People facing the prospect of going blind may have their sight saved by the use of a drug now available on the NHS.

West Sussex Primary Care Trust (PCT) has decided to pay for the cost of the drug Avastin to treat wet age related macular degeneration (AMD).

More than 30 patients across the county have already been chosen to begin treatment which can help slow the progress of the disease, the biggest cause of blindness in Britain.

Avastin is widely used privately to treat AMD but it is not generally available on the NHS, where it is only licensed for the treatment of bowel cancer.

However, some PCTs across the country have decided to go ahead with using Avastin to treat AMD because it is believed to be as effective as other treatments, such as Lucentis, but is significantly cheaper.

Lucentis is being assessed by the National Institute for Health and Clinical Excellence (Nice) and a decision on whether to make it freely available on the NHS is expected this summer.

Currently, PCTs can prescribe the drug to patients who fit the right criteria but its use is restricted because it is expensive.

But because Avastin is cheaper, more patients will now be treated.

A report to the West Sussex PCT board showed the cost of providing Avastin would be about £1.4 million during the first year, compared to £4.7 million for Lucentis. Director of public health Farhang Tahzib, who wrote the report, said the move to provide Avastin was backed by senior surgeons in the county.

Mary Hopwood, 71, from Langley Green, Crawley, has been paying privately for Avastin to treat her AMD.

She said: "When I had AMD diagnosed I assumed I would get the drug automatically on the NHS. But then they said they wouldn't pay for it.

"Luckily I have family who could afford to pay privately but there are others who are not so lucky. It is good to hear the PCT has decided to fund the drug. Hopefully more people will now receive treatment."

Peter Hayward, West Sussex PCT consultant in public health, said: "The PCT wants to ensure people in West Sussex who have AMD are offered more treatment options on the NHS than are currently available.

"While waiting for definitive guidance from Nice on the use of Lucentis, the drug Avastin has been approved by the PCT board, which means more people in West Sussex will be treated for the condition."

Moorfields Eye Hospital in London, one of the world's leading centres for eye health, is among the hospitals using the drug.