Allows Sublime Text to treat variables that start with $ as words. This file should named PHP.sublime-settings and should be located in your Packages/User directory next to your user preferences file.

PHP.sublime-settings

// this file should named PHP.sublime-settings
//  and should be located in your Packages/User directory (next to your user preferences file)
{
    // Characters that are considered to separate words
    //  this is modified from the default with the $ removed
    //  this allows PHP variables to be treated as words
    "word_separators": "./\\()\"'-:,.;<>~!@#%^&*|+=[]{}`~?"
}

Hi and thank you to share this.

I found one problem that makes me not use it : When all is selected, Sublime does not highlight other variable occurrence in the code.

Any idea how to fix that ?

@Cog-g install WordHighlight plugin. https://github.com/SublimeText/WordHighlight