Why age filter doesn't filter the age using sql query in laravel?

I want to query list of persons based on age. Then, the query will calculate the age using lahir_yy column(birth year value) and search for the list.

   $newitem = DB::table('itemregistrations')
                ->when(request('age'), function($query){
                    $query->whereRaw('YEAR(CURDATE()) - lahir_yy >= ?', [request('age')]);
   ->get(); 

However, the code doesn't work. It doesn't filter the age but giving no error.

via Chebli Mohamed