eye disorders
Angle Closure Glaucoma
Treatment of Angle Closure Glaucoma
Acute:Timolol,pilocarpine, andbrimonidinedrops, oralacetazolamide, and a systemic osmotic agent, followed by laser peripheral iridotomy Similar to primary open-angle glaucoma except that laser peripheral iridotomy should be done if the ophthalmologist feels that the procedure may slow mechanical closing of the angle. Cataract removal helps delay the progression of chronic angle-closure glaucoma. Pupillary dilation should be avoided in people at risk, something important when considering applying topical agents to dilate the eye for examination (eg,cyclopentolate,phenylephrine) or for treatment (eg, homatropine) or when giving systemic medications that have the potential to dilate the pupils (eg,scopolamine, alpha-adrenergic agonists commonly used to treat urinary incontinence, medications with anticholinergic effects). Treatment must be initiated immediately because vision can be lost quickly and permanently. The patient should receive several medications at once. A suggested regimen istimolol0.5% one drop every 30 minutes for 2 doses,pilocarpine2 to 4% one drop every 15 minutes for 2 doses,brimonidine(0.15 or 0.2%) one drop every 15 minutes for 2 doses,acetazolamide500 mg orally initially (IV if patients are nauseated) followed by 250 mg every 6 hours, and an osmotic agent, such as oral glycerol 1 mL/kg diluted with an equal amount of cold water,mannitol1.0 to 1.5 mg/kg IV, or isosorbide 100 g orally (220 mL of a 45% solution). (NOTE: This form of isosorbide is notisosorbide dinitrate.) Response is evaluated by measuring intraocular pressure (IOP). Miotics (eg,pilocarpine) are generally not effective when IOP is>40 or 50 mm Hg because of an anoxic pupillary sphincter. Definitive treatment is with laser peripheral iridotomy (LPI), which opens another pathway for fluid to pass from the posterior to the anterior chamber, breaking the pupillary block. It is done as soon as the cornea is clear and inflammation has subsided. In some cases the cornea clears within hours of lowering the IOP; in other cases, it can take 1 to 2 days. Because the chance of having an acute attack in the other eye is 80%, LPI is done on both eyes. The risk of complications with LPI is extremely low compared with its benefits. Glare, which can be bothersome, may occur. Patients with chronic, subacute, or intermittent angle-closure glaucoma should also have LPI. Additionally, patients with a narrow angle, even in the absence of symptoms, should undergo prompt LPI to prevent angle-closure glaucoma. If a cataract is present, Cataract extraction and lens implant procedures can dramatically delay the progression of chronic angle-closure glaucoma. The medications and full-thickness incisional surgical treatments used for angle-closure glaucoma are the same as those used for open-angle glaucoma. However, laser trabeculoplasty is relatively contraindicated if the angle is so narrow that additional peripheral anterior synechiae may form after the laser procedure. Typically, partial-thickness procedures are not indicated. 