Extract comments from pdf using Acrobat SDK (Interop.Acrobat.dll) using VB. NET

Question

I am using the Acrobat SDK to extract text from pdf files.

This works quite well.

My code does not extract the text from comments though.

Is it possible to extract the text from comments/annotations using the Acrobat SDK?

I know I can use iTextSharp and it works well, but I only want to use a single library.

Code below:

Public Shared Function AdobePdfParse(strFileName As String, strTxtFromFile As String) As String
    'Note: A Reference to the Adobe Library must be set in Tools|References!
    'Note! This only works with Acrobat Pro installed on your PC, will not work with Reader
    Dim AcroApp As CAcroApp, AcroAVDoc As CAcroAVDoc, AcroPDDoc As CAcroPDDoc
    Dim AcroHiliteList As CAcroHiliteList, AcroTextSelect As CAcroPDTextSelect
    Dim PageNumber, PageContent, i, j, iNumPages
    Dim strResult As String

    AcroApp = CreateObject("AcroExch.App")
    AcroAVDoc = CreateObject("AcroExch.AVDoc")
    If AcroAVDoc.Open(strFileName, vbNull) <> True Then Exit Function

    AcroPDDoc = AcroAVDoc.GetPDDoc
    iNumPages = AcroPDDoc.GetNumPages

    Dim intfirst As Integer = 1

    For i = 0 To iNumPages - 1
        PageNumber = AcroPDDoc.AcquirePage(i)
        PageContent = CreateObject("AcroExch.HiliteList")
        If PageContent.Add(0, 9000) <> True Then Exit Function
        AcroTextSelect = PageNumber.CreatePageHilite(PageContent)
        ' The next line is needed to avoid errors with protected PDFs that can't be read
        On Error Resume Next
        For j = 0 To AcroTextSelect.GetNumText - 1
            strTxtFromFile = strTxtFromFile & AcroTextSelect.GetText(j)
        Next (j)
    Next i

    AcroAVDoc.Close(bNoSave:=0)
    AcroApp = Nothing
    AcroAVDoc = Nothing

    'Return sbTxtFromFile
    Return strTxtFromFile

End Function