What is different about combining ophthalmic practices to other...

What is different about combining ophthalmic practices to other medical practices like what PRY and HSP are doing, particularly medical centres, diagnostic imaging and skin care centres? It seems to be generally accepted that they have viable business models.

There must be some economies of scale for VGH in terms of equipment, administration and the having a number of consulting practices feeding the surgeries. However this would be most applicable to larger cities only. Do you have any input on this Redfaces?

Does anybody have any insights into whether VGH is actually able to increase the profitablity of the practices it buys so it can pay doctors the same while making a profit for investors?

VGH needing to increase what they pay their doctors is obviously going to decrease profits but VGH is fairly profitable at the moment. So does VGH have room to increase pay to doctors and still turn a profit?

Can anyone work out how much it is going to cost to increase pay enough to retain doctors. Any answers with this will help finding what VGH is worth.