What is the chance of getting glaucoma when having a port wine stain by the eye?

Glaucoma is an eye disease that is sometimes ociated with port wine stain birthmarks. I have a port wine stain birthmark right next to my eye, which follows down to my lower eye lid. And I am soon enough getting it surgically removed off. I will have to have a glaucoma test thought and would like to know the chances of having this eye disease. thanks guysss :)