I have a question i.e. how can I possibly extract meta data of a Visualforce page inside a Page Layout of an object.

For fetching the page layout I use following API request : 

    https://ap4.salesforce.com/services/data/v43.0/sobjects/Account/describe/layouts

but using this if there is a visualforce page inside a particular page layout, it only shows that a visualforce page has been added, but it doesn't gives what input fields has been there in that particular VF page.

How can I get meta data of a VF page.

Here is where I am insering my VF page : 
[![VF page inside Page layout][1]][1]

TIA


  [1]: https://i.sstatic.net/su7pd.png