The answer to your question is not so straight forward, but glaucoma diagnosis is not clear cut.
Let me give you a brief back on glaucoma.
Glaucoma is a condition where the optic nerve which sends the signals back to your brain slowly degrades.
This optic nerve degradation happens to everyone. It becomes glaucoma when the nerve thinner happens faster and you are risk of losing vision.
This nerve degeneration happens very slowly.
So, age and life expectancy has to be taken into account.
If you were 100 years old, you probably won't need treatment because though the nerve is thin, it won't poop out on you.
At 74, your doctor has to make a guess whether the nerve will last you another good 10-20 years.
So, it would be good to get a second opinion because you have to take into account how thin your nerves are, your age, family history, and eye pressures.
Your glaucoma did not just appear over night. There were signs of it even a year ago during your exam in clearwater. Your doctor may have thought your nerves were only moderately thin.
I think the difference at the most recent visit was the the pressure of 27, which is elevated.
High eye pressure alone doesn't mean you have glaucoma, but just one of the risk factors.
So, I don't think you should be overly concern.
Continue to take the Xalatan as prescribed if it is not bothering you too much and you can get a second opinion with your previous ophthalmologist.
Let me know if you have any questions or something I can clarify for you.
What else could cause high eye pressure.
There are various other causes such as inflammation or blockage of the drainage channels in your eyes. Sometimes, straining can cause a brief elevation in pressure.
27 is not terribly high. It is more important to look at the trends -- whether it is high on most of your visits.
In most people, there is no good reason identified.