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Adhesions of the Iris of the Eye in Cats

Synechiae are adhesions between the iris and other structures in the eye. They are the result of inflammation in the iris and are particularly common with anterior uveitis (inflammation of the dark tissues of the eye) and trauma to the eye.

Synechiae can occur in both dogs and cats. If you would like to learn how this type of eye problem affects dogs, please visit this page in the petMD health library.

Symptoms and Types

Synechiae may be anterior or posterior.

• Anterior synechiae is defined as an adhesion between the iris and the cornea. The cornea is the transparent cover of the front of the eye.
• Posterior synechiae is the adherence of the iris to the capsule surrounding the lens of the eye.

Symptoms seen with synechiae include:

• Squinting
• Corneal lesions, such as ulcers
• Excessive tearing
• Glaucoma
• Variation in the color of the iris
• Opacity of the lens
• Uveitis
• Decreased papillary reaction to light

Causes

• Cat fight injury
• Chronic infection
• Corneal ulcer
• Foreign body injury to the eye
• Hyphema (bleeding in the front part of the eye)
• Penetrating wounds to the eye
• Surgery

Diagnosis

Diagnosis is based on an ophthalmic examination, which involves examining the structures of the eye. In addition, dyes may be used on the cornea to detect corneal injuries. Tonometry may be performed to measure the intraocular pressure (the pressure within the eyeball.)