Tuna patties can be dry. If you find some spice combination you really like (you know how much spice and salt you prefer), try it out with some egg whites (you can buy them in a carton) and some panko (or other bread crumbs). Taste the combination with the tuna. Then put everything in the blender and chop them briefly so they 'ball up' in the blender with the egg white binding the mixture. Spray them with Pam or brush with some olive oil and bake in a really hot oven (or under the broiler) until brown and crusty. Just experiment and you will find something you like!
(Possible additions: grated or shredded vegetables - onions, carrots, zucchini, pepper, even some drained tomato!)