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As optometrists, how many of them do we pay much attention to? As a profession, we are sceptical and hesitant to recommend treatment to our patients, let alone undergo it ourselves. But we have good reason - there is much conflicting information, press coverage and legal opinion, not to mention the occasional over-hyped enthusiasm for the latest technology.
Can we trust what the clinics tell us? Surely they only want to rob us of our precious patients? What really is the truth about modern refractive surgery?
This is my story
My aim in this article is, first, to explain how I decided to have laser treatment (even though this took more than six years of working within the field) and, second, it is to describe the excellent level of surgeon expertise and clinical care that contributes to a successful outcome.
As a young child of just five years, I was prescribed myopic spectacles. As I grew the myopia predictably increased, and with so many prescription changes I was restricted to the NHS frame range only. At 13-years-old my optometrist suggested RGP contact lenses 'to slow the progression of my myopia', which had reached approximately -6.00D mean spherical equivalent R&L.
Adjusting to the lenses was not easy but I was single-minded in getting rid of my ghastly specs with their uncoated CR39 lenses. I recall finding the contacts a breakthrough - at least for my confidence - although they often popped out at the most inopportune times.
For almost 20 years I persisted with the lenses, relatively happily however, corneal warpage had set in. When I wished to switch back to spectacles - having rediscovered how attractive they can be - my tolerance was limited.
Additionally, I had become an active outdoor person, and had begun to find lenses inconvenient.
I qualified as an optometrist in 1998 and seven years ago I started to work in refractive surgery. This field appealed to me as a new and interesting challenge, and I very much enjoyed it, despite my initial scepticism. Our university education in refractive surgery had been limited and unfortunately somewhat dated, so I was pleased to discover early on that things were different in the 'real world'.
Real world view
During the last few years I have observed the following: First, the technology has improved considerably and, second, I have come to understand that results are surgeon-dependent. In addition, I have seen dramatic improvements in procedure and safety measures, the introduction of wavefront technology, and have learned there is a considerable variation among available lasers.
I have recognised that tried and tested techniques have their place and 'the latest kit' is not necessarily the best. Wavefront technology, for example, has its place in working to reduce spherical aberrations (helping to prevent night vision difficulties in particular) but is not necessarily the key to 'superacuity'.
For the past year, I have had the privilege of working in a leading clinic and at around the time I started to work here my tolerance to RGP lenses had started to diminish.
I began to consider refractive surgery as an option. At the end of January 2006, I binned my rigid lenses and moved to soft torics, knowing that I would have to leave them out for some considerable time, due to long-term warpage risks. Now this was where the fun began.
My refraction on removing my lenses is shown in Table 1. Predictably, this started to change, and I found it difficult to keep up with contact lens changes, which were almost daily at first. Spectacles were out of the question, and I have first-hand experience of how difficult it is for long-term RGP wearers to adapt.
After almost six months the refraction had settled to considerable proportions (Table 2). We investigated these changes thoroughly using Orbscan and Atlas topography, ultrasound pachymetry, and WASCA wavefront assessment in order to rule out keratoconus indications.
Topographies were stable, there was no corneal thinning present, and on wavefront assessment such indicators as excessive coma were not present. And, despite the cylinder increase, the axes remained stable and horizontal. The conclusive factor, however, and that which ultimately gave me confidence in the procedure was undergoing Artemis 3D ultrasound corneal and anterior chamber scanning.
This unique equipment measures corneal thickness to 1 micron precision, thus giving true readings not found with any other technology. It also allows for detailed analysis of each of the corneal layers, and has demonstrated that, in keratoconus, epithelial changes are a significant indicator (epithelial thinning being present over the area of the cone, meaning that anterior changes are often initially masked).
Further preoperative information is shown in Table 3 and Figures 1 to 3.
As the Rx was now, to give myopia in the highest meridian, -9.00D R and -9.50D L, we planned to perform the treatment as a two-stage Lasik procedure. For high myopes this gives a more accurate and safe outcome, allowing adhesion to adequate safety margins for residual stromal bed postoperatively (the minimum RST should be 250µm). This is because the biomechanical healing response of the cornea can be more adequately controlled. My treatment was planned using a zero compression head Hansatome microkeratome and an 8.5mm diameter flap to facilitate the thinnest possible flap. Flap thickness can then be accurately measured using Artemis after the first stage of treatment.
The treatment plan was as in Table 4, using the Carl Zeiss MEL 80 Laser, with high myopic profile. The Mel 80 uses a Gaussian beam profile with a 0.7mm spot size at a frequency of 250Hz. These factors ensure a constant beam profile, as well as a short ablation time.
Despite having managed patients pre- and postoperatively for some time, this did not stop me feeling nervous before the surgery, and it was strange to be in the position of the patient.
However, my clinical colleagues put me at ease, and the surgery itself was far easier than I had imagined. Being constantly assured of what was going on around me helped considerably, although I think I received a little more technical information than the average patient.
Immediately before the surgery I took a few moments to look around without glasses and appreciate the full impact of my myopic error, knowing that this would be the last time I would see - or more correctly, not see - in this manner. Fifteen minutes later, after a technically perfect procedure, I was asked to sit up from the laser bed and open my eyes. I was overwhelmed to find that I could read the clock on the far side of the treatment room, albeit a slight milky view (due to natural oedema of the Lasik flap).
I was then asked to keep my eyes closed as much as possible for the next three hours, and when I opened them again I found that already the milky effect was diminishing. I fell asleep that night feeling assured and relaxed.
The following morning I opened my eyes, and for the first time for as long as I could remember I could see clearly. I now know exactly what those patient testimonials had meant - I had completely underestimated the impact that effect would have on me. Elated, I made my way to the clinic where at one day postoperatively we found the data presented in Table 5.
The most significant thing to note here is the BCVA, Both eyes have gained a line. This is a true sign of a successful procedure. The UCVA was remarkable, but would be expected to fluctuate over the next few weeks as the oedema and dryness vary.
At day one an Artemis was also performed to get an idea of the flap thickness, which had been made as thinly as possible in order to preserve residual tissue. These measurements were found to be 100µm R and 90µm L, and although at day one these were not completely accurate due to the oedema, they nonetheless indicated a safe procedure had been carried out.
Postoperative care is imperative, and my eyes were assessed at regular intervals. All patients are followed closely for the first year, and encouraged to return for regular annual examinations thereafter.
I am now at five months post-op and almost at the conclusion of my story. Over this time I have been able to appreciate some of the benefits of this treatment.
My morning runs have been transformed, I am swimming for the first time with good vision, and I am rock climbing without getting grit under an RGP lens.
I realise I am beginning to sound like one of those testimonials myself. During the first month or so I experienced the normal healing pattern of visual fluctuation and occasional dryness, although both of these have virtually diminished and, at the time of writing, are not concerning. I also noticed mild night glare during this time, but again this has now diminished. I have always had occasional haloes, and from time to time notice these still.
My refraction is now as shown in Table 6. This is still better than the aimed outcome - corneal biomechanics being largely responsible, and we will soon make a decision as to the second-stage treatment.
As a result of this, I can provide the following safe and honest information with which to advise patients considering refractive surgery:
? Research the surgeon: I cannot emphasise this point enough. An expert surgeon should be able to give accurate safety and outcome statistics for his/her individual treatments. An expert surgeon is also equipped with the skills to manage complications
? The technology: This can be a minefield for the patient, but correct application of good technology, backed by research is also important. If the clinic is actively involved in research and peer reviewed publications this is a very good indicator
? Patient management: Both pre- (in terms of managing expectations, as well as thorough clinical assessment) and postoperatively this is of paramount importance. Does the clinic accurately monitor all of its patients in detail? Again research publications give some idea of this.
If you are considering co-management of patients in practice ensure the clinic is also keeping a close eye on those patients. They should return to that clinic for periodic assessments, as certain tests will also need to be carried out there, and the ultimate responsibility lies with the surgeon.
Finally, do I have long-term safety concerns? With the careful assessment and planning I have experienced, not at all. Has the procedure changed my life for the better? It certainly has.
? Emma Firmager is an optometrist at the London Vision Clinic and vice-president of the British Society For Refractive Surgery