Cataract & Refractive (page 4)
A look at imaging and diagnostics during 2007 and what the future holds.
Imaging & diagnostics going from strength to strength
Something that is certainly helping surgeons to improve outcomes with IOL implantations is the development of analytical models, which allow the analysis of the intraocular performance of lenses based on light scattering and aberrations. "The fact that we can do this will solve a lot of problems related to our understanding of a patient's symptoms in the future. For example, I have been able to make a diagnosis in symptomatic patients by identifying minor IOL malpositioning, which would not ordinarily have been evident but was noticeable upon analysis of intraocular aberrations and scattering," noted Dr Alió.
"This is very important for the future; I am sure that the new instrumentation that is becoming available is going to play a crucial role in our decision-making processes. In particular, it will help us when IOL substitution is required and it will also help us to make the correct IOL selections for our patients," added Dr Alió.
"…the new instrumentation that is
becoming available is going to play
a crucial role in our decision-
making processess… it will help us
when IOL substitution is required
and it will also help us make the
correct IOL selections"
Professor Dick made particular reference to a tool that has assisted him a great deal - the high-resolution Scheimpflug digital imaging device, Pentacam (Oculus). This device contains software that simulates the implantation of a phakic IOL. As a result, the surgeon can see the changes that phakic IOL implantation will induce thus allowing the selection of a lens that will fit perfectly within the eye without damaging any of the vulnerable ocular structures. "This tool allows you to anticipate the age-related changes in the anterior chamber so you can tell whether a phakic lens will be safe in a decade or so," enthused Professor Dick. He continued, "It is absolutely essential that we counsel the patient and measure them precisely so that we are sure that they will be safe. We do not want a repeat of the angle-fixated phakic lens disaster."
Dr Vergés has also been particularly impressed by the Pentacam and, along with Zeiss' Visante OCT and Ellex's Eye Cubed, feels that these devices have made a significant impact in the field of diagnostics and imaging in 2007.
In addition, Professor Dick gives praise to Zeiss' CRS Master aberrometer, which permits the objective measurement of accommodation. "This product allows us to measure any surgical treatment of presbyopia to see if it works or not. It is objective, and extremely reliable," he said. In fact, Dr Matthias Elling was a best oral paper of session winner at this year's ASCRS with his presentation, which demonstrated the intra- and inter-individual independency and high reproducibility of this device.4 "This study demonstrated just how important this device can be to our practices and our presbyopic patients," confirmed Professor Dick.
Are surgeons following the recommendations of the endophthalmitis study?
Moving onto another topic that has roused much attention recently, particularly in the wake of the ESCRS study last year: endophthalmitis.
Indeed, one of the shock announcements of 2006 was the ESCRS endophthalmitis study, which not only implied that clear corneal incisions and silicone IOLs were risk factors in post-cataract endophthalmitis but, importantly, it revealed that a group that received 1 mg of intracameral cefuroxime at the end of surgery effectively achieved a five-fold reduction in endophthalmitis compared with the group that received no perioperative antibiotics.
"I never used intracameral
antibiotics in the past, however, in
light of the ESCRS study, I have
started adding a small amount of
vancomycin to my BSS during
surgery… surprisingly we have seen
a reduction in subclinical infections"
At the study's conclusion, lead investigator, Peter Barry, recommended that intracameral cefuroxime should be adopted worldwide. But have the cataract surgeons worldwide taken Dr Barry's advice?
"I never used intracameral antibiotics in the past, however, in light of the ESCRS study, I have started adding a small amount of vancomycin to my BSS during surgery. Thankfully endophthalmitis has always been rare but surprisingly we have seen a reduction in subclinical infections," said Dr Franchini.
Dr Alió does believe that European surgeons have taken Dr Barry's advice on board and began changing their standard practice this year to accommodate the new endophthalmitis prophylaxis regimen. He also believes that the global medical profession is following suit. "The endophthalmitis study was the first, systematic, multicentre study that clearly demonstrated the prevention of endophthalmitis based on intraocular use of an antibiotic, such as cefuroxime, which is cheap and easy to use. From my experience, this is now the most frequently used method of endophthalmitis prevention in Europe," Dr Alió added.
Dr Faschinger admitted that, although practice patterns in Europe did change in 2007, he has not altered his endophthalmitis prevention regimen because he has not seen a case of endophthalmitis in his surgery in the last 12 years, having performed around 11,000 cataract surgeries. "I strongly rely on povidone iodine, meticulous patching of the lashes, rapid and safe surgery, and postoperative subconjunctival antibiotics, which remain in the anterior chamber for longer than intracameral antibiotics," he said. He also declared that he performs 2.5 mm limbal clear corneal incisions without antibiotics in the irrigation solution. "A posterior capsule tear is very rare (about 1 in 700 operations) and it's always my fault, rather than a result of the procedure."
