providing {HEAD ~ an effective amount} of a photosensitive agent to {TAIL ~ the vessels} and thereafter activating said agent in said vessels with a low energy light sufficient to damage said vessels, and 
to
providing { HEAD ~ an effective amount } of a photosensitive agent to { TAIL ~ the vessels } and thereafter activating said agent in said vessels with a low energy light sufficient to damage said vessels , and
OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH