My wife is developing Glaucoma and wants to know if inversion poses are potentially detrimental to her when she does yoga?

Interesting question as I know some positions are not usually recommended for individuals with blood pressure concerns and that will sometimes include those with glaucoma.
Here is one thought on the topic... it appears there may be some benefit when done slowly and depending on the particular circumstances. I'd have your wife check with her eye doctor and her teacher as well to see if they have any information.

Yoga Journal - Yoga Asana Columns - A Closer Look at Inversions (http://www.yogajournal.com/practice/246)