Small clear globe or sac in Dog eye

Question
I have a 7 year old, English Mastiff named Bailey.  Just recently I have noticed a small, clear "globe" of sorts in her right eye.  It moves around freely inside of the eye, between the cornea and the surface of the eye.  It is approximately 1/8" in diameter and is somewhat brown or dark on the edges, although you can see through it.  She has no history of eye problems in this eye although she does have entropion in here left eye with a discharge which has been present for several years and began discharging ~4 months ago.

I have spent an enormous amount of time looking for information on the internet but have not found any symptoms of eye problems that present in this manner.

Do you have any ideas?

Thank you for your time,
John K. Northey
Bonner, Montana

Answer
John,

What you are describing may be an iris cyst.  Although, typically those look like small brown floating bubbles, and are not usually clear.  There are also incidences of the lens of the eye luxating and ending up in the anterior chamber.  That would look like a large clear floating bubble.

I recommend you have you dog checked out by a veterinary opthalmologist.  Both iridial cysts and luxating lenses can cause damage to the eye by either being a cause of inflammation, called uveitis, or they can block drainage channels in the eye and cause glaucoma.  I do know that some dogs with iridial cysts can have them with no apparent complications, but it's better to be safe than sorry.

You can ask your regular veterinarian for a referral.  Or if your regular veterinarian has the equipment to measure eye pressures, they might be able to help you diagnose and determine if further treatment is warranted.