Key takeaways
Synechiae in cats are adhesions between an eye’s iris (colored ring) and either the cornea (outer layer) or lens (located behind the iris).
- Synechiae develop as a result of ocular inflammation and can be caused by an injury or infection
- While not usually dangerous, synechiae can be painful; especially when accompanied by glaucoma or uveitis
- Severe synechiae is called iris bombe, which can lead to ocular pressure and may result in blindness
- Synechiae present with misshapen pupils or irises, redness in an affected eye, and vision changes
- Synechiae are diagnosed with an ophthalmic exam
- Treatment is often unneeded, unless synechiae are associated with active uveitis or secondary glaucoma develops
- When indicated, treatment includes medication to reduce eye pressures or surgery
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A closer look: Synechiae in Cats
An iris is the colored ring in an eye. The cornea is the clear outer layer of an eye, and a lens sits behind the iris and directs light within the eye. If the iris connects to and sticks to either the cornea or lens, it is identified as posterior or anterior synechiae respectively.
Synechiae may obstruct natural fluid movement and drainage within an eye. Fluid buildup leads to increased pressure, which causes pain and may damage ocular structures.
Synechiae are not usually cause for medical concern, except in cases of iris bombe.
If the iris adheres to the lens with 360 degree connection, then ocular fluid cannot flow properly through the eye, and pressure increases.
Iris bombe is painful, and may result in blindness. Any cat presenting with sudden vision changes or ocular pain requires emergency medical attention.
Risk factors
Possible causes
Causes of synechiae include:
- Inflammation in the front of an eye (uveitis)
- Injury to the eye
- Side effects of a recent surgery
Main symptoms
Symptoms of synechiae include:
- Abnormal iris or pupil shape
- Redness
- Loss of vision
- Discomfort or pain
Testing and diagnosis
Diagnostics include:
- A physical examination
- An ophthalmic (eye) exam
- Tonometry
Steps to Recovery
Treatment is often unnecessary, unless iris bombe develops or is at risk of developing. In these cases, medication to reduce eye pressure or surgery is indicated. If uveitis (eye inflammation) is suspected, antibiotics, antifungals, or anti-inflammatories may be indicated.
Prognosis for synechiae on their own is excellent, with most cases not requiring treatment. Cats showing symptoms of synechiae that continue to have painful eyes with squinting or vision changes may have an active inflammatory process occurring within their eye that requires further treatment.
In cases where significant adhesion has occurred, routine examination of the eye to measure ocular pressure may be necessary to quickly identify any changes that may require treatment.
Prevention
There are no ways to prevent synechiae. Seeking immediate medical attention at the first sign of ocular abnormalities affords the best chances for treatment and an improved prognosis.
Synechiae are not contagious.
Is Synechiae in Cats common?
Synechiae are not common, but are more common alongside injuries or uveitis.
Typical Treatment
- Medications to reduce ocular pressure
- Antifungal medication
- Antibiotics
- Surgery
