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EW CORNEA 70 February 2016 and simple tests, such as TBUT and Schirmer's test, until we reach a more precise definition of the sever- ity of dry eye disease. This will allow us to identify subjects with more or less severe DED and enroll uniform populations in clinical trials," Dr. Aragona said. Clear differentiation between severe and moderate dry eye will also help physicians to choose between a more or less aggressive treatment. "Association of cyclosporine or corticosteroids to tear substitutes is needed in severe DED patients in order to break the vicious circle of chronic inflammation and contin- ue the therapy with less aggressive medications, such as tear substitutes. If we don't identify these patients, and use tear substitutes as first-line treatment in all our patients, there will be cases where under treatment or delayed treatment leads to treat- ment-refractory disease and perma- nent damage," Dr. Aragona said. EW Reference 1. Baudouin C, et al; ODISSEY European Consensus Group members. Diagnosing the severity of dry eye: a clear and prac- tical algorithm. Br J Ophthalmol. 2014; 98(9):1168–76. Editors' note: Dr. Aragona has no fi- nancial interests related to this article. Contact information Aragona: paragona@unime.it by Timothy Norris EyeWorld Contributing Writer (DEWS) II, and may be included in the DEWS report in about 2 years. Precise diagnosis, better management "We start from one of the most com- mon symptom questionnaires, the Ocular Surface Disease Index (OSDI), and then we stain the corneo-con- junctival surface with fluorescein (CFS). We were keen to start from easily identifiable parameters that could be used by less equipped medical centers and are sufficient to adequately evaluate severity for the majority of patients," Dr. Aragona said. With a positive answer in both cases, OSDI higher than 33 with a severe symptomatology and positivity to fluorescein stain- ing above the value of 3 (Oxford scheme), the patient is with no doubt affected by severe dry eye and no additional tests are needed. But in case of discordance be- tween signs and symptoms—when OSDI and CFS are not in agreement —there are 3 possible scenarios: severe symptoms (OSDI >33) with negative or very low CFS score (CFS <1); severe symptoms with mild positivity to fluorescein (CFS grade 2); relatively mild symptoms in pres- ence of significant ocular damage shown by high fluorescein score (CFS >3). "According to one or the other of these scenarios, we can integrate our diagnostic procedure with additional determinant criteria picture of severe surface damage," Dr. Aragona explained. Discordance between signs and symptoms occurs in approximately 50% of the patients, he said. A new algorithm A group of European experts, the multinational ODISSEY European Consensus Group, was set up to create an algorithm for the diagno- sis of severe DED, based on specific clinical signs, on a symptom ques- tionnaire, and on targeted, addition- al tests when needed. "This will allow us to select pa- tients based on precise and uniform criteria, leading to a homogeneous population for clinical trials," Dr. Aragona said. A first report of the group was published in the British Journal of Ophthalmology in March 2014, 1 leading to the adoption of a new se- lection protocol for the enrollment of patients with severe dry eye in a number of European trials. "We have gained a lot from this new protocol. We can better evaluate treatment efficacy also in relation to vehicles. Quite often in clinical trials, vehicles were a confounding factor because in a non-homogeneously selected population the vehicle alone might improve signs and symptoms in pa- tients with less severe dry eye," Dr. Aragona said. Adoption of the new algorithm for DED evaluation will be discussed within the Dry Eye WorkShop The algorithm was developed by a multinational European consensus group to facilitate assessment of disease severity L ack of accuracy in patient selection is a major cause of failure of clinical trials for dry eye disease (DED) treat- ment based on cyclospo- rine or other compounds. For this reason, physicians started to feel the need for a new algorithm capable of accurately selecting patients with different levels of dry eye severity. According to Pasquale Aragona, MD, professor of ophthalmology, University of Messina, Italy, clinical trial failures are usually due to a discordance between signs and symptoms of dry eye. "While some patients have very evident symptoms but no clinical signs that can be detected through eye examination, other patients show some very clear signs on the surface of the eye but suffer no symptoms at all," he said. This can be explained if we con- sider that DED pathogenesis is close- ly linked to corneal innervation. "If corneal innervation is com- promised, as it might be in cases of advanced-stage dry eye, symptoms may not be so apparent and are inconsistent with the clinical New scoring algorithm leads to precise diagnosis of severe dry eye disease undergone LASIK and PRK would be good candidates for femtosecond laser use. These patients tend to love the idea of using the laser again, she said, and the corneas are clear. Patients with prior penetrating ker- atoplasty (PK), Descemet's stripping endothelial keratoplasty (DSEK), and deep anterior lamellar keratoplasty (DALK) are certainly good candi- dates. "We have to remember that the cornea has to be clear," she said. Patients with pre-existing cor- neal conditions also require special considerations when deciding if it's appropriate to use the femtosecond laser. These would include patients with keratoconus, Fuchs' dystrophy, corneal scarring, or pterygium. With all of these conditions, there are both good and bad candidates. Dr. Donaldson said that particularly for those with corneal scars, central cor- neal scars could block laser penetra- tion. Similarly, there are some good candidates with Fuchs' dystrophy. Guttata is fine, Dr. Donaldson said, but significant corneal edema or opacities would make the patient a bad candidate. When we talk about Fuchs' dystrophy, she said, we can use much less ultrasound energy when we apply FLACS pre-treatment for lens softening and fragmenta- tion. "We're hoping this will trans- late into preservation of endothelial cells." Smaller pterygia are also fine in conjunction with the femtosec- ond laser, but larger pterygia are not as they may infringe on the area of laser penetration and may interfere with maintenance of patient inter- face suction. The integration of technology is key to give surgeons the best results, Dr. Donaldson said. In conclu- sion, she said that FLACS may be performed in patients with some corneal pathology or prior corneal surgery. Always weigh the risks and benefits, she said, and always set realistic expectations. EW Editors' note: Dr. Donaldson has financial interests with Abbott Medical Optics (Abbott Park, Ill.) and Alcon (Fort Worth, Texas). Contact information Donaldson: kdonaldson@med.miami.edu Femtosecond laser continued from page 68

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