Junior doctors at University Hospital Southampton blew the whistle amid concern that patients with serious eye conditions were not being given follow-up appointments amid staff shortages.
An investigation has so far identified 38 patients who have suffered a worsening of their condition due to the situation.
At least 7,000 patients suffering from conditions like glaucoma were not given appointments, as the trust failed to cope with rising demand, Health Service Journal reports.
Trainee doctors wrote to managers at the trust earlier this year, warning of their concerns at the risks to patients.
The Royal College of Ophthalmologists said similar problems were likely to be occuring elsewhere, amid a national shortage of consultants.
By January, the backlog had reached 7,000 patients, including 4,500 with glaucoma and 2,500 with diabetes-related eye problems.
Around 3,000 glaucoma patients are still to be notified and reviewed, with “significant progress” made among diabetes patients, the trust said.
Both conditions are among the leading causes of blindness.
The trust said it would bring in extra staff, locum doctors and send some patients to other trusts.
“All patients have been risk assessed to ensure those at increased risk are being seen sooner,” the spokesman said.
Michael Burdon, president of the Royal College of Ophthalmologists, said he believed similar problems were occuring in most NHS trusts treating the eye conditions.
Research by the college suggests 230 new ophthalmology consultants are needed to deal with the rising demand.
Mr Burdon said: “There’s a mismatch between capacity and demand across ophthalmology in the NHS.
“More patients are being put on waiting lists that don’t tend to end up being managed appropriately, and we get a situation where there are hundreds if not thousands of patients on the lists.”