Hi ES Barnes
You can read about the light touch review on page 135 of the Guide to PIP claims and Reviews. They won't be expecting your to send in new evidence - they will just get you to say whether there have been any changes in your condition (in your case it is worse). Hopefully, they will decide you need the same level of support - but that will only be known when you get the decision letter.
BIS
Nothing on this board constitutes legal advice - always consult a professional about specific problems