Eye-test stress
High-tech scanning linked to surge in referrals
Hospital eye services have been hit with an increased workload partly caused by new scanning technology at optometrists — including big chains such as Specsavers.
Imaging technology to check for potential problems like glaucoma is becoming widespread in optometry practices, which is funnelling more referrals into the public system.
Specsavers now uses the technology on all of its customers and says this, as part of a wider assessment, helps pick up otherwise undetected disease. The company says it will soon have New Zealand data, but in Australia more than 80 per cent of referrals are appropriate, leading to diagnosis and treatment.
But some ophthalmologists are wary of such widespread testing — including more than 400,000 scans at Specsavers a year — because potential problems can turn out to be nothing to worry about.
Such “incidentaloma” cause more workload in a health system already struggling to cope with an ageing
population and conditions such as diabetes. Several Kiwis permanently lost sight in recent years because of ballooning wait lists.
Optical coherence tomography (OCT) gives detailed information about the retina, which helps detect disease. Specsavers had the technology in all its 52 stores by last September, with more than 485,000 scans expected in the following year.
A ministry memo for Health Minister David Clark before a July 2018 meeting with the British-based company noted OCT was already available at many other optometrists.
“Specsavers Optometrists propose to scan all patients as part of the pretest screening routine, and expect this to detect an additional 100 cases of eye disease per week,” said the Health Ministry memo, released under the Official Information Act.
“There is concern that this will lead to an increase in patients being referred to DHBs for unexpected findings, or for interpretation of findings of uncertain clinical significance.”
The Royal Australian and NZ
College of Ophthalmologists (Ranzco) had said testing such as OCT wasn’t needed if a patient had no symptoms or a relevant medical history, the ministry noted. That position was developed for a wider “choosing wisely” campaign, led by health workers worried about unnecessary procedures and treatment.
Ranzco recommended members at DHBs audit referrals to see if Specsavers ones are appropriate.
After some DHBs told the ministry about an increased workload, it wrote to all health boards to ask about the issue. Auckland, Hawke’s Bay, and Taranaki DHBs all confirmed more referrals from optometrists.
Dr Peter Hadden, chair of the NZ branch of Ranzco, said the increase in demand couldn’t be definitively attributed, given no comprehensive audits or studies had been done. “But you would think [optometrists’ use of OCT] must have had something to do with it. They are picking up stuff that hasn’t been seen before, and some of it is important. On the other hand, they are picking up a lot of stuff that isn’t important.”
Whangarei-based ophthalmologist Dr Brian Kent-Smith, a past chair of Ranzco’s NZ branch, said his own opinion was indiscriminate use of any medical test was ill advised.
“Unnecessary tests will lead to unnecessary follow-up appointments, either at the DHB or in a private practice. Someone — the taxpayer, the individual or the insurance company — is going to pay for that.”
A spokesman for Specsavers said it had not been made aware of any concerns about its use of OCT, but would expect it to increase referrals to DHBs, particularly because about half of the 115,000 Kiwis estimated to have glaucoma remain undiagnosed.
“The OCT has beneficially brought into play technology’s ability to identify
They are picking up stuff that hasn’t been seen before, and some of it is important. On the other hand, they are picking up a lot of stuff that isn’t important. Dr Peter Hadden, Ranzco
possible signs of glaucoma that the naked eye and other equipment just can’t see.”
Every Specsavers patient has a pre-examination process including an OCT scan. Based on results and the patient’s history, the optometrist considers further tests and assessments.
“If the combination of the preexamination results, visual field and findings during the examination suggest a significant risk of glaucoma in line with . . . guidelines then, in discussion with the patient, a referral is made to an ophthalmologist. It does seem that some practitioners are under the false impression that Specsavers uses the OCT in isolation when this is just not the case.”
The spokesman said detailed NZ data would soon be available, but in Australia, 83 per cent of referrals are later confirmed to be appropriate, leading to diagnosis and treatment.
“Of course . . . should Ranzco NZ choose to refine their referral criteria then we will be the first to adopt the updated guidelines.”
An Auckland DHB spokeswoman said it continued to see very high growth in demand for ophthalmology services, with a 10 per cent increase in first surgical appointments and 14 per cent rise in follow-up appointments in the 2018/19 financial year.
A Health Ministry spokesman said it hadn’t been advised of DHBs having trouble dealing with volumes of referrals from Specsavers outlets.