If I follow correctly, you want to get the OCR'd text from each page of a document in a repository and read the text into a string.  If so, here is a bare-bones code snippet that will open a repository, retrieve a reference to a document, and read the text of each page into a List(Of String) object.

        Dim pageText As List(Of String) = New List(Of String)
        Dim raSession As Session = New Session

        'Open the session and login...
        raSession.Connect(New RepositoryRegistration("SAMANTHA-PC", "LFMAIN"))
        raSession.LogIn("admin", "admin")

        'Get a reference to the Document...
        Dim docInfo As DocumentInfo = Document.GetDocumentInfo(96960, raSession)

        'Instantiate a new PageInfoReader...
        Dim pageReader As PageInfoReader = docInfo.GetPageInfos

        'Step through each page of the document and read the text into the list...
        For Each pInfo As PageInfo In pageReader
            Using reader As StreamReader = pInfo.ReadTextPagePart
                pageText.Add(reader.ReadLine)
            End Using
        Next

        'Cleanup...
        pageReader.Close()
        docInfo.Dispose()
        raSession.Close()

Note:  You could even omit instantiating the DocumentInfo object if you don't need it in the routine and instead instantiate the PageInfoReader like this;

        'Instantiate a new PageInfoReader...
        Dim pageReader As PageInfoReader = Document.GetDocumentInfo(96960, raSession).GetPageInfos

But some might say that it is a little harder to follow what is happening...