How do you decide whether or not to excise a pterygium prior to cataract surgery?  

The indications to remove the pterygium prior to cataract surgery: Symptoms in terms of irritation and itchiness. You don't want patient rubbing their eye after cataract surgery, or patients not satisfied with the pain persisting following cataract surgery Pterygium close or covering of the visu...

If the patient is symptomatic (irritation, redness) or has significant astigmatism affecting keratometry measurements.

I'll remove a pterygium prior to cataract surgery if I suspect the pterygium will need removal at some point in the future. This could mean: 1.) I have seen evidence of pterygium progression in the recent past (either physical growth onto the cornea as compared to historical measurements/photos, or...

If you're going to excise it, always do so prior, as it will change the IOL calculations. Give the patient the best results.