WHAT IS A UVEAL CYST?
Uveal cysts are fluid filled, round to oblong structures that are more or less densely pigmented, which gives them a brown to yellowish color. Cysts usually occur suddenly and may be free floating or attached to the iris. Cysts can vary in size, shape, and number. They originate from the iris or the ciliary body, which is a structure behind the iris. Some cysts appear quite dense and can easily be mistaken for melanoma. Examination with a slit-lamp biomicroscope allows a distinction between those two conditions. In most cases uveal cysts are considered benign.
Cysts may persist for month or years before they rupture. The rupturing of cysts is not painful. A pigmented spot might be seen on the surface of the lens or the inner surface of the cornea.
WHAT CAUSES UVEAL CYSTS?
Cysts develop spontaneously. A specific cause is not known. However, inheritance probably is a factor in some breeds.
ARE CERTAIN BREEDS MORE LIKELY TO DEVELOP UVEAL CYSTS?
Yes, Golden Retrievers, Boston Terriers, and Labrador Retrievers are common breeds to develop uveal cysts. The condition is also sometimes diagnosed in cats.
WHAT ARE POTENTIAL COMPLICATIONS WITH UVEAL CYSTS?
Smaller cysts usually do not cause any problems. However, the presence of multiple or bigger cysts can be associated with vision impairment. In Golden Retrievers uveal cysts are commonly associated with anterior uveitis (inflammation inside the eye) bearing the risk to develop glaucoma, corneal edema and ulceration.
WHAT ARE THE TREATMENT OPTIONS?
No treatment is necessary unless the pupil is obstructed and vision is impaired. Cysts can be aspirated under anesthesia with a fine needle or deflated with a diode laser.