Can I still have lasik surgery if I have glaucoma?

Yes in most cases. Lasik will not interfere with your glaucoma treatment in most cases. However, if you have low-tension glaucoma, advanced damage from glaucoma, or if you have had glaucoma filtering surgery, a variation of lasik called surface ablation (lasek, prk) may be a safer alternative.
Depends. If your glaucoma is mild and controlled, then you can consider laser vision correction. If your glaucoma is more advanced or uncontrolled, then laser would be inappropriate.
Possibly. Possible depends on level, and you understand the possible side effects. In lasik, pressure on the eye of a compromised optic nerve must be considered. However, this pressure is very short in duration. Consider prk which does not apply any significant pressure to the eye. Also, nearsightedness laser treatments change the central corneal thickness, can alter your pressure reading at check ups.
LASIK and glaucoma. One step in the lasik procedure involves suction on the eye. This raises the pressure in the eye to a fairly high level for a short time. For people with glaucoma, this may affect the health of the eye. Although we do not know the long-term effects of lasik on glaucoma patients, glaucoma is a relative contra-indication for lasik. Prk may be an option.