Widespread delays in follow-up times for patients with wet age-related macular degeneration are resulting in unnecessary and irreversible vision loss, an investigation has shown.

A Freedom of Information request by the Macular Society found two thirds of the 80 NHS trusts who gave details did not meet the four-week threshold for the eye condition.

It said many of those failing to comply with the NICE guidelines blamed ‘a lack of resources to cope with the sheer numbers of patients requiring treatment’.

Helen Jackman, chief executive of the Macular Society, said: ‘It is unacceptable that two thirds of NHS trusts are failing patients in this way. Many will have inevitably experienced unnecessary and irreversible sight loss due to the delays in introducing new treatments and follow-up times.

‘We are constantly hearing about how busy eye clinics are across the country. However, a third of trusts are able to treat their patients within NICE guidelines, showing it is not an impossible task.’

It was also found that some trusts were not providing funding for NICE-approved treatments, including 26 per cent for diabetic macular oedema and 34 per cent when it came to retinal vein occlusion.

A major study published in The Lancet last week showed macular degeneration accounted for 7 per cent of global blindness in 2010, up from 5 per cent 20 years earlier. Blindness due to cataract, meanwhile, had fallen from 39 per cent to 33 per cent of cases between 1990 and 2010, but was still the leading cause of blindness.

Researchers leading the study at The Anglia Ruskin University also found blindness caused by macular degeneration was higher in regions with older, higher-income populations, such as Europe and North America. In those areas more than 15 per cent of blindness was caused by macular degeneration, compared to 2.6 per cent in south Asia and 4.6 per cent in Oceania.