By Nick Triggle
Health reporter, BBC News
The phrase postcode lottery has become a cliche when talking about the NHS.
The availability of drugs in the NHS is a complex issue
Outraged campaigners can be found filling newspaper column inches and TV and radio airtime criticising the availability of drugs in one area and not another.
But buried beneath the headlines is a much more complex picture - and nowhere is that more apparent than in the case of the sight-saving drug Lucentis which treats wet age-related macular degeneration, the leading cause of blindness in the UK.
The injections can make a real difference. A two-year course stabilises a person's condition and can even restore some sight in some cases.
However, the treatment comes at a price - £10,000 for each eye to be precise.
The cost initially prompted the National Institute for Health and Clinical Excellence (NICE), the body which assesses drugs for the NHS, to say it should only be used when someone has gone blind in one eye.
This, of course, provoked outrage and NICE eventually relented.
But perversely that decision now means a treatment that a significant number of doctors had been using to fight the condition at a fraction of the cost of Lucentis may have to be dropped.
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We need an organisation like NICE to sort out the most cost effective treatments
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This is despite eye specialists which are using Avastin, more commonly known as a bowel cancer drug, believing it can be as effective at treating AMD as Lucentis.
With NICE approving Lucentis, health bosses may feel duty bound to tell doctors they can only use the more expensive drug.
It is an issue which has exercised Derbyshire Primary Care Trust in particular.
The trust is responsible for funding local services and as such is concerned about the finances.
It told NICE ahead of its decision on Tuesday that it should give consideration to Avastin as it could save the health service money.
It pointed out that it is being used in such a way in Italy and the US as well as by eye specialists in the UK in their private practice.
But the problem is that NICE cannot recommend Avastin for wet AMD treatment because it can only consider drugs for their licensed purpose.
And the company which developed Avastin, US firm Genentech, also produced Lucentis.
Suffice to say, it is not in Genentech's interests to spend money on getting a licence for Avastin to treat wet AMD.
Roche, the drug firm which is marketing Avastin in Europe for Genentech, says neither firm is planning to push forward for a licence for wet AMD.
A spokeswoman said 10 years were spent developing Lucentis for the market and it was best to focus on Avastin's use in the battle against cancer.
"Avastin has brought clinically meaningful benefits in three major cancers, and Roche therefore remains committed to its further development in the treatment of cancer."
Nor has a strong campaign been forthcoming from campaigners such as the Royal National Institute for the Blind (RNIB).
The RNIB, like many charities, are partly reliant on drug firms for donations. One of their donors is Novartis, the firm responsible for marketing Lucentis for Genentech in the UK.
No-one is suggesting RNIB has been influenced - and indeed the charity points out Novartis' donation is responsible for less than 0.3% of its income and trials have yet to prove the effectiveness of Avastin - but the relationship demonstrates that there is much more to the story than the headlines suggest.
The Macular Disease Society, which says it receives no funding from pharmaceutical companies, has also not campaigned for Avastin's use as a treatment for wet AMD.
It says this is because there is, as yet, no accepted research on its effectiveness or the risks associated with its use.
NICE chairman Sir Michael Rawlins is already on record questioning the relationship between patient groups and drug firms.
In particular, he has suggested they should do more to quiz firms about the cost of drugs.
Patient groups have not been shy to have their say, claiming it takes too long for NICE to recommend treatment.
Lucentis alone took two years to work its way through the system - and in the meantime NICE was not even able to recommend a cheaper alternative.
And in the end it illustrates the dilemma the NHS faces.
Michael Lavin, an eye surgeon from Manchester Royal Eye Hospital, has been using Avastin to treat wet AMD since 2005.
He says as a doctor he is happy to use either, describing their effectiveness as "probably equivalent".
But he adds: "As a tax-payer, I want to know why the NHS is going to spend 30 to 50 times as much on a drug when there is a cheaper alternative."
Unfortunately, there is not a simple answer.