser iridotomy is performed on both eyes. Compared to the benefits of peripheral laser iridotomy the risk of complications is extremely low. Glare (double vision), which can be annoying, can auftreten.Chronisches angle-closure glaucoma in patients with chronic, sub-acute or intermittent angle-closure glaucoma, a peripheral laser iridotomy should also be performed. In addition, a peripheral iridotomy should be performed at a narrow chamber angle without symptoms immediately to prevent angle-closure glaucoma. The medical and surgical treatment similar to that of open-angle glaucoma. A chamber angle, which is so narrow that could form more anterior synechiae after the laser procedure, represents a relative contraindication for laser trabeculoplasty. Typically, non-penetrating, lamellar surgery not indicated. Summary The angle-closure glaucoma may be acute, intermittent or chronic develop. Acute angle-closure glaucoma should be suspected based on clinical findings and confirmed by an IOP measurement. A chronic angle-closure glaucoma should be confirmed by peripheral anterior synechiae and changes in the optic nerve and visual field. The acute angle-closure glaucoma should be treated as an emergency. It should be consulted an ophthalmologist, to cause a peripheral laser iridotomy for all patients with angle-closure glaucoma.

Health Life Media Team

Leave a Reply