Tim Connolly had a goal and assist, and Jochen Hecht, Patrick Kaleta, and Jason Pominville also scored for the Sabres (4-0-1). Myers and MacArthur also had assists.
Matt Moulson had a goal and assist, No. 1 draft pick John Tavares added a goal, and Andy Sutton also scored for the Islanders (0-2-3).
Islanders goalie Dwayne Roloson allowed four goals on 12 shots before being pulled in favor of Martin Biron in the second period. Biron finished with 20 saves.
Miller came in having surrendered just five goals in four games, and was particularly sharp in the final two periods when the Islanders peppered him with 30 shots.
Miller was shaken up with nine minutes left in regulation after a flurry in front of the Buffalo net, but was able to remain in the game.
Pominville scored his 100th career NHL goal with just over four minutes left to cap the scoring.
Connolly increased Buffalo's lead to 3-0 on a power play with his second of the season before Moulson made it 3-1 with 12:52 left in the second.
Hecht gave Buffalo a 4-1 lead — and chased Roloson in the process — when his slap shot from the top of the left circle went between Roloson's legs at 9:22 of the second.
Tavares made it 4-2 with his third of the season with 7:06 to go in the middle frame, capitalizing on Miller's gaffe behind the net. Miller was unable to corral a shootaround, allowing Tavares to sneak to the side of the net with the puck before depositing it in.
Myers, Buffalo's first-round pick in 2008, put the Sabres up 1-0 just 2:27 into the game when he backhanded a loose puck in the high slot past Roloson.
MacArthur was awarded a penalty shot with 5:38 left in the first period after he was hauled down by New York defenseman Mark Streit. MacArthur faked a wrist shot before slipping a backhander past Roloson.
The Sabres played their first game without Thomas Vanek, the high-scoring forward who sustained an upper-body injury Tuesday night against Detroit. Vanek was originally thought to be lost for at least a couple of weeks, but coach Lindy Ruff said Wednesday that Vanek could play in one of Buffalo's weekend games.
The Sabres host Atlanta on Saturday.
Notes
The two teams will meet two more times over the next 19 days. … Roloson, who played for the Sabres from 1998-2000, is 0-5-1 with one tie against Buffalo … Tavares' uncle, John, the National League Lacrosse's career scoring leader for the Buffalo Bandits, was in attendance. The younger Tavares was once a ball boy for the Bandits. … It was the second consecutive game that the Sabres have been involved in a penalty shot situation, and second straight game in which they knocked a goalie out early. … Daniel Paille replaced Vanek in the lineup.