Cornea - ARVO

ARVO 2013 Annual Meeting Abstracts by Scientific Section/Group - CorneaPinkas, None; Ruth Goldschmidt, None; Vyacheslav Kalchenko,None; Daniel H. Wagner, Weizmann Institute (P); YoramSalomon, Yeda (P); Avigdor Scherz, Yeda, Weizmann Inst scie (P)Support: Gurwin FoundationProgram Number: 5290 Poster Board Number: C0209Presentation Time: 2:45 PM - 4:30 PMAntimicrobial efficacy of riboflavin / UV-A collagen cross-linkingat different fluences in vitroFlorence Hoogewoud, Olivier Richoz, Farhad Hafezi. Ophtalmology,University Hospital of Geneva, Geneva, Switzerland.Purpose: Infectious corneal ulceration is a common cause of visualloss. The final outcome is influenced by early diagnosis andtraditionally by intensive treatment with topical antibiotics. UV-Aactivated riboflavin (corneal collagen crosslinking (CXL) representsa new potential therapeutic approach. Its mechanism of action isclosely linked to the abundant generation of free radicals. Generationof free radicals is an intensity- and time-dependent process. Thestudies performed so far have all used the standard protocol (3mW/cm2 during 30 min) that had been established for progressivekeratoconus. Our study investigates the antimicrobial efficacy ofCXL using three different intensities and time regimen whilemaintaining the same total energy dose.Methods: A porous polymer 300 μm thick, containing 96% of water,not toxic for the bacteria and not UV-absorbing was used as a supportfor the experiment. Two solutions of 106 bacteria, one of methicillinresistantStaphylococcus aureus and one of Pseudomonas aeruginosa,combined with 0.1% Riboflavin solution were instilled in thepolymer. Three different protocols of UV-irradiation (365nm) usingthe same energy (5.4 mJ) at different time and power settings weretested (3 mW/cm2 during 30 min; 9 mW/cm2 during 10 min; 18mW/cm2 during 5 min). After irradiation, the solution was culturedon a blood agar plate and the CFU (colony forming units) werecounted after 24h of incubation. Controls without riboflavin and withriboflavin but without irradiation were performed.Results: At the three different intensities, the number of bacteria wasreduced by 2 log(10) scales compared with both control groups. Nosignificant differences were detected between the three protocols.Conclusions: The bactericidal rate was comparable in all threeprotocols tested suggesting that in clinical practice the time-sparingprotocol (18 mW/cm2 during 5 min) should provide as good resultsas the standard protocol (3 mW/cm2 during 30 min). Clinical trialswill have to confirm this hypothesis.Commercial Relationships: Florence Hoogewoud, None; OlivierRichoz, None; Farhad Hafezi, Schwind (F), Ziemer (F), PCT/CH2012/000090 (P)Program Number: 5291 Poster Board Number: C0210Presentation Time: 2:45 PM - 4:30 PMCombination of Intracorneal ring segments (Ferrara and Intacts)in the care of patients with KeratoconusRoberto Albertazzi 1 , leonardo ferlini 1 , Luciano D. Perrone 1 , DanielM. Perrone 1 , Guillermo Rao 1 , José F. Alfonso 2, 3 , Jesus Merayo-Lloves 2, 3 . 1 centro de ojos quilmes, Quilmes, Argentina; 2 Fundaciónde Investigacion Oftalmologica - Instituto Oftalmológico Fernández-Vega, oviedo, Spain; 3 University of Oviedo, oviedo, Spain.Purpose: Outcome Analyisis of a combination of Intracorneal ringsegment (ICRS) both Ferrara and Intacts, for tectonic and refractivecorrection of paracentral keratoconus.Methods: 43 eyes of 33 patients with contact lens intolerance orprogressive paracentral keratoconus underwent ICRS surgery andwere followed for 1 at least 6 months. Patients were divided in twogroups acording with the coincidence of axis of astigmatism andcoma as Group I, +- 30° coincident, croissant shape and Group II,non coincident (30-75°), duck shape. Surgery were performedmanually and ICRS were implanted at 6 mm of the optical axis: 150°Ferrara ICRS were placed temporal-inferiorly and 90° intacs werelocated nasal-superiory. Tectonic outcome were evaluated as areduction of the keratometric (K) values: K minimal (Kmin) and Kmaximal (Kmax)).Visual outcome were measured as improve inuncorrected distance visual acuity (UDVA), best corrected visualacuity (CDVA), and refractive error (miopia and astigmatism)redcution (decimal scale). Data were processed with R-programinglanguage for descriptive ans inference statistical análisis análisisResults: There were a significant (p