List Comments with #tag in Comment Content

Hi, I’m in the middle of adding support for tagging comments in WordPress. I’ve currently got a working version, but it’s not optimized. The current approach fetches all the comments and display the ones matching the tag. For example, a comment with #tag will display on the /tag/ page. Has anyone created a custom query to fetch _only_ the comments matching the tag? Here’s the unoptimized code I’ve got so far:

<?php
	$comments = get_comments();
	foreach ($comments as $comment) {

		if (preg_match('/#'.$tag.'\b/i', $comment->comment_content)){
			echo "<h3>Comments tagged \"#$tag\"</h3>";
			break;
    	}
    }	

	?>

  	<ol class="commentlist">

	<?php
	$comments = get_comments();
	foreach ($comments as $comment) : ?>

	<?php
		if (!preg_match('/#'.$tag.'\b/i', $comment->comment_content)){
		//display comments with our hash tag only
    		continue;
    	}
	?>

Thanks!