Cross-posted from the Ferret Health List...
 
>....About a year ago I noticed (Sassy) was developing a small "dot" over
>her right eye.  I investigated and discovered she was developing cataracts.
>This was confirmed by her veterinarian.
>
>Her right eye at this point is completely covered and she has a small
>catarct on her left eye now.  She gets around well and I have made
>provisions for this disability.
>
>My question is regarding glaucoma.  Is it common in ferrets?  How can I
>and my veterinarian determine if she has glaucoma?  If I can have her
>tested what treatments or medications are available?  I do not want her
>to suffer with painful eye pressure, swelling, etc.
>
>Any information, recommedations, or website info would be GREATLY
>appreciated.  I'm aware of your incredible reputation and finese regarding
>ferrets, and your busy schedule.  I appreciate any information you may
>be able to provide me.
>
>Respectfully,
>Larry Rodriguez
 
Dear Larry:
 
Glaucoma is not a common ferret disease, but we occasionally see it.
Glaucoma is an increase in pressure in the eye due to lack of filtration
of the aqueous humor.  The eye normally produces this clear liquid which
fills the space between the front of the lens and the back of the cornea.
Normally, it drains out through what is known as the filtration angle.
When the filtration angle is malformed (so-called primary glaucoma) or is
blocked (so-called secondary glaucoma) the pressure in the eye increases,
resulting in pain and eventually atrophy of the inner workings of the eye
due to the constant elevated pressure.  Blindness may be a reult, as the
retina is very sensitive to pressure increases.
 
The risk of glaucoma is slightly increased in animals with cataracts.
Rarely a cataractous lens may shift forward in the eye, blocking the
filtration angle.  Additionally, in rare cases.  lens proteins from the
degenerating cataractous lens may result in an inflammation of the globe
(uveitis) which may proceed to secondary glaucoma.  These sequelae are
not common, but they can happen.
 
Glaucoma is treated most commonly with drugs which constrict the pupils,
which have the effect of opening the filtration angle.  Pilocarpine is
available in ointment form, and although I have little experience with
it in ferrets.  Truth be told - because blind ferrets are excellent at
masking their blindness, most ferrets with glaucoma are presented only
after irreversible damage to the eye is done.
 
For evaluation and treatment of glaucoma in a ferret, I would first
recommend a trip to an opthalmic specialist, if at all possible.  Accurate
measurement of ocular pressures in ferrets is very difficult due to the
small size of the eye, and someone with extensive expeience in taking
pressures would probably give the best evaluation.
 
With kindest regards,
Bruce Williams, DVM
[Posted in FML issue 3339]