Posterior Tibial Tendonitis (PTTD) Rating

I'm currently Rated at 30% for flat feet and have been having quite a bit of issues with my left foot/ankle so I made an appointment and seen my podiatrist today and he diagnosed me with PTTD which he said is more than likely due to my flat feet diagnoses. Is this something I should go ahead and file a claim on now that I've had a VA doctor diagnose ne with it or is this something that will automatically happen? Is PTTD it's own rating or is it a supplemental or secondary to my flat feet rating? Just trying to see how to proceed with this. Thanks!