Iris Cysts In Dogs – Symptoms & Treatment

Iris cysts (sometimes referred to as iridociliary cysts or uveal cysts) are usually benign and require no treatment. However, occasionally they may be large enough to hamper the function of the eye or interfere with vision or they can also be an initial sign of pigmentary uveitis (a progressive blinding disease)

The term cyst refers to a structure lined by epithelial cells (resembling a balloon) that may be filled with liquid, gaseous, or semisolid substances. When these occur in the eye, they most often originate from the vascular tissues of the eye, called the uveal tract.

The uveal tract comprises the iris (the structure that gives the eye its color), the ciliary body (tissue containing muscles that change the shape of the lens), and the choroid (tissue filled with blood vessels). The uveal structure easiest to see is the ‘iris’ due to its colored nature (blue, brown, green, golden, etc.)

A cyst can originate from epithelial cells of the inner ciliary body or posterior pigmented iris. They can be single or multiple, unilateral or bilateral, variably sized or variably pigmented, circular or oval, located within the posterior chamber or adhered to the pupillary margin or free-floating within the fluid of the eye.

• Alterations in vision
• Change in behavior 
• Eventual development of glaucoma
• Obstruction of the visual axis
• Recurrent iritis
• Cataract

No treatment is necessary until the cysts are stable. When vision is getting impaired or the pupil is obstructed or any other secondary complications are observed, step-wise medical intervention is required.

Laser treatment: photodisruption (neodymium in yttrium aluminum garnet) or photocoagulation (argon)

Fine-needle aspiration and injection of a sclerosing agent (5-fluorouracil, ethanol, and mitomycin C )

Surgical options: Excision of the cyst alone or iridocyclectomy or as part of a sector iridectomy.

Always be aware of the risk factors associated with Iris cysts. Educate yourself about the signs and symptoms.

Get suggestions from your vet regarding the prognosis of this condition.

Regularly monitor the symptoms and contact your vet if you note any significant new symptoms or changes in their vision.

Iris Cysts etiology is poorly understood. Specific causes are not yet known. However, Hereditary is, perhaps a factor in some breeds and it is better to evaluate the affected dogs before breeding or at least before getting a dog from a susceptible lineage and get the eye checks done.

Golden Retriever, Labrador Retriever, Boston Terrier, Bulldog, Great Dane

Causes:

Cysts may be congenital or acquired.

• Congenital cysts: This is a hereditary anomaly in the eye and affected dogs are born with the cysts.
• Acquired cysts: This is a result of uveitis (inflammation inside the eye) and trauma to the eye.

Acquired cysts are of two types:

Primary cysts: These occur in iris stroma or iris pigment epithelium

Secondary cysts: these are classified according to the pathophysiology. Implantation cysts(presence of a foreign body), uveitic, drug-induced, parasitic, tumor-induced, and cysts related to systemic disorders

Diagnosis:

• Schirmer Tear Test (STT)
• Fluorescein staining test
• Tonometry
• aesthesiometry,
• an electroretinogram
• ultrasound

Morbidity:

Secondary cysts are more prevalent than primary cysts. Male dogs are more reported with secondary cysts, which are likely linked to implantation cysts and trauma.

Mortality:

Congenital cysts are from birth or present themselves from puppyhood. Typically Acquired cysts occur later in life and hardly ever need treatment. The mortality rate is almost zero.

Prognosis:

The outcome depends on the size and nature of the iris cyst. In general, primary cysts have an excellent while secondary cysts have a ‘not so bad’ prognosis.

Of the primary cysts, stromal cysts have a poor prognosis compared to pigment epithelial cysts.

Other reasons for poor prognosis include congenital presentation, l reduced visual acuity at presentation, big size (takes up more than 50% of anterior chamber), and apposition to cornea or lens. There are no racial and sex-related differences affecting the prognosis.

When you first find out Iris cysts in your dogs, consult an optometrist or general ophthalmologist.

In the early stages of diagnosis, detailed documentation (written and photo documentation) is vital to monitor progression by opthalmalaogist or by a specialist vet over time.

Always safely keep the digital information such as photographs, OCT, and UBM.

• Whole, unprocessed, or minimally foods (meats, seafood, grains, legumes, nuts, etc)
• Low-carb dog food (sweet potatoes, peas, yams, squash, pumpkin)
• Lean meat protein
• Shrimp, salmon, tuna, cod, halibut, trout, herring fish
• Blueberries, Kale, broccoli, carrots
• Oysters and pork.
• Leafy green vegetables (lettuce, spinach, salad greens, parsley, collard greens )

As most cysts for affected dogs are incidental and benign, they do not require treatment or monitoring over time. The Prognosis is also excellent. Some cysts are large, numerous or causing intraocular hypertension or blocking the pupillary margin, they are warranted for long-term monitoring for changes to vision every 3-6 months.