Question from David Keown
My 9 year old GSD has a black disk like cataract in one eye. Can it be removed safely and what’s the prognosis for a good recovery. Would this be expensive to remove? Is this usually done by my vet or a specialist eye vet? Thanks.

Answer from Shanika Williams MRCVS online vet

Hi David, thank you for your question about the black disc in your GSD’s eye (German shepherd dog).

What is a Cataract

Firstly I will describe what a cataract is; I do not think that your dog has a cataract but an iris cyst.

A cataract is an area of discolouration in the lens of the eye, the lens sits in the middle of the eye and is usually colourless and clear, it sits just behind the iris (coloured part of the eye). Usually a cataract can only be seen without the use of specialist equipment if it is very large or the lens has dropped out of its correct position and has fallen into the front chamber of the eye.

So what is the black disc?


The black disc that you are describing in your GSD’s eye is most likely to be an iris cyst. Iris cysts are fluid-filled black discs of varying size that bud off from another part of the eye. They vary in size (usually few millimetres in diameter) and can move around or are fixed in position; they are usually found at the front bottom half of the eye. I have personal experience of this condition, as our family German shepherd had several mobile iris cysts.

Does my pet need any treatment?

Iris cysts rarely cause a problem to your pet; they are not painful and rarely have any impact of your pet’s vision so we tend not to treat them. It is however important to distinguish an iris cyst from an iris melanoma (benign cancerous growth). Iris melanoma is a condition where there is a slow growing area of black visible within the front chamber of your pet’s eye.

Iris melanoma can lead to cataracts, glaucoma (increased pressure in your pet’s eye) and pain. If iris melanoma is suspected then it might be advised that your pet’s eye is removed. Most pets cope incredibly well after the removal of an eye. It is considered to be better not to have an eye than to have one that is diseased and causing a lot of pain.

So I would advise that your dog is examined by your own vet and then if required a veterinary ophthalmologist (eye specialist), if it is an iris cyst then your pets prognosis is excellent. If however iris melanoma is suspected then after the correct treatment which may involve eye removal then again the prognosis is good. I hope that this answer has helped you and your dog.

Shanika Winters MRCVS (online vet)

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