What's the difference between glaucoma and ocular hypertension?

Subset. Ocular hypertensives are a subset of "glaucoma." this is because they fall into the category of glaucoma suspects. Not all ocular hypertensives go on to develop glaucoma (actually a small overall percentage in the ocular hypertension treatment study), and others have glaucoma without elevated eye pressures. Glaucoma suspects need to be followed to see if they develop glaucoma.
Risk vs. damage . Glaucoma is actual damage to the optic nerve. Ocular hypertension is elevated intraocular pressure and is simply a risk factor for developing glaucoma. Risk can be calculated based on guidelines provided by the nih ocular hypertension treatment trial.
Nerve Damage. Glaucoma is diagnosed when nerve damage is present. Ocular hypertension describes an elevated pressure with no nerve damage. Studies have shown that the incidence of glaucoma transition in ocular hypertenives to glaucoma is less if the elevated pressure is treated. Discuss your options with your ophthalmologist.