to detect progressive conditions such as glaucoma
John Rose owns an independent practice in Kingston. He has always invested in technology (‘starting with a Humphrey VFA’ which he has since swapped for the HEP to ‘save on space’ and to better link with the OCT) and boasts an array of instruments, including even a microperimeter and a biometer. Around eight years ago, he introduced the Spectralis OCT but has kept its predecessor, the HRTII, which he still uses regularly.
Evolving practice
‘All private patients have multicolour OCT assessment. I long ago rejected the “quickie” approach to see if I could survive by doing a thorough and comprehensive examination, charged at an appropriate level. When the NHS was set up, average life expectancy was less than 65. This is now much higher and elderly clients tend to have more complex needs – the average 80-year-old has four to five medical problems and by 2035 over 65s will make up 23% of the population. As optometrists, we are the custodians of the eyes and are charged with looking after our client’s vision throughout life. Can we carry on doing this effectively with just a “guessing tube” and a puff of air?
‘With the increase in life expectancy – now is the time to embrace this and invest in technology and maybe then as a profession we can move away from the antiquated and restrictive model imposed on us by the GOS. We know that for the vast majority of chronic diseases, age is the single biggest risk factor. The NHS is beginning to realise this. Recently Simon Stevens, chief executive of NHS England said, “We’ve got to move away from health services that are predominantly reactive and waiting for something to go wrong.”
‘I think the best way of doing this is a form of accountancy for the eyes – taking careful repeatable measurements of the eye over time to measure changes. In order to do this successfully, we need to use available technology that can take accurate and repeatable measurements.’
OCT on everyone
‘I would argue that this should be undertaken on everyone, regardless of family history and age, as without a baseline measurement we are not able to demonstrate change. By establishing a baseline at an early age it is far easier to be able to detect change when it occurs, even if the client is still clinically “normal”.’
Case 1
‘AP was a 31-year-old contact lens patient I first saw in 1999. He was -5.00D R&L, had normal full threshold fields, IOPs of 16mmHg R&L, CD ratios of R 0.6 and L 0.5, and no family history of glaucoma. At a follow up three years later, the HRTII difference maps (1) highlight changes, especially in the right eye with tissue loss in the inferior temporal region of the disc. I referred this chap and the hospital agreed that there was glaucomatous changes and commenced treatment. Incidentally, at the time of referral, I didn’t possess a pachymeter but subsequently invested in one and discovered that he had corneas of around 500 microns that we now realise increases the risk for progression.’
Case 2
‘The Spectralis uses two beams of light – one to track movement which then acts as a reference to guide the second beam that performs the scans, thus minimising motion artefacts and ensuring point to point registration in real time without having to fix with software after capture. Knowing that your scans are repeatable gives you great confidence that any change you see is genuine.
Figure 2
‘Routine macular thickness scans (2) taken during a routine examination of a 47-year-old asymptomatic patient appointment all look pretty unremarkable. After four months, the patient was reseen as she felt “a vague sensation that her vision didn’t feel right”. There now appeared a change in the macular thickness scans (3). In fact, there appeared to be a subtle thinning of the retina at the fovea in the left eye and the software has picked up a difference in the symmetry between the eyes. Interestingly, there was also a subtle difference in the RNFL scans over that time with a slight thickening in the nasal sectors of right eye and temporal sectors of left eye. All other measurements were unremarkable.
Figure 3
‘Armed with this information, I referred her to a neuro-ophthalmologist and sent the scans as well. Typically, I did not receive a letter back from the hospital. However, she presented again recently for another exam and told me she had been diagnosed as having multiple sclerosis – and reported the scans provided had greatly aided a speedy diagnosis. This is ground-breaking stuff.’
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Part 2: Technology in community practice