A pensioner from Gloucestershire says the NHS postcode lottery means he could go blind within two months.

Ray Stuart, 71, from Tewkesbury, has age-related macular degeneration and his friends have been forced to rally round to find money to pay for drugs the NHS is not supplying.

Three vital injections of the drug Avastin could save his sight – but it is not available on the NHS in Gloucestershire.

UK cancer experts yesterday accused a health watchdog of forcing patients to remortgage their homes to afford treatments freely available in Europe. A group of 26 professors were "dismayed" at guidance issued by the National Institute for Health and Clinical Excellence (Nice) to deny patients four kidney cancer drugs, including Avastin, on the NHS.

They said the decision showed it was time for a "radical change" in how the NHS makes decisions on what treatments are available for cancer sufferers.

"It is essential that Nice gets its sums right," they said in a letter to a Sunday newspaper. "We have already seen distraught patients remortgaging their houses, giving up pensions and selling cars simply to buy drugs that are freely available to those using health services in countries of comparable wealth."

The professors said the NHS spent less than two-thirds of the European average on cancer drugs. Mr Stuart has particular reason to be infuriated as the drug he needs is available to patients in some neighbouring counties. But because he lives in Tewkesbury, he has to pay for the drug.

Now, at a cost of £2,000, his golfing buddies have come to his aid to get the treatment privately. Thanks to his friends at Puckrup Hall Golf Club he has been able to afford the first of the £650-a-time injections. He hopes to have the second in September and the third in October.

He said: "Having worked all my life, I had hoped I may be able to get something back from what I had put in. How sad that I have to rely on the generosity of other people.

"Eyesight is something you take for granted. Then suddenly you realise you could be without it. It's upsetting."

He added that the drug itself costs £25, but additional costs bumped up the total bill.

Gloucestershire Primary Care Trust said it did not offer Avastin on the NHS, but did provide an altered version of it, Lucentis, to people with particularly serious AMD. In a statement, it said it was awaiting national guidance on the drug's effectiveness. A spokesman added: "We always consider carefully any application from a patient's doctor to fund a drug's use in individual cases where it is believed there may be exceptional circumstances. A patient has the right of appeal."

Mr Stuart is grateful to his golfing friends, who raised £616 for him at an open day.

Nice chief executive Andrew Dillon said in response to the professors' claims yesterday: "The group of distinguished oncologists writing in today's Sunday paper are wrong to suggest that Nice poorly assesses cancer treatments."

"We have made it possible for thousands of cancer patients to receive treatment when, without our guidance, they would almost certainly have not. It therefore cannot be the case ... that our methods for valuing new treatments are unsuitable for cancer drugs.

"The provisional conclusions on the use of drugs for treating renal cancer are those of an independent Appraisal Committee whose membership is largely drawn from NHS clinicians in active practice.

"They understand the issues at stake. They themselves are often involved with the care of patients with cancer, but they are also involved in the day-to-day care of patients with other conditions, many as distressing for those who live with them as cancer (such as – to name but a few – motor neurone disease, heart failure and primary progressive multiple sclerosis)."

He said that for the oncologists to "maintain the credibility of their argument" they need to explain which patients with other diseases "should forgo cost effective care in order to meet the needs of those with renal cancer".