使用编辑选项时，nl2br（）会创建一个额外的新行

I am using textarea to save content in mySQL DB and using nl2br to preserve line breaks used by user.

PHP method of using nl2br

$description = safe_var($_POST['description']);
$text = preg_replace('#[
]+#', "
", $description);
$description_html = nl2br($text);

Now, when i am using edit option of update the description then there is a new <br/> added everytime i press update button.

It means that if first time my content looks like as below

Line 1
-----one space
Line 2
----- One space
Line 3

And then if i update this content with some words then i get output like as below and this is not expected

Line 1
-----one space
-----one space
Line 2
----- One space
-----one space
Line 3
-----one space
Line 4

Is there any way to prevent new lines to already added spaces until unless user gives a space.