Noblemen needing laser treatment (5)
I believe the answer is:
earls
'noblemen' is the definition.
(earl is a kind of nobleman)
'laser treatment' is the wordplay.
'treatment' is an anagram indicator (letters treated or processed differently).
'laser' anagrammed gives 'EARLS'.
'needing' acts as a link.
(Other definitions for earls that I've seen before include "Noblemen (with a Court?)" , "London exhibition centre" , "Lear's out for the flight of the nobility" , "members of the House of Lords" , "Peers of the realm" .)