Closed-angle glaucoma

Anti-cholinergics Tiotropium bromide remains bound to M3-receptors for up to 36 h, and requires only daily intake, whereas other anti-cholinergics (e.g. ipratropium, oxytropium) have to be given up to four-times daily and are often used as maintenance treatment. Possible side-effects are dry mouth, metallic taste after inhalation and very rarely close-angle glaucoma. 

The nurse notifies the primary health care provider immediately if eye pain increases or if it has not begun to decrease 3 to 4 hours after the first dose. If the patient has acute closed-angle glaucoma, the nurse checks the pupil of the affected eye every 2 hours for dilation and response to light. 

There are two major types of glaucoma open-angle glaucoma, which accounts for most cases and is therefore the focus of this chapter, and closed-angle glaucoma. 

Closed-angle glaucoma occurs when there is a physical blockage of the trabecular meshwork, resulting in increased IOP. 

Closed-angle glaucoma Topical anticholinergics Topical sympathomimetics Systemic anticholinergics Heterocyclic antidepressants Low-potency phenothiazines Antihistamines Ipratropium... 

In closed-angle glaucoma, patients typically experience intermittent prodromal symptoms (e.g., blurred or hazy vision with halos around lights and occasionally, headache). Acute episodes produce symptoms associated with a cloudy, edematous cornea ocular pain nausea, vomiting, and abdominal pain and diaphoresis. 

For closed-angle glaucoma, the presence of a narrow angle is usually visualized by gonioscopy. IOP is generally markedly elevated (e.g., 40 to 90 mm Hg) when symptoms are present. Additional signs include hyperemic conjunctiva, cloudy cornea, shallow anterior chamber, and occasionally edematous and hyperemic optic disk. 

Acute closed-angle glaucoma with high IOP requires rapid reduction of IOP. Iridectomy is the definitive treatment, which produces a hole in the... 

Epinephrine should be used with caution because it can precipitate acute closed-angle glaucoma, especially when used with a /1-blocker. 

Phenothiazines tend to have antimuscarinic properties and are therefore contraindicated for use in patients with closed-angle glaucoma. Antimuscarinics are contraindicated in closed-angle glaucoma as they may worsen the condition. 

Secondary glaucoma and preoperative treatment of acute congestive (closed-angle) glaucoma -... 

Contraindications Closed-angle glaucoma, severe anemia, head injury, postural hypotension, hypersensitivity to nitrates... 

Contraindications Closed-angle glaucoma, GI hypermotility or malabsorption (extended-release tablets), head trauma, hypersensitivity to nitrates, increased intracranial pressure, orthostatic hypotension, severe anemia (extended-release tablets)... 

Contraindications Allergy to adhesives (transdermal), closed-angle glaucoma, constrictive pericarditis (IV), early MI (sublingual), GI hypermotility or malabsorption (extended-release), head trauma, hypotension (IV), inadequate cerebral circulation (IV), increased intracranial pressure (ICP), nitrates, orthostatic hypotension, pericardial tamponade (IV), severe anemia, uncorrected hypovolemia (IV)... 

Contraindications Phenylephrine HCl injection should not be used with patients with severe hypertension, ventricular tachycardia or fibrillation, acute myocardial infarction (Ml), atrial flutter or fibrillation, cardiac arrhythmias, cardiac disease, cardiomyopathy, closed-angle glaucoma, coronary artery disease, patients who have a known hypersensitivity to phenylephrine, sulfites, or to any one of its components. 

Used as drops long (5-6 days) action Toxicity Increased intraocular pressure in closed-angle glaucoma Interactions With other antimuscarinics... 

Primary angle closure glaucoma (also known as acute close-angle or narrow-angle glaucoma) results from blockage of aqueous humour flow into the anterior chamber. The condition develops very quickly with a sudden increase in eye pressure. The eyes become very painful and red. 

Tolterodine can only affect the narrow-angle glaucoma (primary closed-angle glaucoma) and is contraindicated in uncontrolled cases of this type of glaucoma. It is therefore necessary to establish if the deterioration in the patient s vision is due to tolterodine use. In order to prevent optical nerve damage, an earlier appointment with the consultant is possibly warranted and therefore the patient should be advised to contact the consultant for further advice. 

Closed angle glaucoma. Since drainage of aqueous humor is impeded during relaxation of the pupillary sphincter, intraocular pressure rises. 

The doctor made a diagnosis of an acute attack of closed-angle glaucoma, as a result of his narrow drainage angles and the probable exposure to a mydriatic agent. 

Q4 Yes. Rob has used both atropine and phenylephrine this afternoon. Muscarinic antagonists such as atropine, tropicamide and cyclopentolate cause dilation of the pupils. The a-adrenoceptor agonists, such as phenylephrine, also produce my driasis. Mydriasis may cause acute closed-angle glaucoma in some patients. It is unlikely that a very small amount of cocaine in the eye would cause problems, but in cocaine overdose pupils become widely dilated. This is due to blockade of uptake 1, a process normally involved in terminating the effects of noradrenaline. In the presence of cocaine the effects of sympathetic stimulation on the eye would be prolonged and the pupil would dilate. Morphine causes constriction of the pupils via opiate receptors. 

Patients with closed-angle glaucoma have a small angle between the iris and cornea which can also completely close and therefore flow of aqueous humour will be prevented. This results in a rise in IOP, which must be reduced quickly to prevent any damage to the retina. 

Q10 Beta-adrenoceptor antagonists are contraindicated in patients with asthma or respiratory obstructive diseases, bradycardia, heart block or heart failure. Adrenergic agonists are contraindicated in patients with closed-angle glaucoma and should be used cautiously in patients with hypertension or heart disease. Parasympathomimetics cause poor night vision and dimming of vision, because of development of miosis, headache and brow ache. Carbonic anhydrase inhibitors have a weak diuretic action and can induce depression, drowsiness, paraesthesia, electrolyte disturbance such as hypokalaemia, acidosis and lack of appetite. 

Mydriasis (dilation of the pupil) can be caused by muscarinic antagonists and a-adrenoceptor agonists. Mydriasis may cause acute closed-angle glaucoma in some patients. 

An 84-year-old woman developed acute closed-angle glaucoma after taking paroxetine for 6 days (SEDA-21, 13). 

A 70-year-old woman taking paroxetine developed acute closed-angle glaucoma (4). 

Various neuroleptic drugs, particularly low-dose phe-nothiazines and thioxanthenes, commonly cause blurred vision secondary to their anticholinergic activity. This is primarily a nuisance, except in the rare patient with closed-angle glaucoma. 

---