Is it true that you're supposed to clean out your freezer once in awhile?

i went in there the other day to get a vintage hungry man turkey dinner that i bought back in '97, and much to my surprise, the entire freezer compartment was a block of ice. i think that my dinner is still in there though, but it's hard to tell through the greenish tint and all of the frozen roaches. what do you say...should i thaw that bad boy out and nuke it?