Fence Slow in VBA microstation v8i

Actually I'm working with the fence , by this way :

Set oCircle = CreateEllipseElement2(Nothing, startPointLoop, radius, radius, oMatrix, msdFillModeNotFilled)
With ActiveSettings
.FenceVoid = False
.FenceClip = False
.FenceOverlap = True
End With
Set oFence = ActiveDesignFile.Fence
oFence.DefineFromElement View1, oCircle
Dim oFenceContents As ElementEnumerator
Set oFenceContents = oFence.GetContents
Do While oFenceContents.MoveNext

' Here we work with any element of the fence

loop

Thanks in advanced for your help !!!