Which drug induced glaucoma? Identifying high-risk medications

October 8, 2025 •

5 min read

Did you know that approximately one-third of acute angle-closure glaucoma cases are triggered by a prescription or over-the-counter medication? Understanding which drug induced glaucoma is crucial for patients and healthcare providers alike, as it can be a serious, vision-threatening side effect.

Quick Summary

Several medications can trigger or worsen glaucoma by increasing intraocular pressure. Key culprits include corticosteroids, anticholinergics, certain antidepressants, and sulfa-based drugs. Mechanisms vary based on the drug and type of glaucoma, requiring vigilance from patients and clinicians.

Key Points

Corticosteroids are the main cause of open-angle drug-induced glaucoma: Steroids, in any form, can increase intraocular pressure over time by clogging the eye's drainage system.
Anticholinergics trigger pupillary block angle-closure glaucoma: Medications like certain antidepressants, cold remedies, and bladder treatments can dilate the pupil and physically block drainage in individuals with narrow angles.
Sulfa-based drugs cause idiosyncratic angle closure: An unpredictable reaction to medications like Topiramate or certain antibiotics can cause the ciliary body to swell, pushing the lens forward and closing the angle.
Know your risk factors: Individuals who are hyperopic, older, have a family history of glaucoma, or have pre-existing narrow angles are at higher risk for drug-induced angle-closure glaucoma.
Prompt action is critical: For acute angle-closure glaucoma, immediate medical attention is necessary to prevent permanent vision loss. Informing your doctor about all medications is key to a fast diagnosis.
The delivery route matters: Topical eye drops, periocular injections, and oral steroids carry a higher risk of raising eye pressure than systemic routes.
Regular monitoring is essential: High-risk patients on long-term systemic or potent topical medications should undergo regular eye pressure checks to catch any changes early.

Understanding the link between medication and glaucoma

Glaucoma is a group of eye conditions that damage the optic nerve, often due to abnormally high intraocular pressure (IOP). While genetics and other diseases are primary causes, a significant number of cases are a secondary effect caused by certain medications. This is known as drug-induced glaucoma and can affect people with or without pre-existing eye conditions. The risk varies depending on the type of medication, dosage, and a person's individual susceptibility.

Two main types of glaucoma exist: open-angle and angle-closure. These types are differentiated by the state of the eye's drainage system, or trabecular meshwork.

Open-angle glaucoma is the more common form, developing slowly over time as the eye's drainage angle remains open but the trabecular meshwork becomes clogged, slowing fluid outflow.
Angle-closure glaucoma occurs when the iris (the colored part of the eye) blocks the drainage angle completely. This can cause a rapid, painful spike in eye pressure and is a medical emergency.

Identifying which drug induced glaucoma depends on understanding these distinctions, as different drugs affect the eye through different mechanisms.

Drugs that induce open-angle glaucoma

Corticosteroids are the most well-known and common medication class that can lead to open-angle glaucoma. Steroid-induced ocular hypertension occurs when corticosteroids cause increased resistance to aqueous fluid outflow in the eye's drainage system. While potent topical eye drops pose the highest risk, any form of steroid administration can lead to elevated IOP, including oral tablets, nasal sprays, inhaled steroids for asthma, and even dermatological creams used on the eyelids.

Types of corticosteroids known to increase IOP

Prednisolone: Often cited as a frequent culprit, especially in eye drop and oral forms.
Dexamethasone and Difluprednate: Highly potent topical steroids that carry a significant risk of elevating IOP.
Triamcinolone: Used in periocular and intravitreal injections, which can cause IOP spikes months after administration.
Fluorometholone: A less potent topical steroid, but still associated with IOP elevation.
Beclomethasone: An inhaled steroid that can raise IOP in susceptible individuals.

The risk of steroid-induced glaucoma is higher in those with pre-existing open-angle glaucoma, a family history of glaucoma, high myopia, or diabetes. The IOP elevation typically resolves a few weeks to months after discontinuing the steroid, though chronic use can lead to permanent damage.

Medications that cause angle-closure glaucoma

Angle-closure glaucoma is a sudden, dramatic event caused by a mechanical blockage of the eye's drainage system. Medications can trigger this by two primary mechanisms: pupillary block and ciliochoroidal effusion.

Pupillary block mechanism

This is the more common mechanism for drug-induced angle closure and involves the pupil becoming dilated (mydriasis), which causes the iris to bunch up and block the drainage pathway. Medications with anticholinergic or adrenergic properties are often responsible.

Anticholinergics: These drugs block the parasympathetic nervous system, causing the pupil to dilate. Examples include:
- Antidepressants (tricyclic antidepressants like amitriptyline, SSRIs like fluoxetine).
- Cold and flu remedies (antihistamines like diphenhydramine, decongestants like pseudoephedrine).
- Urinary incontinence medications (oxybutynin, tolterodine).
- Parkinson's disease medications (trihexyphenidyl).
- Botulinum toxin (Botox), especially injections around the eye.
- Anti-nausea medications (scopolamine, meclizine).
Adrenergic agonists: These stimulate the sympathetic nervous system, also causing pupil dilation. Examples include:
- Ophthalmic dilating drops (phenylephrine).
- Nasal decongestants (pseudoephedrine, ephedrine).
- Respiratory medications (albuterol, salbutamol).

Ciliochoroidal effusion mechanism

This is a less common but crucial idiosyncratic reaction, most often triggered by sulfa-based drugs. It involves the ciliary body and choroid swelling, pushing the lens-iris diaphragm forward and causing angle closure. This is non-pupillary block, meaning dilating the pupil is not the cause, and laser iridotomy (a common treatment for pupillary block) is ineffective.

Sulfa-based drugs: Examples include:
- Topiramate (Topamax): An anticonvulsant and migraine medication with numerous reported cases.
- Acetazolamide (Diamox): A diuretic and glaucoma medication that, paradoxically, can cause angle-closure in this manner.
- Antibiotics containing sulfamethoxazole.
- Methylsulfonylmethane (MSM) supplements.

Comparison of medication-induced glaucoma mechanisms


Feature	Open-Angle (Steroid-Induced)	Angle-Closure (Pupillary Block)	Angle-Closure (Ciliochoroidal Effusion)
Drug Class	Corticosteroids (topical, oral, inhaled, injected)	Anticholinergics, Adrenergic Agonists	Sulfa-based drugs (e.g., topiramate), tetracyclines
Mechanism	Impaired outflow through the trabecular meshwork due to cellular and protein changes	Iris dilation blocks the drainage angle	Ciliary body swelling pushes the lens-iris forward
Onset	Slower; typically weeks to months	Sudden onset of symptoms	Rapid, often within days or weeks of starting drug
Bilateral or Unilateral	Usually bilateral if systemic steroids are used	Can be unilateral or bilateral	Often bilateral
Risk Factors	Family history of POAG, diabetes, high myopia	Narrow anterior chamber angles, older age, female, hyperopia	Idiosyncratic reaction, can occur in patients with open angles
Signs/Symptoms	Often asymptomatic until late stage	Severe eye pain, blurred vision, halos, headache, nausea	Blurred vision (myopia), eye pain, headache
Treatment	Discontinue steroid, add glaucoma drops, possibly laser or surgery	Discontinue drug, laser iridotomy, drops	Discontinue drug, cycloplegic drops, aqueous suppressants

Managing medication-induced glaucoma risk

For patients and healthcare providers, preventing drug-induced glaucoma requires careful consideration of a patient's overall health and eye anatomy. The key is communication and monitoring.

Patient strategies:

Maintain an accurate medication list: This includes all prescriptions, over-the-counter drugs, and supplements. Inform your eye doctor and other healthcare providers of any changes.
Get regular eye exams: If you are on high-risk medications, such as chronic steroids, regular eye pressure checks are vital for early detection.
Recognize warning signs: Be aware of symptoms like eye pain, blurred vision, halos around lights, and nausea, especially after starting a new medication.
Know your risk: If you have narrow angles or other risk factors, discuss prophylactic measures, like a laser iridotomy, with your ophthalmologist before starting at-risk medications.

Healthcare provider strategies:

Pre-screening high-risk patients: For patients with hyperopia, older age, or certain ethnicities, a quick screening tool like the oblique penlight test can help identify those with narrow angles.
Consider alternatives: When possible, opt for medications with lower glaucoma risk, or non-pharmacological therapies, especially for long-term use in high-risk patients.
Educate patients: Clearly explain the potential ocular side effects of prescribed drugs and emphasize the importance of reporting any vision changes.

Conclusion

While drug-induced glaucoma is a secondary condition, its potential for causing irreversible vision loss is a serious concern. The answer to "which drug induced glaucoma?" is not limited to a single class but includes a wide array of medications, most notably corticosteroids, anticholinergics, and sulfa-based drugs, each with a distinct mechanism of action. By fostering open communication between patients and medical professionals and promoting awareness of the risks, it is possible to mitigate the devastating effects of medication-induced glaucoma. Prompt identification and appropriate management, tailored to the specific mechanism, are essential for protecting vision and ensuring patient safety.

An excellent resource for both patients and clinicians on this topic is the American Academy of Ophthalmology, where you can find additional information on common drugs that can worsen glaucoma.

Frequently Asked Questions

Yes, many over-the-counter cold and flu remedies contain antihistamines and decongestants (e.g., diphenhydramine, pseudoephedrine) that have anticholinergic properties. These can cause pupil dilation, which may trigger an acute angle-closure glaucoma attack in individuals with narrow drainage angles.

Corticosteroids increase intraocular pressure by causing changes in the eye's drainage system, the trabecular meshwork, leading to decreased fluid outflow. This can happen with any form of steroid, including eye drops, oral tablets, and inhaled versions.

Symptoms depend on the type. Open-angle may have no early signs. Acute angle-closure symptoms include severe eye pain, blurred vision, seeing halos around lights, headache, nausea, and vomiting. If you experience these, seek immediate medical attention.

Yes, Topiramate (Topamax) is a sulfa-based medication known to cause a rare, idiosyncratic form of acute angle-closure glaucoma. It can cause ciliary body swelling that pushes the lens and iris forward, blocking drainage. This reaction is often bilateral and occurs shortly after starting the medication.

If you suspect your medication is causing glaucoma, contact your ophthalmologist or the prescribing physician immediately. For severe symptoms like acute eye pain or vision loss, go to the emergency room. Do not stop your medication suddenly without a doctor's advice.

In many cases, if the medication is discontinued promptly, the eye pressure and symptoms will resolve. However, prolonged exposure, especially with chronic steroid use or a severe acute attack, can lead to permanent optic nerve damage and vision loss.

Certain antidepressants, including tricyclics (like amitriptyline) and some SSRIs (like fluoxetine), have anticholinergic side effects that can dilate the pupil. In individuals with narrow drainage angles, this can trigger an acute angle-closure glaucoma attack.