1. Combine egg white and water; stir well, and set aside. Combine cornmeal and next 3 ingredients. Dredge fillets in flour; dip in egg white mixture, and dredge in cornmeal mixture.
2. Coat a large nonstick skillet with cooking spray, and place over medium-high heat until hot. Add fillets, and cook 3 minutes on each side or until fish flakes easily when tested with a fork. Transfer to a serving platter; garnish with lemon wedges, if desired.