What type of glaucoma is acetazolamide (Diamox) indicated for?

From the Guidelines

Acetazolamide is primarily indicated for acute angle-closure glaucoma as an emergency treatment to rapidly lower intraocular pressure. The medication can also be used as an adjunctive therapy in refractory open-angle glaucoma when other medications have failed to adequately control intraocular pressure 1. The typical dosage for acute angle-closure glaucoma is 500 mg intravenously or orally, followed by 250 mg every 4 hours until pressure is controlled. For chronic management, doses typically range from 250-1000 mg daily, often divided into multiple doses. Acetazolamide works by inhibiting carbonic anhydrase, which reduces aqueous humor production in the eye, thereby lowering intraocular pressure. This mechanism makes it particularly valuable in emergency situations where rapid pressure reduction is needed. Patients should be monitored for side effects including paresthesias, fatigue, metabolic acidosis, and electrolyte imbalances. The medication should be used cautiously in patients with sulfa allergies, kidney disease, liver disease, or electrolyte abnormalities. It's worth noting that the most recent and highest quality study, 1, provides guidance on the clinical findings characteristic of primary open-angle glaucoma, but does not specifically address the use of acetazolamide in this context. However, based on the available evidence, acetazolamide is a valuable treatment option for acute angle-closure glaucoma and refractory open-angle glaucoma. Some key points to consider when using acetazolamide include:

• Monitoring for side effects and adjusting the dose as needed
• Using the medication cautiously in patients with certain medical conditions
• Being aware of the potential for interactions with other medications
• Considering alternative treatment options if acetazolamide is not effective or is not well-tolerated. In terms of specific patient populations, acetazolamide may be particularly useful in patients with acute angle-closure glaucoma who require rapid reduction of intraocular pressure. Additionally, patients with refractory open-angle glaucoma may benefit from the use of acetazolamide as an adjunctive therapy. Overall, acetazolamide is a valuable treatment option for certain types of glaucoma, and its use should be guided by the most recent and highest quality evidence.

From the FDA Drug Label

Long-term administration of acetazolamide is contraindicated in patients with chronic non-congestive angle-closure glaucoma since it may permit organic closure of the angle to occur while the worsening glaucoma is masked by lowered intraocular pressure. In the eye, this inhibitory action of acetazolamide decreases the secretion of aqueous humor and results in a drop in intraocular pressure, a reaction considered desirable in cases of glaucoma and even in certain non-glaucomatous conditions.

Acetazolamide (Diamox) is indicated for the treatment of glaucoma, but the specific type is not directly stated as an indication. However, it is contraindicated in chronic non-congestive angle-closure glaucoma.

• The drug may be used in other types of glaucoma, but this is not explicitly stated.
• The main effect of the drug is to decrease intraocular pressure, which is desirable in glaucoma treatment 2, 2.

From the Research

Indications for Acetazolamide in Glaucoma

• Acetazolamide (Diamox) is indicated for the treatment of acute closed-angle glaucoma, as shown in a study from 1979 3.
• The medication is used to reduce intraocular pressure in patients with this condition.
• However, it is also noted that acetazolamide can cause acute angle-closure glaucoma as a rare but severe adverse effect, as reported in cases from 2011 4, 2016 5, and 2021 6.
• A review of drug-induced acute angle closure glaucoma from 2007 7 also mentions acetazolamide as a sulfa-based drug that can cause this condition by ciliary body edema with anterior rotation of the iris-lens diaphragm.

Important Considerations

• The use of acetazolamide in glaucoma treatment should be carefully considered due to its potential to cause acute angle-closure glaucoma.
• Patients taking acetazolamide should be monitored closely for signs of this condition, and alternative treatments should be considered if necessary.
• In cases where acetazolamide is suspected to have caused acute angle-closure glaucoma, the medication should be discontinued, and treatment with topical corticosteroids, hypotensive, and cycloplegic eye drops may be necessary, as seen in the case reports 4, 5, and 6.