Elderly patients may be losing their sight because some health trusts are refusing to fund a specific drug, a BBC investigation has revealed.
"Wet" AMD affects 26,000 people a year, says the RNIB
BBC South's Inside Out programme has found that some primary care trusts are refusing to let consultants prescribe a drug that can save people's vision.
Trials have shown the licensed drug Lucentis is effective in treating "wet" age-related macular degeneration (AMD).
But some trusts are still waiting for clinical guidance before funding it.
That guidance from the National Institute for Health and Clinical Excellence (Nice) is not due until September.
But the government says it is unacceptable for the trusts to refuse treatment simply because the guidance does not yet exist.
What is AMD?
The macula is the part of the eye used for seeing straight ahead
It allows people to see fine detail and colour
AMD occurs when the delicate cells of the macula become damaged
"Wet" AMD accounts for about 10% of AMD cases
It results in blood vessels growing behind the retina, causing bleeding and scarring
It develops quickly but can respond to treatment in the early stages
In Reading, Bournemouth, Poole and Oxford the drug's use is not funded at all, while in Southampton, Portsmouth and Salisbury trusts say funding is only considered on a case-by-case basis.
That means consultants are not allowed to prescribe it without going through a referral process - despite the fact the condition can cause major sight loss in as little as three weeks.
A report published by the Royal National Institute for the Blind (RNIB) claims that 90% of all primary care trusts are refusing to pay for the drug, one of a class known as anti-angiogenics.
It prevents the formation of abnormal, new blood vessels in the eye, and dries up vessels which have already begun to leak.
The RNIB says that 26,000 people a year develop "wet" AMD and only 7,000 of those would benefit from photodynamic therapy, the existing alternative to Lucentis.
Steve Winyard, from the RNIB, said: "We're hearing from more and more people who have been told that they can benefit from the treatment but that their hospital is refusing to help them.
"So they are faced with that awful choice of having to raise cash, otherwise they will go blind."
Professor Andrew Lotery, a lead ophthalmologist based at Southampton General Hospital, said he was angry that some patients were being forced to pay for the treatment.
He said: "The National Health Service, as I understand it, should be free at the point of access and there shouldn't be a postcode lottery. So I'm very keen for these drugs to become available on the NHS as soon as possible."
Professor Lotery is calling for the use of Lucentis to be funded
A spokeswoman for the Berkshire West Primary Care Trust said it would be holding a meeting next week to look at funding the drug.
She said: "We have received a number of requests from consultant ophthalmologists for funding of the drug and, as Lucentis is now licensed, these requests will be looked at on a case by case basis following the meeting."
A spokeswoman for the Bournemouth and Poole Primary Care Trust also said its use of Lucentis would be reviewed to determine "its place locally in treatment".
A spokeswoman for Oxfordshire Primary Care Trust said: "Oxfordshire PCT currently funds photodynamic therapy for macular degeneration as recommended by Nice.
"We currently do not provide funding for the drug Lucentis. However, the Oxfordshire NHS Priorities Forum will be reviewing these treatments over the next few months."
A spokeswoman for the Department of Health said: "Patients should not be refused a treatment simply because Nice guidance does not exist yet."