Regex to ignore accents? PHP

Question

Is there anyway to make a Regex that ignores accents?

For example:

preg_replace("/$word/i", "<b>$word</b>", $str);

The "i" in the regex is to ignore case sensitive, but is there anyway to match, for example
java with Jávã?

I did try to make a copy of the $str, change the content to a no accent string and find the index of all the occurrences. But the index of the 2 strings seems to be different, even though it's just with no accents.

(I did a research, but all I could found is how to remove accents from a string)