I have telangiectasia after rhinoplasty. Am I at risk if external incision is made in under eye surgery?

These are pretty common after nose surgery, and can be treated with laser.  Would be rare to see this occur in the lower lid after a bleph.  Also very rare to see any significant scarring after lower lid surgery.  Some people may get a hypertrophic scar out laterally beyond the canthus which can be treated with laser or steroid injections.  

Just because you have telangiectasias ion one area does not put you at risk with surgery to have them in other areas.

 Telangiectasias are much more common in the nose than they are in the eyelids. They can be treated with electrocautery, IPL, or laser.