Perfluorohexyloctane ophthalmic solution, marketed under the brand name Miebo, is a prescription eye drop used to treat the signs and symptoms of dry eye disease (DED), particularly for patients with meibomian gland dysfunction (MGD). Unlike many dry eye treatments that focus on increasing tear production or reducing inflammation, perfluorohexyloctane forms a protective, anti-evaporative layer on the surface of the eye. Its single-ingredient, preservative-free formulation contributes to its favorable safety profile. However, like any medication, it can cause side effects. This guide details the adverse events identified during clinical trials, helping patients know what to expect.
Common and Transient Side Effects
The most frequently reported side effects associated with perfluorohexyloctane ophthalmic solution are generally mild and transient, meaning they are temporary and resolve on their own. Based on pooled data from pivotal Phase 3 clinical trials (GOBI and MOJAVE), these common reactions affect a small percentage of users.
- Blurred Vision: This is the most common adverse event, reported by 1–3% of patients. It is typically described as mild and transient, often occurring shortly after instillation and clearing up quickly. Patients are advised to wait until their vision clears before driving or operating machinery.
- Eye Redness (Conjunctival and Ocular Hyperemia): A small percentage of patients experience redness in or around the eyes. This effect is usually mild and temporary.
Less Common Adverse Events
While less frequent than blurred vision or eye redness, other ocular side effects have been reported during clinical studies. The incidence of these events is low, and most are mild or moderate in severity.
- Allergic Conjunctivitis: Inflammation of the conjunctiva due to an allergic reaction has been observed in some patients.
- Eye Irritation or Discharge: A small number of patients have reported eye irritation or discharge. In one long-term study, one patient discontinued treatment due to severe eyelid irritation that was possibly treatment-related.
- Increased Lacrimation (Tearing): Some individuals have experienced increased tear production.
- Vitreous Detachment: This was noted in a long-term extension study (KALAHARI) but was not considered treatment-related by investigators.
- Chalazion: A chalazion, or a small lump on the eyelid, was reported in one patient in a long-term study and was considered treatment-related.
Potential for Serious Side Effects
Serious adverse events with perfluorohexyloctane ophthalmic solution are rare. However, it is important for patients to be aware of the signs of a severe reaction and know when to seek immediate medical attention.
- Severe Allergic Reaction: Though uncommon, a severe allergic reaction (anaphylaxis) is possible with any medication. Symptoms may include hives, difficulty breathing, swelling of the face, lips, tongue, or throat, or a rash. If any of these symptoms occur, discontinue use and seek emergency medical care immediately.
- Other Serious Eye Symptoms: Seek urgent medical care if you experience a sudden loss of vision, severe eye pain or swelling, tunnel vision, or see halos around lights.
Perfluorohexyloctane vs. Other Dry Eye Treatments: Side Effect Profile
To put the side effects of perfluorohexyloctane into context, it is helpful to compare its profile with other common dry eye treatments. Its preservative-free, single-ingredient formula is a key differentiator.
| Feature | Perfluorohexyloctane (Miebo) | Cyclosporine (Restasis/Cequa) | Lifitegrast (Xiidra) | Preserved Artificial Tears |
|---|---|---|---|---|
| Mechanism | Forms an anti-evaporative layer | Increases tear production via immunomodulation | Inhibits T-cell activation to reduce inflammation | Provides temporary lubrication |
| Common Ocular AEs | Blurred vision (1-3%), eye redness (1-3%) | Ocular burning, stinging, itching | Instillation site irritation, reduced visual acuity | Preservative-induced irritation or toxicity over time |
| Less Common Ocular AEs | Allergic conjunctivitis, increased lacrimation | Foreign body sensation, discharge, blurred vision | Dysgeusia (unpleasant taste), headache | Allergic reactions to preservatives |
| Systemic Exposure | Minimal systemic absorption | Minimal systemic absorption | Minimal systemic absorption | Minimal systemic absorption |
| Risk of Irritation from Preservatives | None (preservative-free) | Minimal (some formulations are preservative-free) | Minimal (preservative-free) | Yes (Benzalkonium chloride, etc.) |
Conclusion
Perfluorohexyloctane ophthalmic solution represents a novel approach to treating dry eye disease by addressing the evaporative component. Based on extensive clinical trial data, its safety profile is favorable, with a low incidence of adverse events. The most common side effects are mild and transient blurred vision and eye redness, affecting a small number of patients. As a preservative-free medication, it avoids the irritation sometimes caused by preservatives in other eye drop formulations. While severe allergic reactions are possible, they are extremely rare. Patients should always use the medication as prescribed and consult their healthcare provider for any questions or concerns about potential side effects. For official prescribing information, you can visit the Miebo website.
