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Last updated: 9/12/2024
Years published: 1994, 2003, 2016, 2024
NORD gratefully acknowledges Gioconda Alyea, MD (FMG), MS, National Organization for Rare Disorders and Sarwat Salim, MD, FACS, Professor of Ophthalmology, Chief, Glaucoma Service, Medical College of Wisconsin, for assistance in the preparation of this report.
Cogan-Reese syndrome is an extremely rare eye disorder characterized by a matted or smudged appearance to the surface of the iris, the development of small colored lumps on the iris (nodular iris nevi), the attachment of portions of the iris to the cornea (peripheral anterior synechiae) and/or increased pressure in the eye (glaucoma).
Secondary glaucoma may lead to vision loss. This disorder most frequently appears in young and middle-aged females, usually affecting only one eye (unilateral) and developing slowly over time.
Treatment focuses mainly on glaucoma management and may include eye drops and surgical procedures.
Cogan-Reese syndrome is one of the iridocorneal endothelial (ICE) syndromes, all of which usually affect one eye of young to middle-aged females. The ICE syndromes (essential iris atrophy, Chandlerโs syndrome and Cogan-Reese syndrome) are distinct from one another. However, since these disorders all affect the eye and some of their symptoms overlap, it may be difficult to distinguish between them. These variants may represent different stages of one disease. (For more information on Chandlerโs syndrome and essential iris atrophy, see the Related Disorders section of this report.)
Major characteristics of Cogan-Reese syndrome include:
The development of Cogan-Reese syndrome is gradual and may be preceded by symptoms of essential iris atrophy and/or Chandlerโs syndrome. The matted appearance of the iris and development of nodules on the iris distinguish Cogan-Reese syndrome from the other iridocorneal endothelial syndromes.
Other features of Cogan-Reese syndrome may include:
These changes may be responsible for the glaucoma that is characteristic of this disorder. People who develop glaucoma may also develop:
Cogan-Reese syndrome is a complex eye condition, and while its cause is not known, research has suggested some possible factors that might contribute to its development.
Some studies suggest that inflammation within the eye, particularly in the middle layer called the uvea, may be linked to Cogan-Reese syndrome. Uveitis is the medical term for this kind of inflammation.
Another theory is that the condition primarily affects the cells lining the cornea, known as the corneal endothelium. The impact on the iris (the colored part of the eye) might be a secondary effect or closely related to the corneal changes.
There is also evidence suggesting that a viral infection might trigger ICE syndrome, which includes Cogan-Reese syndrome. In one study, researchers found DNA from the Herpes simplex virus (HSV) in more than 60% of corneas from patients with ICE syndrome. Additionally, some studies have proposed a connection between ICE syndrome and the Epstein-Barr virus (EBV), another common virus that can affect various parts of the body.
Some scientists believe that the three types of ICE syndromes (Cogan-Reese syndrome, essential iris atrophy and Chandler syndrome) might represent different stages of the same underlying disease.
Cogan-Reese syndrome, like other ICE syndromes, causes significant changes in both the structure and function of the eye.
The cornea is made up of several layers that are carefully organized to keep it clear and transparent. The innermost layer, called the endothelial cell layer, normally acts as a barrier and pump, helping to maintain the corneaโs clarity. However, in ICE syndrome, these endothelial cells become abnormally tall and disorganized. Although they retain some features of normal cells, their altered structure disrupts the corneaโs ability to function properly. Over time, the damage and dysfunction caused by these abnormal cells can lead to a condition known as corneal decompensation. This occurs when the cornea can no longer stay clear and becomes cloudy or opaque, leading to vision problems.
One of the most serious complications of ICE syndrome, including Cogan-Reese syndrome, is secondary glaucoma. The abnormal endothelial cells can grow over the trabecular meshwork, which is the part of the eye responsible for draining fluid. Additionally, peripheral anterior synechiae (PAS) can form, which are adhesions between the iris and the cornea that further block fluid drainage. These blockages cause an increase in intraocular pressure (IOP), which is the key feature of glaucoma. If this pressure is not controlled, it can damage the optic nerve, leading to vision loss.
Cogan-Reese syndrome is a very rare disorder that predominantly affects females in the middle adult years, although cases have been reported in children. Most affected individuals are white. The male to female ratio ranges from 1:2 to 1:5. Family history usually shows no other affected family members.
When corneal edema is severe and makes it difficult to clearly see the structures in the front part of the eye (anterior chamber), a specialized imaging technique called in vivo confocal microscopy (IVCM) can be used.
IVCM is a noninvasive imaging method that allows doctors to see the cornea at a cellular level, providing detailed images of its layers. In people with ICE syndrome, IVCM can reveal abnormal corneal cells. These cells often look like epithelial cells (which normally line surfaces) but are found in the endothelial layer (the innermost layer of the cornea). These cells vary in size and shape, and they have bright cell borders with hyperreflective (very bright) nuclei, making them distinct and easier to identify.
This advanced imaging technique helps in diagnosing ICE early, which is key to managing the condition and preventing complications that could lead to significant vision problems.
The external appearance of the affected eye is abnormal in people affected with iridocorneal endothelial (ICE) including Cogan-Reese syndrome but will vary with the stage of the disease and clinical variant. The changes of the iris may not be seen without careful slit-lamp examination. A slit-lamp, which is a specialized magnifying microscope, is used to examine all the structures of the eye.
Ophthalmic examination of the corneal endothelium may reveal โhammered silverโ or โbeaten bronzeโ irregularities during slit-lamp examination, a reversal light pattern during specular microscopy, or changes in the iridocorneal angle on gonioscopy.
Specular microscopy is a noninvasive imaging technique that examines the corneaโs endothelial tissue to assess its health. It involves shining light onto the cornea and capturing the reflection off the endothelial layer. Gonioscopy is a routine procedure that measures the angle between the iris and the cornea, using a gonioscopy together with a slit lamp or operating microscope.
Cupping of the eye nerve (optic nerve) may be seen in patients with secondary glaucoma.
A thorough physical examination includes a slit-lamp examination, a careful exam of the angle with gonioscopy and tonometry or applanation. Techniques such as specular microscopy and IVCM can reveal the characteristic findings. Tonometry is a test to measure the fluid pressure inside the eyes and screen for glaucoma and evaluate the glaucoma treatment. Applanation tonometry uses a slit lamp with supports for your forehead and chin and a small cone that gently touches the cornea after it has been made numb with eye drops. This cone is used to measure the force (pressure) needed to temporarily flatten a part of the cornea.
Glaucoma may occur as a secondary disorder to Cogan-Reese syndrome. In general, glaucoma is one of the leading causes of blindness in the world. Glaucoma is characterized by increased pressure within the eye. If left untreated, the increased pressure affects the optic nerve, resulting in eventual blindness. In Cogan-Reese syndrome the mechanism of glaucoma is believed to be related to a cellular membrane secreted by the abnormal endothelial cells. This membrane covers the trabecular meshwork of the drainage angle, thereby obstructing aqueous outflow facility and elevating intraocular pressure. In the early stages, the angle may appear open clinically although it is covered by this transparent membrane. Over time, contraction of this membrane leads to peripheral anterior synechiae and secondary angle closure glaucoma.
The American Academy of Ophthalmology recommends a complete eye exam by the age of 40 or earlier for those at increased risk of glaucoma.
Treating Cogan-Reese syndrome focuses on managing symptoms and preventing further complications, particularly glaucoma.
The first step for managing glaucoma usually involves eye drops that reduce the amount of fluid the eye produces, helping to lower the pressure inside the eye. Commonly used drops include:
Some eye drops, like prostaglandin analogs, are generally avoided in ICE syndromes because they can trigger a viral infection in the eye.
If eye drops arenโt enough to control the pressure, surgery might be needed. Possible surgical options include:
For less severe swelling of the cornea, soft contact lenses and saline solutions can help reduce discomfort. However, when the swelling is more severe, surgical procedures may be necessary:
In some people, additional procedures can help with both cosmetic issues and vision:
Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.
For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:
Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: [email protected]
For information about clinical trials sponsored by private sources, contact:
www.centerwatch.com
For information about clinical trials conducted in Europe, contact:
https://www.clinicaltrialsregister.eu/
TEXTBOOKS
Durcan FJ. Cogan-Reese Syndrome. In: NORD Guide to Rare Disorders. Lippincott Williams & Wilkins. Philadelphia, PA. 2003:644.
Shields MB, Iridocorneal Endothelial Syndromes. In: NORD Guide to Rare Disorders. Lippincott Williams & Wilkins. Philadelphia, PA. 2003:649.
JOURNAL ARTICLES
Behera G, Nag TC, Khokhar SK, Sangaraju S. Electron microscopy in Cogan-Reese syndrome. Indian J Ophthalmol. 2022 Jul;70(7):2666-2668. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9426052/
Halhal M, Dโhermies F, Morel X, et al. [Iridocorneal endothelial syndrome. Series of 7 cases] J Fr Ophthalmol. 2001;24:628-34. French.
Teekhasaenee C, Ritch R. Iridocorneal endothelial syndrome in Thai patients: clinical variations. Arch Ophthalmol. 2000;118:187-92.
Ozdemir Y, Onder F, Cosar CB, et al. Clinical and histopathologic finding of iris nevus (Cogan-Reese) syndrome. Acta Ophthalmol Scand.1999;77:234-37.
Tester RA, Durcan FJ, Mamalis N, et al. Cogan-Reese syndrome. Progressive growth of endothelium over iris. Arch Ophthalmol. 1998;116:1126-27.
Huna R, Barak A, Melamed S. Bilateral iridocorneal endothelial syndrome presented as Cogan-Reese and Chandlerโs syndrome. J Glaucoma. 1996;5:60-62.
Wilson MC, Shields MB. A comparison of clinical variations of the iridocorneal endothelial syndrome. Arch Ophthamol. 1989;107:1465-68.
Makley TA, Kapetansky FM. Iris nevus syndrome. Ann Ophthalmol. 1988;20:311-15.
INTERNET
Facts about the Cornea and Corneal Disease. National Eye Institute (NEI). Last Update: June 20, 2024. Available at: https://www.nei.nih.gov/health/cornealdisease/#g Accessed Sept 12, 2024.
Das S, Tur K, Tripathy K. Iridocorneal Endothelial Syndrome. [Updated 2023 Aug 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK594227/ Accessed Sept 12, 2024.
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