A total of 31 of the 62 patients who had cataracts removed earlier this month experienced blurred vision and swollen corneas – normally one in 400 have such side effects, according to Musgrove.
Patients, who were treated under local anaesthetic in a mobile unit beside the day surgery unit, have been recalled and given treatment to ease the problem, but some may need further surgery in the future.
Health chiefs, who are braced for possible compensation claims, are unsure what caused the reaction to the procedure to remove cataracts and replace them with lenses and an investigation is underway.
Musgrove’s medical director Dr Colin Close said private firm Vanguard Healthcare was taken on on May 2 to reduce a backlog of cataract patients caused by an influx of emergency patients in the winter of 2012/13 and difficulty replacing medical ophthalmology staff who had left.
He stressed the lengthy waiting list was not due do NHS cutbacks, while Musgrove is currently advertising for an ophthalmology consultant.
Vanguard’s £320,000 contract for 400 operations was terminated after four days after over 30 of the 62 patients operated on complained, more than ten of them with “significant” issues.
“We still don’t know exactly what the cause is – we’re trying to identify that at the moment. There could be a range of causes,” said Dr Close.
“You would normally expect one in 400 patients to experience these complications – here we had a trickle of patients coming through complaining of blurred vision, which wasn’t expected.
“There’s a possibility a small number might need surgery in the future – where these patients are identified, we will follow them up long-term to provide care and treatment as required.”
Musgrove is hopeful most of the patients will recover completely after follow-up visits.
Dr Close said Musgrove could possibly be hit by a wave of compensation claims.
He added: “Any financial responsibility would rest with us.
“If any patients wish to pursue compensation, we would work with them."
The Vanguard mobile unit used for the operations has been quarantined while an investigation seeks to discover whether the fault was down to human error or mechanical or chemical reasons.
“At the moment we don’t have that answer,” said Dr Close.
“We’re deeply disappointed for our patients, but we want to reassure everybody in Taunton that they can have complete confidence in our own ophthalmology department.
“Anyone coming up for cataract surgery in Musgrove has nothing to be worried about.”
In a statement issued to the County Gazette headed ‘We don’t always get things right, but we are committed to learn’, Musgrove chief executive Jo Cubbon said: “Some of our patients, many of whom had already waited longer than they should have, will now have to wait again for their operation.
“We are very sorry this has happened and are working to put a solution in place so that these patients will receive their treatment as soon as possible.”
Phil Hicks, spokesman for Vanguard, whose website claims the company has “the world’s largest fleet of mobile healthcare facilities”, said they were asked by the trust to help them solve a problem clearing a backlog of cataract patients.
He added: "We are cooperating fully with them to assist with investigating the likely cause(s) of the higher rate of known complications than expected.
"We have with the hospital conveyed to the patients our concern and sympathy for the discomfort or distress they have experienced.
"These procedures were carried out in Vanguard’s operating theatre, using highly qualified surgeons with many years’ experience of working in the NHS and who were vetted by the trust. Vanguards core business is the provision of clinically equivalent operating theatre facilities, and no other services of the kind deployed in this case are currently in operation."
A spokesman for Somerset Sight said: “Experiencing sight loss can be stressful and worrying.
“It is extremely concerning to us that people are being put through the added stress of surgical complications at an already difficult time.
“Cataracts are one of few eye conditions that can be treated and it is our concern that people will lose confidence in what is supposed to be a safe and effective procedure.”
“But where capacity is a problem and there is a need for outside people to be brought in, the important thing is quality, particularly with people’s health.”
*Anyone with further concerns can contact Musgrove’s Patient Advice and Liaison on 01823-343536.
*Somerset Sight, which has a team of volunteers offering information and support at Musgrove’s eye clinic, can be contacted on 01823-333818.