Overriding Meta Page Description from a UserControl

Hi,
I wonder if someone can help me. In my CMS system (RetroViz.cms  I override my master page meta description and title data so that when viewing articles within my CMS, this information is relevant to the article presented.
I do this by creating a new MasterBase class for my master pages as below:
 
Public Class MasterBasePage
Inherits System.Web.UI.MasterPage

Private _pageTitle As String
Private _pageDescription As String

Public Property PageTitle() As String
Get
PageTitle = _pageTitle
End Get
Set(ByVal value As String)
...