Indemnity, implants and instrumentation

Refractive surgery has suffered from a certain amount of bad press over the past year. Both clinics and independent surgeons have noticed that prospective patients are more wary and some centres have seen a drop in the number of patients seeking surgical correction of their refractive error.
The skills and experience of the surgeon are undoubtedly key factors in the outcome of refractive surgery and there are many good surgeons in the UK. However, there is nothing to stop surgeons who have very little experience and training from performing refractive procedures. Unlike countries such as the US and Canada, refractive surgery training in this country has not been formalised. Unfortunately, the Royal College of Ophthalmologists is not likely to act on this matter and has only produced guidelines for surgeons, which are to be published shortly. Formal training and accreditation may be introduced in the near future following the call by Frank Cook MP for the Government, the British Medical Association and the RCO to bring in such measures. His early day motion has now gathered enough signatures from fellow MPs to require a working party to be set up.
Much of the recent bad press surrounds the rise in medico-legal claims associated with refractive surgery. Christopher Liu, consultant ophthalmic surgeon at Sussex Eye Hospital, Brighton, and council member of the BSRS, gathered together a summary of ophthalmic claims from the Medical Protection Society (MPS) and the Medical Defence Union (MDU) for an excellent presentation at this year's BSRS conference back in May.
In a five-year period between February 1998 and January 2003, 22.6 per cent of all disclosed ophthalmic legal cases (28 out of 115) were related to refractive surgery. In answer to why this percentage should be quite so high, Liu pointed out that the rise in the number of refractive treatments to around 60,000 per year was undoubtedly a factor, but there are more important reasons. The MDU lists unrealistic expectations and the failure to gain proper informed consent as key reasons in many of the cases it has dealt with.
Since the majority of MDU members do not undertake refractive procedures, the MDU has recently decided to shift the cost of the growing legal claims on to refractive surgeons, rather than sharing it between the membership. This has resulted in an increase in indemnity premiums up to an incredible £18,000 per annum for some full-time refractive surgeons, and some surgeons who have had claims made against them, whether proven or rejected, have been refused cover.
This has profound implications for refractive surgery in the UK, as it is likely to deter highly skilled corneal consultants who feel it is no longer worthwhile insuring themselves to perform low-volume refractive surgery. Some would argue that those who dabble in refractive surgery are likely to have a higher complication rate than those who spend the majority of their working week performing refractive procedures, but the relationship between volume and results is far from simple. High volume can mean more pressure on time and less experience of treating serious corneal complications such as microbial keratitis. On the other hand, high volume can mean a lower complication rate related to a perfected surgical technique.
Individual surgeons must shoulder some of the blame for claims resulting from unrealistic expectations, but the 'refractive surgery industry' as a whole is implicated to a greater extent.
The advertising in the media presents a strong message to potential patients that refractive surgery is a simple, risk-free procedure. As a result, patients often do not listen when surgeons talk about complications, assuming that it won't happen to them. It should also be remembered that even those of us with a scientific background struggle at the best of times to interpret statistics and measures of risk. Stating risk in terms of a percentage is insufficient for many patients.
Inadequate informed consent is also a common problem. It is not enough for the patient to simply sign each paragraph of the consent form relating to the risk of a particular complication occurring. The MDU requires proof that the surgeon has talked through each section individually before it is signed, requiring at least 45 minutes with the surgeon. All treatment options must be discussed fairly, even if the choice to opt for a particular type of surgery requires referring the patient to another surgeon with expertise in that area, as when a phakic intraocular lens is deemed more suitable than Lasik.
With regard to the involvement of optometrists in co-management, the MDU specifies that the surgeon should only delegate tasks to competent individuals who have undergone training and by this they mean more than one short course.
The complications that can occur post-refractive surgery, whether acute or chronic, require specialist knowledge that is not covered by basic optometric training.
The Association of Optometrists states that optometrists should only enter into co-management of a patient with a surgeon, if they are confident that they can provide the necessary clinical service to a high standard and that the patient is aware of any fee the optometrist may receive from the surgeon. It is also up to the individual optometrist to ensure they are confident in the skills of the surgeon they are working with.
It would be highly unsuitable for bodies such as the BSRS to produce a list of recommended surgeons Ð how would individuals be judged as suitable for a start? Optometrists need to investigate for themselves in their own area by visiting clinics, talking to surgeons about their own personal success rates and complication rates and talking to others in the field.

Using the Orbscan
The traditional keratometer found in the majority of optometric practices may be adequate for fitting the majority of contact lenses, but when it comes to more complex corneas, a topography unit can be very useful.
Such instruments, whether based on a Placido disc (eg TMS and Eyesys), or scanning slit design, are expensive and rarely found in optometric practice. For those involved with refractive surgery patients, however, it could be argued that the ability to assess fully the curvature of the cornea, both before and after surgery, is essential.
Traditional keratometry is wholly inadequate for such a task as it makes inaccurate assumptions about the shape of the postoperative cornea. The Orbtek Orbscan is a particularly sophisticated form of topographer that uses light scatter to image 20 slits of the cornea and creates a corneal map detailing the anterior and posterior curvature, corneal thickness and anterior chamber depth. The Orbscan II combines slit-scanning with a Placido disc unit. Its level of sophistication has led many users to believe that it must always be accurate, even when it does not agree with data from another instrument.
Professor Charles McGhee from Auckland, New Zealand, spoke at this year's conference about the benefits and limitations of the Orbscan system. Anterior elevation maps have been shown to be very accurate centrally (1.4µm) but less so in the periphery.1 A number of authors have reported mid-peripheral steepening following corneal refractive surgery, suggesting strange biomechanical changes in the cornea. McGhee, however, was able to show that this steepening is in fact an artefact by measuring an ablated PMMA lens Ð this material cannot bow after ablation but the Orbscan measurements still suggest that it has. This is due to poor imaging of rapid change in curvature at the edge of the optical zone. The reproducibility of the Orbscan measurements for anterior elevation was found to be excellent at 0.1±0.3µm for a single observer, and 0.4±0.4µm between observers for a PMMA test object.
The use of the Orbscan to assess corneal thickness is rather more questionable. The Orbscan produces corneal thickness measurements that are 4-10 per cent thicker than either optical or ultrasound methods for normal eyes,2 but the difference is repeatable over time. Chakrabarti3 showed that this problem is exacerbated after refractive surgery with overestimation of thicker corneas and underestimation of thinner corneas. McGhee pointed out that Orbscan pachymetry measurements are very informative, particularly in relation to highlighting areas of localised thinning, but are not good for making critical decisions, such as whether there is sufficient corneal thickness to consider a retreatment.
Orbscan is one of the few instruments that can provide information about the shape of the posterior cornea. Localised posterior elevation may indicate early signs of keratoconus preoperatively, or surgically induced keratectasia. A correlation between the quantity of posterior steepening and the degree of myopia treated has been reported4 but the same paper also pointed out the discrepancy between the Orbscan and ultrasonic pachymetry measurements, suggesting errors in the imaging of the posterior corneal surface. Stromal haze is certainly known to influence Orbscan measurements but, to date, no one has been able to confirm or refute the accuracy of posterior elevation map.

References
1 Cairns G, McGhee CNJ, Collins MJ, Owens H, Gamble GD. Accuracy of Orbscan II slit-scanning elevation topography. Journal of Cataract and Refractive Surgery, 2002; 28,12:2181-2187.
2 Marsich MM, Bullimore MA. The repeatability of corneal thickness measures. Cornea, 2000; 19;6:792-795.
3 Chakrabarti HS, Craig JP, Brahma A, Malik TY, and McGhee CJ. Comparison of corneal thickness measurements using ultrasound and Orbscan slit-scanning topography in normal and post-Lasik eyes. Journal of Cataract and Refractive Surgery, 2001; 27:1823-1828.
4 Naroo SA, Charman WN. Changes in posterior corneal curvature after photorefractive keratectomy. Journal of Cataract and Refractive Surgery, 2000; 26:872-878.
The recently published 'Information for patients' can be found on the Royal College of Ophthalmologists' website at www.rcophth.ac.uk. Details of the Early Day Motion put forward by Frank Cook MP can be found at www.edm.ais.co.uk

Dr Catharine Chisholm is a research fellow at the Applied Vision Research Centre, City University, LondonRefractive surgery has suffered from a certain amount of bad press over the past year. Both clinics and independent surgeons have noticed that prospective patients are more wary and some centres have seen a drop in the number of patients seeking surgical correction of their refractive error.
The skills and experience of the surgeon are undoubtedly key factors in the outcome of refractive surgery and there are many good surgeons in the UK. However, there is nothing to stop surgeons who have very little experience and training from performing refractive procedures. Unlike countries such as the US and Canada, refractive surgery training in this country has not been formalised. Unfortunately, the Royal College of Ophthalmologists is not likely to act on this matter and has only produced guidelines for surgeons, which are to be published shortly. Formal training and accreditation may be introduced in the near future following the call by Frank Cook MP for the Government, the British Medical Association and the RCO to bring in such measures. His early day motion has now gathered enough signatures from fellow MPs to require a working party to be set up.
Much of the recent bad press surrounds the rise in medico-legal claims associated with refractive surgery. Christopher Liu, consultant ophthalmic surgeon at Sussex Eye Hospital, Brighton, and council member of the BSRS, gathered together a summary of ophthalmic claims from the Medical Protection Society (MPS) and the Medical Defence Union (MDU) for an excellent presentation at this year's BSRS conference back in May.
In a five-year period between February 1998 and January 2003, 22.6 per cent of all disclosed ophthalmic legal cases (28 out of 115) were related to refractive surgery. In answer to why this percentage should be quite so high, Liu pointed out that the rise in the number of refractive treatments to around 60,000 per year was undoubtedly a factor, but there are more important reasons. The MDU lists unrealistic expectations and the failure to gain proper informed consent as key reasons in many of the cases it has dealt with.
Since the majority of MDU members do not undertake refractive procedures, the MDU has recently decided to shift the cost of the growing legal claims on to refractive surgeons, rather than sharing it between the membership. This has resulted in an increase in indemnity premiums up to an incredible £18,000 per annum for some full-time refractive surgeons, and some surgeons who have had claims made against them, whether proven or rejected, have been refused cover.
This has profound implications for refractive surgery in the UK, as it is likely to deter highly skilled corneal consultants who feel it is no longer worthwhile insuring themselves to perform low-volume refractive surgery. Some would argue that those who dabble in refractive surgery are likely to have a higher complication rate than those who spend the majority of their working week performing refractive procedures, but the relationship between volume and results is far from simple. High volume can mean more pressure on time and less experience of treating serious corneal complications such as microbial keratitis. On the other hand, high volume can mean a lower complication rate related to a perfected surgical technique.
Individual surgeons must shoulder some of the blame for claims resulting from unrealistic expectations, but the 'refractive surgery industry' as a whole is implicated to a greater extent.
The advertising in the media presents a strong message to potential patients that refractive surgery is a simple, risk-free procedure. As a result, patients often do not listen when surgeons talk about complications, assuming that it won't happen to them. It should also be remembered that even those of us with a scientific background struggle at the best of times to interpret statistics and measures of risk. Stating risk in terms of a percentage is insufficient for many patients.
Inadequate informed consent is also a common problem. It is not enough for the patient to simply sign each paragraph of the consent form relating to the risk of a particular complication occurring. The MDU requires proof that the surgeon has talked through each section individually before it is signed, requiring at least 45 minutes with the surgeon. All treatment options must be discussed fairly, even if the choice to opt for a particular type of surgery requires referring the patient to another surgeon with expertise in that area, as when a phakic intraocular lens is deemed more suitable than Lasik.
With regard to the involvement of optometrists in co-management, the MDU specifies that the surgeon should only delegate tasks to competent individuals who have undergone training and by this they mean more than one short course.
The complications that can occur post-refractive surgery, whether acute or chronic, require specialist knowledge that is not covered by basic optometric training.
The Association of Optometrists states that optometrists should only enter into co-management of a patient with a surgeon, if they are confident that they can provide the necessary clinical service to a high standard and that the patient is aware of any fee the optometrist may receive from the surgeon. It is also up to the individual optometrist to ensure they are confident in the skills of the surgeon they are working with.
It would be highly unsuitable for bodies such as the BSRS to produce a list of recommended surgeons Ð how would individuals be judged as suitable for a start? Optometrists need to investigate for themselves in their own area by visiting clinics, talking to surgeons about their own personal success rates and complication rates and talking to others in the field.

Using the Orbscan
The traditional keratometer found in the majority of optometric practices may be adequate for fitting the majority of contact lenses, but when it comes to more complex corneas, a topography unit can be very useful.
Such instruments, whether based on a Placido disc (eg TMS and Eyesys), or scanning slit design, are expensive and rarely found in optometric practice. For those involved with refractive surgery patients, however, it could be argued that the ability to assess fully the curvature of the cornea, both before and after surgery, is essential.
Traditional keratometry is wholly inadequate for such a task as it makes inaccurate assumptions about the shape of the postoperative cornea. The Orbtek Orbscan is a particularly sophisticated form of topographer that uses light scatter to image 20 slits of the cornea and creates a corneal map detailing the anterior and posterior curvature, corneal thickness and anterior chamber depth. The Orbscan II combines slit-scanning with a Placido disc unit. Its level of sophistication has led many users to believe that it must always be accurate, even when it does not agree with data from another instrument.
Professor Charles McGhee from Auckland, New Zealand, spoke at this year's conference about the benefits and limitations of the Orbscan system. Anterior elevation maps have been shown to be very accurate centrally (1.4µm) but less so in the periphery.1 A number of authors have reported mid-peripheral steepening following corneal refractive surgery, suggesting strange biomechanical changes in the cornea. McGhee, however, was able to show that this steepening is in fact an artefact by measuring an ablated PMMA lens Ð this material cannot bow after ablation but the Orbscan measurements still suggest that it has. This is due to poor imaging of rapid change in curvature at the edge of the optical zone. The reproducibility of the Orbscan measurements for anterior elevation was found to be excellent at 0.1±0.3µm for a single observer, and 0.4±0.4µm between observers for a PMMA test object.
The use of the Orbscan to assess corneal thickness is rather more questionable. The Orbscan produces corneal thickness measurements that are 4-10 per cent thicker than either optical or ultrasound methods for normal eyes,2 but the difference is repeatable over time. Chakrabarti3 showed that this problem is exacerbated after refractive surgery with overestimation of thicker corneas and underestimation of thinner corneas. McGhee pointed out that Orbscan pachymetry measurements are very informative, particularly in relation to highlighting areas of localised thinning, but are not good for making critical decisions, such as whether there is sufficient corneal thickness to consider a retreatment.
Orbscan is one of the few instruments that can provide information about the shape of the posterior cornea. Localised posterior elevation may indicate early signs of keratoconus preoperatively, or surgically induced keratectasia. A correlation between the quantity of posterior steepening and the degree of myopia treated has been reported4 but the same paper also pointed out the discrepancy between the Orbscan and ultrasonic pachymetry measurements, suggesting errors in the imaging of the posterior corneal surface. Stromal haze is certainly known to influence Orbscan measurements but, to date, no one has been able to confirm or refute the accuracy of posterior elevation map.

References
1 Cairns G, McGhee CNJ, Collins MJ, Owens H, Gamble GD. Accuracy of Orbscan II slit-scanning elevation topography. Journal of Cataract and Refractive Surgery, 2002; 28,12:2181-2187.
2 Marsich MM, Bullimore MA. The repeatability of corneal thickness measures. Cornea, 2000; 19;6:792-795.
3 Chakrabarti HS, Craig JP, Brahma A, Malik TY, and McGhee CJ. Comparison of corneal thickness measurements using ultrasound and Orbscan slit-scanning topography in normal and post-Lasik eyes. Journal of Cataract and Refractive Surgery, 2001; 27:1823-1828.
4 Naroo SA, Charman WN. Changes in posterior corneal curvature after photorefractive keratectomy. Journal of Cataract and Refractive Surgery, 2000; 26:872-878.
The recently published 'Information for patients' can be found on the Royal College of Ophthalmologists' website at www.rcophth.ac.uk. Details of the Early Day Motion put forward by Frank Cook MP can be found at www.edm.ais.co.uk

Dr Catharine Chisholm is a research fellow at the Applied Vision Research Centre, City University, London