Annual Meeting Review 2009 - Leeds
by Gary Finnegan in Leeds
President of UKISCRS, Tayo Akingbehin, welcomed members to the Leeds Armouries, noting that the 2009 Annual Meeting would cover an even wider range of topics than in the past. He said the attendance at meetings continues to grow and he expressed confidence that colleagues would take something from the programme which would enhance their clinical practice. The President extended a special welcome to guest speakers who had travelled from overseas to share their expertise with the Society.
Cynthia Roberts of Ohio State University kicked off the refractive programme with a detailed overview of the biomechanics of the cornea. She described how the layered structure of the cornea determines its shape and compared these layers to a series of rubber bands stacked on top of one another. “If you sever the lamellae and reduce the tension in the layers they will never again bear the same tension that they did preoperatively,” said Dr Roberts, a world-renowned expert in biomedical engineering.
As with all biomechanical properties, there is great variability from one patient to the next. This leads to a broad range in the changes to measured pressure in a patient population. Dr Roberts warned against relying on linear correction factors because the chance of getting it right is less than 1%.
Infection risk with laser surgery
Delivering a keynote speech on Lasik complications, Sheraz Daya provided a comprehensive look at infections arising from surgery. Infections remain among the worst complications a surgeon can face but it is possible to reduce the risk, he said. The increased volume of laser vision correction procedures saw an associated rise in infections a decade ago. However, evidence from a series of ASCRS studies indicates a significant improvement since then.
There has also been change in the source of infection over time. In 2001, mycobacterium was to blame for almost half of all infections, but in 2004 Staphylococcus aureus was the most common. It was replaced by MRSA in 2007. Mr Daya noted that health workers are particularly vulnerable to infections and this should be considered when such patients present for surgery. Early clinical identification and classification is important, said Mr Daya, adding that surgical intervention is advisable in Grade III and Grade IV infections. He recommended lifting the flap and irrigating in serious cases.
This was echoed by Sanjay Mantry who advocates lifting the flap and performing a corneal scrape at the earliest opportunity in order to give the patient the best chance of a swift recovery. He said health professionals should be screened prior to surgery due to the heightened risk they face.
Mark Wevill discussed when and how to treat epithelial growth, noting that major risk factors included abrasions, surgeon inexperience, epithelial injury and patient age of more than 40 years. There is a six-fold increased risk with intralase treatments, he added.
Paul Rosen gave a strong presentation on the diagnosis and management of diffuse lamellar keratitis (DLK) and central toxic keratopathy (CTK). DLK is very common in its milder form, with up to 10% of patients affected. Outlining its aetiology and pathogensis, he said urgent treatment can prevent progression to corneal melt. Prevention being better than cure, Mr Rosen stressed the value of meticulous preparation of instruments and surgical technique. CTK is a much rarer condition but a troublesome condition as it does not respond to steroids, he said.
Discussing femtosecond laser flap complications, Wayne Crewe-Brown warned against being blinded by the advantages of new innovations and outlined ways of combating some emerging problems. Opaque bubble layers (OBL) can interfere with the effectiveness of additional laser pulses and make flap lifting more difficult. Excessive OBL can also impeded some excimer laser tracking systems and distort ultrasound measurements taken during intraoperative pachymetry, he said. This problem can be addressed by adjusting pocket depth, width and line to optimise gas evacuation. He also outlined a range of postoperative events which can arise with femtosecond flaps and suggested mitigation strategies.
This was followed by informative talks by James Ball and Andy Morrell on Dry Eye Syndrome, before Jan Venter and Jonathan Moore looked at the risks and benefits of retreatments in a session entitled “to lift or not to lift”.
Opening a session on challenging clinical scenarios, Brian Little used the example of the Argentinian Flag Sign to illustrate the importance of clinical decision making. Complications do not arise due to a failure of a surgeon’s technical abilities but can be attributed to underdeveloped cognitive skills. He showed a video of how doing things in the wrong order and failing to adapt to an unforeseen situation resulted in an avoidable error. Cognitive skills training can produce better results, including a 50% reduction in vitreous loss rate. “Cognitive training works, it’s important and we can all do it. It just takes a little discipline,” he said.
Khiun Tjia discussed the value of using OZil technology for phaco “chops” in cataract surgery. He said it is essential to have low-flow settings and described the OZil as ideally suited for very dense cataracts. “It is challenging and difficult cases where OZil makes the biggest difference,” said Mr Tjia, who helped develop OZil technology.
Adrian Glasser from the University of Huston delivered the Pearce Medal Lecture in which he asked whether it is possible to restore accommodation in presbyopes. He offered a broadly encouraging conclusion but was blunt in his assessment of some of the intra-ocular lenses currently on the market, a number of which do not take account of the fundamental mechanisms underpinning accommodation.
Dr Glasser stressed that subjective measures are of limited value in assessing accommodation and urged colleagues to rely exclusively on objective techniques. He said the use of subjective measurements had given the erroneous impression that scleral expansion bands and some types of IOL can reverse presbyopia but objective assessment revealed their effectiveness to be marginal.
However, of said there are techniques under investigation which involve refilling the capsule with a polymer or creating accommodative lenses that truly undergo a change in optical power by virtue of an increase in surface curvature. These lenses are more efficient and could produce up to 7D of accommodation, according to Dr Glasser.
“Although I believe that accommodation restoration concepts have thus far been disappointing, there are many different approaches being investigated, including some very interesting IOL ideas that are coming down the pipeline, and I believe that these may hold some tremendous hope for the future,” he said.
Debate on light and AMD
Milind Pandé pulled no punches in his presentation on the use of blue-blocking lenses in the session on IOLs and age-related macular degeneration (AMD). There are, he said, only two documented risk factors for AMD: age and smoking. A 1982 study suggested a link to phototoxicity but “there is no credible evidence that low level blue light causes AMD”, according to Mr Pandé. He added that there is a weak correlation between cataract surgery and AMD, with nine of 11 studies showing no link at all.
A major potential downside to using yellow IOLs is that they could disrupt the regular day-night cycle which is ordinarily guided by blue light. Irregularities in this cycle can lead to sleep disorders, depression, diabetes, and even Alzheimer’s disease. “It doesn’t make senses to block blue light 24 hours a day in order to prevent AMD. The link between blue light and AMD is debatable and it’s not worth the risk of having sad, sleep-deprived patients,” he said, adding that sunglasses offer an ideal solution with none of the downsides.
Fiona Cuthbertson then outlined the mechanisms of light damage and the evidence suggesting a link between blue light and a form of AMD. There is, she said, no clear-cut answer at present as to whether blue light is responsible for macular degeneration, but animal and in vitro studies support the link. “In my opinion, there is no convincing reason not to use blue-blocking lenses at this stage,” she said.
Charles Claoué highlighted an ongoing study in Belgium where surgeons are explanting yellow lenses from depressed patients to see if it makes them better. He also hypothesised that the good mood of happy cataract patients is enhanced because their circadian rhythms have been reset and they are sleeping better since their surgery.
Free papers and prizes
The issues of sleep in cataract patients was one that Ms Cuthbertson returned to in her presentation at the Free Paper session on Friday morning. Some 731 cataract patients were asked to complete a sleep questionnaire before surgery and followed up at one month and six months. Patients with abnormal sleep scores prior to the implantation of clear, UV-blocking lenses reported improved sleep afterwards, she said. This led her to conclude that UV-blocking lenses may improve sleep.
Nathaniel Knox-Cartwright scooped the prize for UKISCRS Best Overall Paper in recognition of his presentation on IOL power optimization, and was also awarded the Alcon Prize for Best Poster. The AMO Prize for Best Refractive Paper went to Mr Spokes for a study on descemet stripping endothelial keratoplasty (DSEK), while the Spectrum Prize for Best Cataract Surgery Paper was won by Georgia Cleary. Her prospective, randomised comparison of the accommodative performance of the Bag-in-the-Lens IOL showed there to be no accommodative or near visual advantage over a conventional in-the-bag IOL.
The Friday afternoon session featured the Video Symposium of Challenging Cases. From a range of fascinating and skillful presentations, T Islam and Y M Salah El Din were awarded the Bausch and Lomb prize for Best Video. Their presentation focused on a case of severe bilateral post-lasik keratitis, treated with penetrating keratoplasty and amniotic membrane graft.
Glaucoma takes centre stage
As part of the symposium on glaucoma, Gus Gazzard discussed the timing of lens removal in patients with narrow angles. He presented the treatment options for primary angle closure glaucoma but said it is largely an “evidence light area”, making it difficult to provide clear recommendations. This was followed by illuminating talks by Sheng Lim and Philip Bloom, before Clive Peckar wrapped up the session by discussing Schlemm’s canal surgery and IOL strategy in chronic glaucoma with cataract.
Choyce Medal lecture
The highlight of the second day in Leeds was the Choyce Medal Lecture given by Sheraz Daya. He said Peter Choyce, after whom the medal is named, pushed boundaries, was “incredibly good at adopting technology and had no fear”. In a speech entitled “a corneoplastic journey”, Mr Daya presented a tour de force, outlining the progress that had been made in recent decades.
He said technological innovations have played a major role in changing the face of refractive surgery and that the industry deserved credit for its contribution to change. Describing what he called “a pot pourri” of the contributions made by surgeons at East Grinstead over the past 60 years, he said surgeons would not have made such strides without the tools of the trade which are developed by companies dedicated to innovation.
Mr Daya went to describe the role of stem cells in successful corneal transplantation. Using a series of videos, he showed how he and colleagues have pioneered ex-vivo stem cell allografts using cadaveric cornea. The tissue is currently prepared on site and lasts just a couple of hours, but work is underway to investigate how these cells can be transported to other parts of the UK for surgery.
Association of Ophthalmologists Lecture: New health regulator
Prof Daniel Keenan from the Care Quality Commission said the new healthcare regulator is bringing several bodies together under a single entity. The CQC, established in April this year, will champion joined-up thinking, according to Prof Keenan, who said closer ties between diabetes services and ophthalmology would help bridge gaps for patients who need a range of specialist care.
Enforcing common standards of quality, safety and patient rights will be priorities for the agency, which can fine those who fail to comply with regulations. He said Primary Care Trusts and independent hospitals should publish “quality accounts” in the same way as they current publish financial accounts. This will help focus hospital boards on improving quality, he said.
Annual General Meeting
At the AGM, Charles Claoué, secretary of the society, said membership had increased by 10% on last year, bringing the number of members to 493. He also encouraged members to visit the Eurequo website (www.eurequo.org) which has been funded by the European Union to examine surgical outcomes.
Tayo Akingbehin, President of UKISCRS, thanked members for the faith they placed in him when he was elected. “The society continues to go from strength to strength financially and also in terms of membership,” he said. “I thank all those who contribute to the society and have helped it to grow, and to everyone who helped make this event a success.” The president said the event in Leeds had been a testament to all involved.
The next annual meeting will take place in November 2010 at the Brighton Dome, the venue of the 2008 event. This will be preceded by the satellite meeting in Liverpool on Monday 24th May.