Wasn't given drops until damage was found just months later, can it happen that fast?

In the beginning of this year my optometrist referred me to the eye hospital because I had high eye pressures of 28-33.

They did about 6 tests on me including visual field test and took pictures of my optic nerve. Everything was fine at this point. But they said they didn't know the cause of my high pressure so they said come back in 5 months.

Well I came back in the beginning of July and they found early nerve damage in both eyes :(

I am now on Latanoprost drops for the rest of my life to control the IOP and further damage.

The drops are responding well, dropping my pressures to a good range, but I am wondering why they did not give me the drops back in January? Did I really miss my last chance in 5 months to not catch the first damage?

It feels like they waited for me to get damage before treating it instead of dropping my pressures to prevent it.