Trials of a drug for age-related macular degeneration (AMD) have produced extremely promising results in almost all recipients.
The condition, which is diagnosed in around 24,000 patients each year, causes blindness in ten per cent of sufferers by the abnormal formation of blood vessels leading to fluid leakage.
However, patients treated with Lucentis, a drug developed by Genentech, found that the gradual deterioration of their sight was halted and many patients even regained their vision.
More than a third of participants with the most damaging form of the disease, 'wet' AMD, had their sight damage reversed and additional vision loss was prevented in almost all patients.
One 75-year-old British recipient of the drug told the Times that 80 per cent of his life had been taken away by the condition, but that Lucentis had enabled him to take up golf again.
"Within three days my sight had improved," he revealed. "It cost me nearly £5,000, but I'm very pleased."
The drug has not yet been recommended for use on the NHS and costs £1,000 per treatment but the exciting results of the trials will lead many patients to seek private treatment.
The Royal National Institute of the Blind's head of campaigns, Steve Winyard, told the Times that the results showed the drug to be "just as good as we thought it was going to be".
"About 30 per cent of these patients got a significant gain in sight, which shows that the drug also offers improvements as well as preventing sight loss," he said.