What You Need to Know About Iyuzeh Side Effects

Iyuzeh (preservative-free Latanoprost) is a once-daily eye drop used to lower eye pressure in people with open-angle glaucoma or ocular hypertension. Like all medications, it comes with potential side effects — some mild and temporary, others that need medical attention.

This guide covers the most common and serious side effects of Iyuzeh based on FDA labeling, so you know exactly what to watch for and when to contact your doctor.

What Is Iyuzeh?

Iyuzeh is the first preservative-free formulation of Latanoprost, a prostaglandin analog that lowers intraocular pressure (IOP). It's made by Thea Pharma and was FDA-approved in November 2022. Unlike generic Latanoprost (brand name Xalatan), Iyuzeh does not contain benzalkonium chloride (BAK), a preservative known to irritate the eye surface over time.

For a deeper dive into how this medication works, see our guide on how Iyuzeh works. For full details on dosage and uses, read What Is Iyuzeh?

Common Side Effects

These side effects are relatively frequent and usually mild. Most improve as your eyes adjust to the medication over the first few weeks:

• Eye redness (conjunctival hyperemia) — The most commonly reported side effect. Your eyes may look bloodshot or pinkish, especially right after using the drops.
• Eye irritation — A stinging or burning feeling when you put in the drops. This is usually brief.
• Eye itching (pruritus) — Mild itchiness in or around the eye.
• Foreign body sensation — A feeling like something is in your eye, even though nothing is there.
• Blurred vision — Temporary blurriness right after putting in the drops. This usually clears within a few minutes.
• Watery eyes (increased lacrimation) — Your eyes may tear up more than usual after application.

Because Iyuzeh is preservative-free, some of these irritation-related side effects may actually be milder compared to preserved Latanoprost products that contain BAK.

Serious Side Effects

These side effects are less common but more significant. Contact your eye doctor if you notice any of the following:

Changes to Your Eye Color

Increased brown pigmentation of the iris — Latanoprost can gradually change the color of your iris by increasing the amount of brown pigment. This is most noticeable in people with mixed-color eyes (green-brown, blue-brown, or gray-brown). The change happens slowly over months to years and may be permanent. If you're only using Iyuzeh in one eye, the treated eye may end up a different color from the untreated eye.

Changes to Your Eyelids and Eyelashes

• Eyelid skin darkening — The skin around your eye may darken. This is usually reversible if you stop the medication.
• Eyelash changes — Your eyelashes may grow longer, thicker, darker, or increase in number. While some people consider this a cosmetic benefit, it can cause discomfort if lashes become misdirected and poke the eye.
• Misdirected eyelashes — Lashes that grow in the wrong direction and irritate the eye surface.

Eye Inflammation and Swelling

• Intraocular inflammation (iritis/uveitis) — Inflammation inside the eye that can cause pain, light sensitivity, and blurred vision.
• Macular edema — Swelling in the center of the retina that can affect your central vision. This is more likely in patients who are aphakic (no natural lens), pseudophakic with a torn posterior lens capsule, or who have other risk factors.
• Corneal edema or erosions — Swelling or damage to the clear front surface of the eye.

Herpes Reactivation

Reactivation of herpes simplex keratitis — If you have a history of herpes simplex infection in your eye, Latanoprost can potentially trigger a flare-up. Tell your doctor before starting Iyuzeh if you've ever had this condition.

Specific Populations

Pregnant or Breastfeeding

The safety of Iyuzeh during pregnancy and breastfeeding has not been well established. Animal studies have shown some risk. Talk to your doctor about the risks and benefits if you are pregnant, planning to become pregnant, or breastfeeding.

Children

Safety and effectiveness of Iyuzeh have not been established in pediatric patients.

Contact Lens Wearers

Remove your contact lenses before using Iyuzeh and wait at least 15 minutes before putting them back in. The medication and single-dose container contents should not come into contact with your lenses.

People Using Multiple Eye Drops

If you use other eye drops, wait at least 5 minutes between each type. This prevents one drop from washing out the other. For information on drug interactions, see our guide on Iyuzeh drug interactions.

How to Manage Common Side Effects

Here are practical tips for dealing with the milder side effects:

• For eye redness — This often improves over the first few weeks. If it bothers you, using the drops in the evening (as directed) means redness is less noticeable since you'll be sleeping.
• For stinging or irritation — Make sure the drops are at room temperature. Cold drops can sting more. Close your eyes gently after application and press lightly on the inner corner of your eye (punctal occlusion) for 1–2 minutes.
• For blurred vision — Avoid driving or operating machinery right after putting in the drops. Wait until your vision clears.
• For watery eyes — Blot gently with a clean tissue. This usually resolves within a few minutes.
• For eyelash changes — Keep lashes trimmed if they become uncomfortable. Report misdirected lashes to your doctor.

Wiping any excess medication off your skin around the eyes can help reduce eyelid darkening and minimize skin absorption.

When to Call Your Doctor

Contact your eye doctor right away if you experience:

• Sudden eye pain or significant increase in discomfort
• Sudden decrease in vision or loss of vision
• Severe redness that doesn't improve
• Signs of infection (discharge, crusting, severe swelling)
• Light sensitivity with eye pain (possible inflammation)
• Distorted or blurry central vision (possible macular edema)

Don't stop using Iyuzeh without talking to your doctor first. Stopping suddenly can cause your eye pressure to rise, which could lead to optic nerve damage and vision loss.

Final Thoughts

Most people tolerate Iyuzeh well, especially since the preservative-free formula eliminates one common source of eye irritation. The most frequent side effects — redness, mild irritation, and watery eyes — are usually manageable and often improve with time.

The more serious effects, like iris color changes and macular edema, are less common but worth knowing about. Regular follow-up appointments with your eye doctor are the best way to catch any problems early.

If you're having trouble finding Iyuzeh at your pharmacy, Medfinder can help you locate pharmacies that have it in stock. And if cost is a concern, check out our guide on how to save money on Iyuzeh.