In a large bowl, combine chopped salmon, panko breadcrumbs, egg, mayonnaise, Dijon mustard, parsley, green onions, garlic powder, paprika, salt, and pepper. Mix until well combined.
Shape the mixture into 4 even patties. Place them on a baking sheet and refrigerate for 15-30 minutes to help firm up.
Meanwhile, prepare the avocado salsa by combining diced avocado, tomato, red onion, cilantro, lime juice, salt, and pepper in a small bowl. Gently mix to combine.
Preheat the grill to medium-high heat and lightly oil the grates to prevent sticking. Grill the salmon patties for about 4-5 minutes per side, or until fully cooked.
While grilling, toast the buns for 1-2 minutes until golden brown (optional).
To assemble, place lettuce on the bottom half of each bun, followed by the grilled salmon patty. Top with a generous scoop of avocado salsa, and cover with the remaining bun.
Serve immediately with your favorite side dishes.