Iridocorneal endothelial (ICE) syndrome is a group of rare, progressive eye conditions that can lead to glaucoma. ICE syndrome almost always involves the movement of endothelial cells off the cornea onto the iris. 

These flat, specialized cells line the back surface of the cornea, the clear outermost cover of your eye, and they help control fluids to the cornea. When endothelial cells leave, the cornea can swell, the iris and pupil can become distorted, and shifted cells can block proper drainage, leading to glaucoma.*

Are there different types of ICE syndrome?

According to the American Academy of Ophthalmology, there are three variants of the disease: Chandler’s syndrome (CS), essential/progressive iris atrophy, and iris nevus (Cogan-Reese) syndrome.

• Chandler’s syndrome is the most common—representing approximately 50% of all ICE cases. It typically involves greater corneal swelling than the other types. 
• Essential/progressive iris atrophy may present in several ways, including a thinning of the iris, a hole in the iris, or an iris shape that is other than round. 
• Iris nevus (Cogan-Reese) syndrome is usually identifiable by tan-colored nodules and/or pigmented lesions on the iris.

What causes ICE syndrome?

While it appears that being a female between the ages of 20 and 50 is a risk factor for developing ICE, the actual causes of the disease are not yet known. 

Some scientists think it may be triggered by a herpes simplex or Epstein-Barr virus (EBV) infection, which leads to low-grade inflammation that activates the unusual behavior of the cells. ICE syndrome patients have been found to have higher percentages of herpes simplex virus in their DNA compared to those without ICE. 

Unlike many chronic diseases, ICE syndrome rarely runs in families and is not directly associated with any other eye-related diseases nor systemic diseases in general.

What are the symptoms of ICE syndrome?

ICE usually affects only one eye. The swelling of the cornea caused by the shifting of endothelial cells can also cause:

• Blurred vision
• Pain
• Visible distortion of both your iris and pupil
• Angle-closure glaucoma

How is ICE syndrome diagnosed?

In addition to the readily visible changes to your cornea, pupil, and iris, ICE is diagnosed by a comprehensive eye exam that includes:

• Visual field test
• Intraocular pressure (IOP) measurement
• Slit-lamp exam
• Dilated fundus (the part of the eyeball opposite the pupil) exam
• Gonioscopy (to check your eye’s drainage angle) 

What is the treatment for ICE syndrome?

There is no known way to stop the progression of ICE. Treatment usually focuses on managing glaucoma with either medication or surgery to relieve internal eye pressure. 

Medications may include topical therapies such as eye drops containing:

• Beta blockers 
• Alpha-agonists 
• Carbonic anhydrase 

Saline solutions and gels may also be prescribed to reduce corneal swelling.

If surgery is deemed necessary, your doctor will likely recommend either:

• Trabeculectomy (to remove part of your eye’s drainage network)
• Tube shunt implantation (to redirect eye fluid drainage away from the blockage)

Long-term outcomes have been slightly better with drainage implants than with trabeculectomy.

Regardless of the procedure used, ICE patients generally require multiple surgeries to maintain a stable IOP. A cornea transplant is also possible in certain cases.

*Aref, A. A., Oldham, G. W., Akkara, J. D., Hossain, K., et al. (2019, Sep. 15). Iridocorneal Endothelial Syndrome (ICE). American Academy of Ophthalmology EyeWiki. https://eyewiki.aao.org/Iridocorneal_Endothelial_Syndrome_and_Secondary_Glaucoma

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