We know very little about Eisen's career.
TCSNA, Class of 2634. He was a "plank owner" onboard the Victory (CV-40) - he spent the entire thirty-five year war onboard the ship, starting with an assignment as Communications Officer. We know he fought as part of the Venice Offensive in 2643, but other than that his Academy friend Raul Dominguez was also there, there isn't anything known about that portion of history.
He was highly decorated during the war, and fought the Victory for ten years beyond her planned operational lifetime. His involvement in the Kilrah operation lead to some celebrity after the war, and he ended up writing the Academy textbook on carrier operations. With the Victory retired after the war, he was given command of the newly refitted TCS Lexington (CV-44)... and the rest is Wing Commander 4.