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Introduction: Optimization of femtosecond laser characteristics in corneal surgery is still needed to improve clinical results. In this study, we describe an original characterization technique able to measure laser damage of corneal tissues precisely and to provide complementary physical results on the laser-matter interaction., Method: A femtosecond laser was used to damage corneas not suitable for graft. The epithelium and the Bowman layer are exposed to a set of different single-shot fixed laser fluences. Optical microscopy can determine the probability of laser damage on the corneal surface. The high damage threshold (minimum fluence systematically damaging the cornea) roughly fixes the operating laser fluence conditions, while the low damage threshold sets the maximum laser fluence level preserving tissue integrity (safety level)., Results: We precisely evaluate the damage fluence threshold of a tissue, using a statistical approach coupled with optical microscopy analysis. This technique gives essential information on laser-tissue interaction with a high rate of confidence. For corneal epithelium and the Bowman layer, we determine the maximum laser fluence level preserving tissue integrity (safety level) and the minimum fluence level systematically damaging the tissue. High and low threshold fluences of epithelium and the Bowman layers are (5.6 ± 0.4 J/cm(2); 2.7 ± 0.1 J/cm(2)), and (7.1 ± 1.1 J/cm(2); 3.4 ± 0.1 J/cm(2)), respectively., Conclusion: These data constitute determinant parameters for clinical applications, since they determine a working window providing the minimal effective irradiation dose that is mandatory for the development of high-quality laser-cutting surgery processes with minimized side effects., (Copyright © 2010 Elsevier Masson SAS. All rights reserved.)

Micrometer scale resolution full-field optical coherence tomography (FF-OCT) is developed for imaging human graft corneas. Three-dimensional (3-D) images with ultrahigh resolution (respectively, 1 and 1.5 μm in the axial and transverse directions), comparable to traditional histological sections, are obtained allowing the visualization of the cells and the precise structure of the different layers that compose the tissue. The sensitivity of our device enables imaging the entire thickness of the cornea, even in edematous corneas more than 800 μm thick. Furthermore, we provide tomographic 3-D images of laser incisions inside the tissue at various depths without slicing the studied corneas. The effects of laser ablations can be observed, along various optical sections, directly in the bulk of the sample with high accuracy, providing information on the interface quality and also imaging tiny changes of the tissue structure. FF-OCT appears to be a powerful tool for subcellular imaging of the corneal structure and pathologies on the entire thickness of the tissue as well as interface quality and changes in the collagen structure due to laser incisions on ex vivo human cornea.

Background: To compare the effects of different doses of bevacizumab with both saline and dexamethasone on inflammatory angiogenesis in the rat cornea induced by small chemical lesions., Methods: Corneal chemical cauterization was performed on 24 rats. Animals were divided randomly into six groups and received a daily subconjunctival injection for 7 days of: balanced salt solution 0.1 mL or dexamethasone phosphate 4 mg/day or bevacizumab 2.5 mg/day, 3.75 mg/day, 5.0 mg/day or bevacizumab 5.0 mg/day + dexamethasone phosphate 4 mg/day. Clinical examination under slitlamp was performed daily for 7 days to evaluate corneal opacity and vessel size evolution. Computer assisted quantitative image analysis was used to measure the total corneal area covered by neovascularization., Results: At final examination, the dexamethasone, bevacizumab 5.0 mg/day and dexamethasone + bevacizumab groups showed a significant lowering in corneal opacity score as compared with control (P = 0.024, P = 0.006 and P = 0.013, respectively). Also, a significant reduction on new vessels size score was observed. Surface of corneal neovascularization was significantly reduced in dexamethasone, bevacizumab 5.0 mg/day and dexamethasone + bevacizumab groups compared with control (P =0.045, P = 0.047 and P = 0.044, respectively)., Conclusion: Our study demonstrates the ability of a 5.0 mg/day bevacizumab subconjunctival injection, in monotherapy or associated with dexamethasone, to cause a short-term involution of corneal neovascularization after corneal alkali burn. Combination of both of these treatments may have advantages to monotherapy approaches.

Purpose: To evaluate the use of the Femtec femtosecond (fs) laser for penetrating keratoplasty (PK) in the treatment of corneal diseases., Design: Prospective, nonrandomized clinical study., Methods: Nine eyes of nine patients underwent surgery for PK. Five had pseudophakic bullous keratopathy, three had Fuchs dystrophy, and one presented in a keratoconus patient. A Femtec (20/10 PerfectVision; GmbH, Heidelberg, Germany) fs laser was used to create penetrating cuts on donor and recipient corneas. All patients were evaluated for uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), pachymetry, topography, and endothelial cell density (ECD). Scanning electron microscopy (SEM) was performed on corneal tissue after surgery., Results: All eyes were treated successfully without intraoperative complications. The mean follow-up was 6 +/- 3 months. At the last postoperative examination mean BSCVA was 20/69 and there was a significant improvement (P = .08) in both UCVA and BSCVA. Mean astigmatism was 2.9 +/- 1.2 diopters. Mean ECD was 1194 +/- 465 cells/mm(2) with a mean cell loss after surgery of 49.8% +/- 19.8%. SEM displayed smooth rectilinear cut margins and minor remaining tissue bridges. One patient presented a retinal detachment three months after surgery that was successfully treated and two subjects showed an allograft rejection., Conclusion: Use of the Femtec fs laser was effective and safe to perform PK. Short-term visual results and refractive results are analogous to conventional PK or other fs laser-assisted PK studies. Longer-term follow-up of additional cases is necessary to precisely quantify the endothelial cell loss after fs surgery.

Purpose To describe characteristics of a delivery device of endothelial graft using in endothelial keratoplasty procedure (Descemet Stripping Endothelial Keraplasty, DSAEK) and to report clinical results. Methods 20 patients are including in our prospective non‐randomised study. Patients were benefited of a DSAEK by an experienced surgeon. The dissection of the endothelial graft were realised after removal epithelium and cutting a cornea anterior hat of 350μm by a microkeratom (Moria France). Grafts are inserted by the Endosaver® (Ocular System Inc USA) by a 4 mm incision and applied by a buffering of a air bubble in the anterior segment after a peripheral iridotomy. Authors reports experiences with this device and the density of endothelial cells after 6 month. Results Any failure of the graft was reported. The diminution of endothelial cells was correlated to the thickness of the graft and situated between 26% and 31% depending on pachymetry (50‐120 μm and 120‐150μm).49% of patients had more than 20/40 at 6 month. Conclusion our study showed the interest of Endosaver® on endothelial grafts to reduce the incision and the diminution of endothelial cells on DSAEK. [ABSTRACT FROM AUTHOR]