EyeWorld Asia-Pacific September 2011 Issue

28 September 2011 EW REFRACTIVE A patient’s pre- and post-collagen crosslinking topography. Doctors now have a variety of options for treating ectasia, including crosslinking, intracorneal rings, and phakic IOLs Source: A. John Kanellopoulos, MD Patients have more options than ever C orneal transplantation for keratoconus may soon be a thing of the past, according to a study from the cornea clinical committee of the American Society of Cataract & Refractive Surgery to be published in a forthcoming issue of the Journal of Cataract and Refractive Surgery . Authors Jose Güell, MD, PhD, associate professor of ophthalmology, Autonomous University of Barcelona, Spain, and Sheraz Daya, MD, medical director, Center for Sight, London, England, UK, present readers with a comprehensive overview of the current surgical management strategies available for progressive, non-inflammatory corneal thinning. Ectasia comes in many forms, the most common being keratoconus. Likewise, treatment options for ectasia and keratoconus are numerous. Where do we stand at the moment? What evidence is there to suggest these alternative therapies provide a benefit to patients? Those are the questions Drs. Güell and Daya attempt to answer in their paper, “Surgical Management of Ectasia”. “In Europe, we have access to a lot more therapeutic methodologies than US surgeons,” said Dr. Daya. “With all of these different methodologies, the paradigm of how to treat keratoconus is changing. A lot of these therapies are investigational. For instance, doing photorefractive keratectomy and crosslinking the cornea at the same time is investigational but seems to have some validity. There are so many The surgical management of ectasia by Faith A. Hayden EyeWorld Staff Writer different methodologies available, where do they all fit in?” The authors acknowledged that patient management strategies vary widely from country to country and often depend on the surgeon’s experience and skill level, as well as available technology and severity of the patient’s condition. “For example, crosslinking is not yet accepted in the US,” Dr. Güell said. “It’s still under FDA approval. But intracorneal rings can be used in the US and in Europe.” Traditionally, management has been glasses followed by contact lenses, and that method represents the treatment of choice in 90% of patients. If contacts failed, then often surgeons would go straight to a corneal transplant. “That’s changed now with all of these different methodologies,” Dr. Daya said. “We can delay transplantation, rehabilitate vision using other methods, and may eliminate transplantations altogether. If we do a transplant we can do one that is less risky and almost eliminate the chance of corneal blindness.” Drs. Daya and Güell list a number of alternative management options such as collagen crosslinking combined with topographic guided photorefractive keratectomy, intracorneal ring segments, phakic IOLs, and as a last resort, corneal transplantation, while also including surgical techniques, clinical outcomes, and possible complications. For example, complications for intracorneal ring segments, although rare, include microbial keratitis, implant extrusion, corneal thinning in the area over the segment, and reduced corneal sensation. “The formation of white, fine deposits is frequent inside the tunnels around the segments,” the researchers wrote. “The incidence and density of the deposits increases with the thickness of the segment and the implantation time. Among the visual symptoms reported by the patients are diplopia, halos, difficulty in night vision, vision fluctuation, and photophobia.” For phakic IOLs, the researchers go over how to implant a Collamer Lens (STAAR Surgical, Monrovia, Calif., USA/ Nidau, Switzerland), calling it an “attractive alternative for correcting myopic and astigmatic defects in patients with a stable keratoconus”. The greatest impact, though, will come from collagen crosslinking, stated the researchers. “Collagen crosslinking probably shows great promise and based on current data will have the greatest impact in hopefully reducing or delaying progression of keratoconus, allowing patients to tolerate spectacles and contact lenses,” they wrote. “The traditional approach to keratoconus is done, which is fortunate for this group of patients,” said Dr. Daya. “This condition is not uncommon. In the UK, the prevalence is about 1 in 2,000. For a fairly common disease, we have a lot more options available. It used to be miserable for these patients, but we can do a lot more for them now.” EW Editors’ note: Drs. Daya and Güell have no financial interests related to their comments. Contact information Daya: sdaya@centreforsight.com Güell: guell@imo.es