If have pterygium, can you do lasik?

Depends: Depends on how big the pterygium is.

Possibly: The pterygium needs to be small enough so that it does not interfer with the proper placement of the suction ring that is applied during the creation of the lasik flap. The pterygium also needs to be quiet and non-progressive. An alternative is prk or advanced surface ablation.

Depends: The primary issue here is that the pterygium is the complicating factor. If the ptrygium is small and doesn't cause much irritation, then it can be left, otherwise remove it before lasik. The next issue is how much astigmatism does it induce... That might be a reason to remove it specially if it is progressive/growing. Lasik can be done with nasal flap hing the goes under the ptrygium head.