Macro Delete Duplicate Rows with Exception

I am creating a macro to delete rows based on a duplicate value in column E (see code below). However, there are times that I signify a blank cell with "--", in these instances I would like to not delete those rows because there is other information that is needed. Thanks for your help in advance.

Private Sub RemoveDuplicateRowsSR()

Dim rCell As Range
    Dim rRange As Range
    Dim lCount As Long
     
    Set rRange = Range("E8", Range("E" & Rows.Count).End(xlUp))
    lCount = rRange.Rows.Count
     
    For lCount = lCount To 1 Step -1
        With rRange.Cells(lCount, 1)
            If WorksheetFunction.CountIf(rRange, .Value) > 1 Then
                .EntireRow.Delete
            End If
        End With
    Next lCount

End Sub