Corneal Hydrops: Sudden Eye Swelling Caused by a Split in the Cornea
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer
Corneal hydrops is sudden swelling of the cornea caused by a split in Descemet's membrane that lets eye fluid leak in, causing a hazy white spot, sudden vision loss, pain and light sensitivity [1]. It usually affects people with keratoconus [1]. It is treated with eye drops or, for larger tears, surgery, though most episodes heal with a corneal scar [1].
What the research says
Corneal hydrops is uncommon, and it mostly affects younger men with keratoconus. A UK national prospective study identified 73 new cases of acute corneal hydrops in keratoconus over about 13 months. Among 64 confirmed cases, the median age at onset was 31.9 years and 75% were male. South Asian and Black patients were over-represented compared with the general population (P < 0.001). The minimum annual incidence was about 1.43 per 1,000 people with keratoconus, and 20.3% of patients with follow-up had decided on a corneal transplant by 6 months (PubMed: Barsam et al., Eye, 2015) [2].
Edema usually settles on its own, but a scar is common. A review of the literature describes acute hydrops as usually self-limiting, with edema typically resolving after about 3 months, yet often leaving a vision-impairing scar that can bring forward the need for corneal transplantation. Newer treatment regimens have shortened the duration of edema and improved graft survival. This is a narrative review, not a pooled analysis (PubMed: Fan Gaskin et al., Am J Ophthalmol, 2014) [3].
Imaging helps choose the treatment. In 9 eyes of 7 patients with Descemet's membrane detachment and severe corneal edema (from several causes, not only keratoconus), anterior segment OCT showed the detachment in every eye. Two eyes were treated conservatively, 6 with an air or gas bubble, and 1 with a corneal transplant; all but one air treatment succeeded. The sample was very small (PubMed: Zhou et al., Ophthalmologica, 2012) [4].
What Is Corneal Hydrops?
Corneal hydrops is the medical term for swelling in the cornea, the clear front surface of the eye. The swelling begins when a split forms in a layer of the cornea called Descemet's membrane. That split allows fluid inside the eye to leak into an inner corneal layer called the stroma [1].
The swelling can also trigger an inflammatory response. This inflammation may produce a cloudy or hazy spot in the cornea. To others, the cloudiness looks like a white spot on the eye, and to you, it can make vision blurry [1].
Because the condition typically happens suddenly, you may also hear the term acute corneal hydrops [1]. It is a complication of keratoconus or any corneal disease that changes the shape of the cornea [1]. These shape-affecting diseases fall under the broader term "corneal ectasias."
The swelling may get better without treatment, but you should not make that decision on your own [1]. An eye care provider can confirm the diagnosis and recommend the safest way forward.
How Common Is It?
An estimated 0.2% to 2.8% of people with keratoconus develop corneal hydrops [1]. One estimate puts the U.S. rate of keratoconus at 55 people per 100,000 individuals [1]. The condition happens more often in men and usually strikes in your 20s or 30s [1].
Key Fact | What the Evidence Shows |
Definition | Sudden swelling of the cornea from fluid leaking into the stroma |
Underlying cause | A split in Descemet's membrane |
Most common underlying condition | Keratoconus and other corneal ectasias |
Who it affects | 0.2%–2.8% of people with keratoconus; more often men |
Typical age | 20s and 30s |
Contagious? | No — it cannot be passed from person to person |
What are the signs and symptoms of corneal hydrops?
Some people with corneal hydrops have no symptoms at all [1]. When symptoms do appear, they tend to arrive suddenly, which is why prompt evaluation matters.
Symptom | What It Feels or Looks Like |
Sudden worsening of vision | Vision deteriorates quickly rather than gradually |
Hazy white spot | A cloudy spot appears in the eye itself |
Eye pain | Discomfort that can range from mild to severe |
Light sensitivity | Extreme sensitivity to light (photophobia) |
Red eyes | Noticeable redness in the affected eye |
Watery eyes | Excess tearing or watering |
Contact lens problems | Lenses become uncomfortable or no longer fit properly |
Eye pain, sudden vision changes, and light sensitivity often show up together. If you wear contact lenses, you may notice that wearing them becomes difficult or uncomfortable — one of the earliest practical warning signs.
What causes corneal hydrops and who is at risk?
Corneal hydrops is not contagious, and its main causes are thinning of the cornea, distortion of the cornea's shape (corneal ectasia) and repeated eye rubbing [1]. Healthcare providers believe the main causes are:
Thinning of the cornea. A thinner cornea is weaker and more likely to split.
Distortion of the cornea's shape. This distortion is known as corneal ectasia.
Repeated eye rubbing. Rubbing stresses the already thin, distorted cornea.
Who Is at Higher Risk?
Risk Factor | Why It Raises Risk |
A corneal ectasia disease (especially keratoconus) | Directly weakens and distorts the cornea |
Atopy | A tendency toward allergies or an extreme immune response |
Down syndrome | Associated with higher rates of corneal ectasia |
Eye rubbing is the most modifiable risk factor on this list. People with seasonal allergies or other conditions that make the eyes itchy and tired should resist the urge to rub.
What are the complications of corneal hydrops?
Corneal hydrops may impair your vision, and the risk of more serious complications, such as abnormal blood vessel growth or perforation, grows with time. The risk of more serious complications grows with time.
Swelling that lasts for a long time (corneal edema) can result in neovascularization — blood vessels growing in areas of the eye where they should not grow [1]. In severe cases, untreated corneal hydrops can also cause the growth of abnormal blood vessels in the eye. Larger tears with more swelling may result in perforation, meaning holes in the cornea.
Complication | When It Occurs |
Impaired vision | During the episode itself |
Neovascularization | When swelling lasts a long time |
Abnormal blood vessel growth | In severe, untreated cases |
Corneal perforation (holes) | With larger tears and more swelling |
How Is Corneal Hydrops Diagnosed?
An eye care provider starts by asking about your medical history and symptoms, then performs a complete eye exam [1]. Several specialized tests can confirm the diagnosis and guide treatment.
Test | What It Does |
Complete eye exam | Assesses overall eye health, symptoms, and history |
Anterior segment OCT (optical coherence tomography) | Diagnoses corneal hydrops and monitors healing |
Ultrasound biomicroscopy | Determines whether Descemet's membrane has split |
Tomography | Measures the cornea's shape and thickness |
Seidel test | Determines whether aqueous fluid is leaking from the cornea |
Anterior segment optical coherence tomography does double duty — it confirms the diagnosis and then tracks healing over time [1]. The Seidel test is especially direct: it shows whether fluid is actively leaking from the cornea [1].
How Is Corneal Hydrops Treated?
Corneal hydrops is treated with topical medications for many small tears with little swelling, while surgery is recommended for larger tears with more significant swelling. You may also need treatment for the underlying disease that caused the hydrops in the first place [1]. For many small tears with little swelling, topical medications are usually enough [1]:
Medication | Purpose |
Hypertonic saline | Pulls fluid out of the stroma |
Steroids | Decreases inflammation |
Eye-pressure medications | Reduces elevated intraocular pressure |
Antibiotics | Prevents infection, if needed |
Pupil-dilating drops | Eases pain by dilating the pupils |
Surgery is recommended when tears are larger and swelling is more significant, because large tears can result in perforation [1]. If the tear reaches that point, surgical repair becomes the safer option.
What is the outlook for corneal hydrops?
Acute corneal hydrops is treatable. However, in most cases, the episode results in a corneal scar that may require additional treatments — including surgery — down the road [1]. You will need follow-up appointments while recovering and for a period afterward [1]. These visits help your provider determine the best long-term plan for your cornea.
Can Corneal Hydrops Be Prevented?
Prevention depends heavily on whether you have keratoconus. If you do, an eye care provider can assess whether you are a good candidate for a treatment called crosslinking. Crosslinking prevents the progression of keratoconus and, in turn, prevents corneal hydrops [1]. That said, in some cases acute corneal hydrops cannot be prevented as a complication of keratoconus and other corneal diseases [1].
If you have seasonal allergies or any other condition that causes itchy or tired eyes, you can reduce your risk by avoiding eye rubbing [1]. That single habit is the most controllable prevention step available.
Prevention Approach | How It Helps |
Crosslinking (for keratoconus) | Stops corneal disease progression that leads to hydrops |
Avoiding eye rubbing | Removes mechanical stress on the thin cornea |
Managing allergic eye conditions | Reduces itch-driven rubbing |
How can people live well with corneal hydrops?
Day-to-day self-care centers on two habits: do your best to stop rubbing your eyes, and keep your scheduled eye appointments [1]. Both directly reduce the risk of recurrence and complications.
When Should You Seek Emergency Care?
Ask your provider for specifics about when to call or visit the emergency room. In general, seek care right away when:
You lose vision
You have sudden eye pain
You have infection symptoms such as fever
You notice unexpected eye discharge [1]
Can You Wear Contacts?
Wearing contact lenses with corneal hydrops may be difficult or uncomfortable. Once you know you have the condition, you will probably need to stop wearing your contacts. You should be able to resume wearing them after treatment [1].
Conclusion
Corneal hydrops is a sudden, dramatic eye event — fluid leaks through a split in the cornea and causes rapid swelling, often with visible clouding and vision loss. The good news is that it is treatable, and most people recover with the help of eye drops or surgery. The lasting cost is usually a corneal scar, which may need additional attention later.
The practical takeaway: if you have keratoconus or another corneal ectasia, ask your eye care provider about crosslinking, stop rubbing your eyes, and seek prompt care whenever eye pain or sudden vision changes appear. Quick treatment shortens the episode and protects your long-term vision.
Learn more: If you are researching corneal conditions, see our guide to corneal disease.
Frequently Asked Questions
1. What is corneal hydrops?
Corneal hydrops is the medical term for swelling in the cornea. It happens when a split in Descemet's membrane allows fluid inside the eye to leak into the stroma, an inner corneal layer. Because it occurs suddenly, it is often called acute corneal hydrops.
2. What causes corneal hydrops?
Healthcare providers believe causes include thinning of the cornea, distortion of the cornea's shape (corneal ectasia), and repeated eye rubbing. It is not contagious and cannot be passed from person to person.
3. Who gets corneal hydrops?
An estimated 0.2% to 2.8% of people with keratoconus develop corneal hydrops. It happens more often in men and usually occurs in your 20s or 30s. People with atopy or Down syndrome are at higher risk.
4. What are the symptoms of corneal hydrops?
Symptoms include vision that worsens suddenly, a hazy white spot in the eye, eye pain, extreme light sensitivity, red eyes, watery eyes, and problems with contact lenses. Some people have no symptoms at all.
5. Is corneal hydrops related to keratoconus?
Yes. Corneal hydrops is a complication of keratoconus or any corneal disease that changes the shape of the cornea. These conditions are grouped under the term "corneal ectasias."
6. How is corneal hydrops diagnosed?
An eye care provider takes a medical history, performs a complete eye exam, and may order anterior segment OCT, ultrasound biomicroscopy, tomography, and a Seidel test to confirm fluid leakage.
7. How is corneal hydrops treated?
Small tears with little swelling are treated with topical medications such as hypertonic saline, steroids, eye-pressure drugs, antibiotics, and pupil-dilating drops. Larger tears may require surgery to prevent perforation.
8. What is the outlook for corneal hydrops?
Acute corneal hydrops is treatable, but most cases result in a corneal scar that may need additional treatments, including surgery. Follow-up appointments guide the long-term plan.
9. Can corneal hydrops be prevented?
People with keratoconus may be candidates for crosslinking, which prevents disease progression and corneal hydrops. In some cases, prevention is not possible, but avoiding eye rubbing always reduces risk.
10. Can I wear contact lenses with corneal hydrops?
Wearing contacts during corneal hydrops is usually difficult or uncomfortable, and you will probably need to stop after diagnosis. Most people can resume wearing contacts after treatment.
11. When should I go to the emergency room?
Seek immediate care for loss of vision, sudden eye pain, infection symptoms such as fever, or unexpected eye discharge. When in doubt, contact your eye care provider promptly.
Related Reading
Learn more in our guide to Corneal Cross-Linking (CXL): Purpose, Procedure, Risks and Recovery.
References
Cleveland Clinic. Corneal Hydrops. Cleveland Clinic. February 14, 2023. https://my.clevelandclinic.org/health/diseases/24783-corneal-hydrops
Barsam A, Petrushkin H, Brennan N, et al. Acute corneal hydrops in keratoconus: a national prospective study of incidence and management. Eye (Lond). 2015;29(4):469-474. doi:10.1038/eye.2014.333. PMID: 25592120.
Fan Gaskin JC, Patel DV, McGhee CNJ. Acute corneal hydrops in keratoconus - new perspectives. Am J Ophthalmol. 2014;157(5):921-928. doi:10.1016/j.ajo.2014.01.017. PMID: 24491416.
Zhou SY, Wang CX, Cai XY, Liu YZ. Anterior segment OCT-based diagnosis and management of Descemet's membrane detachment. Ophthalmologica. 2012;227(4):215-222. doi:10.1159/000334946. PMID: 22261666.
Medical Disclaimer
This article is for informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read here.
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