The four vital factors about glaucoma are: IOP, visual field, optic disk C/D ratio and angle or depth of the anterior chamber.

I think the IOP is the most important factor effecting the glaucoma process and prognosis. Maybe you would not be agree with me.
In fact, we are incapable of diagnosing early onset of glaucoma. Because we could not judge which is the most vital contributed factor to glaucoma.

But blood pressure effect the IOP. The relationship between blood pressure and intraocular pressure are:

Blood Pressure

C/D ratio
mmHg 0.3 0.5 0.7 0.9
100- 20 16 12 8
120- 22 19 15 11
140- 25 22 18 14
160- 28 25 21 17

CAUTION: So if you have hypertension and high IOP, immediately go to your physician and take medicine.