how can I protect the sight she has left?

My dog (5 year old shih tzu) was diagnosed yesterday with glaucoma. She has already lost some vision, but we think she has partial vision left, at least in one eye, from her reactions. What can we do to protect this sight she has left and keep her eyes healthy and pain free?

You need to discuss that with the veterinary opthomologist who diagnosed her.

Glaucoma can be either traumatic (as a result of injury to the eye) or genetic. If it's in both eyes, it's likely genetic in the case of your dog. Glaucoma can't be cured, but it can be managed. Eye drops prescribed by a vet to reduce pressure in the eyes should help to reduce any discomfort and slow the progression. There are also surgical procedures that can help substantially. If this were my dog, I would be asking for a referral to a canine opthamologist (eye specialist). They can evaluate the severity and present you with all possible options for treatment. It certainly can substantially decrease her quality of life, but it is not a death sentence and should not shorten her life if appropriately managed. There is additional information about the condition and possible treatment options here: http://www.blinddogs.com/articles/glaucoma.htm

You need to talk to your vet about treatment. He may have to refer you to a veterinary ophthalmologist for specialized surgery or treatment.