Browsing by Author "Paschalis, Eleftherios I."
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- ItemAngle Anatomy and Glaucoma in Patients With Boston Keratoprosthesis(2020) Silva, Rafaella Nascimento e; Taniguchi, Elise V.; Cruzat Corssen, Andrea; Paschalis, Eleftherios I.; Pasquale, Louis R.; Colby, Kathryn A.; Dohlman, Claes H.; Chodosh, James; Shen, Lucy Q.Purpose: To quantitatively analyze the angle anatomy in eyes with a Boston type 1 keratoprosthesis (KPro) using anterior segment optical coherence tomography (AS-OCT) and to assess the diagnostic ability of AS-OCT in KPro-associated glaucoma. Methods: AS-OCT (RTVue) images from KPro eyes with and without glaucoma were reviewed. The angle opening distance at 500 mu m from the scleral spur (AOD500), trabecular-iris angle at 500 mu m from the scleral spur (TIA500), and trabecular-iris surface area at 500 mu m from the scleral spur (TISA500) were measured by 2 observers masked to the diagnosis. The measurements for each visible quadrant were compared between KPro eyes with and without glaucoma. Results: Twenty-two eyes with glaucoma and 17 eyes without glaucoma from 39 patients with KPro were included. Of the 4 quadrants imaged, the temporal angle was the most visible (79.5%) and angle measurements of the temporal quadrant were the only ones that differentiated the 2 groups: the mean AOD500, TIA500, and TISA500 were significantly lower in KPro eyes with glaucoma than without glaucoma (388.2 +/- 234.4 mu m vs. 624.5 +/- 310.5 mu m,P= 0.02; 26.1 +/- 14.0 degrees vs. 39.1 +/- 17.1 degrees,P= 0.03; and 0.15 +/- 0.09 mm(2)vs. 0.23 +/- 0.12 mm(2),P= 0.03; respectively). The highest area under the receiver operating characteristic curve for detecting glaucoma was 0.75 for temporal TIA500 (95% confidence interval 0.57-0.94,P= 0.02) with 50% specificity at 80% of sensitivity and a cutoff value of 37 degrees. Conclusions: The temporal angle was the most visible on AS-OCT in eyes with a KPro. Significant narrowing of the temporal angle detected on AS-OCT was associated with glaucoma in these eyes.
- ItemEffects of gamma radiation sterilization on the structural and biological properties of decellularized corneal xenografts(2019) Islam, Mohammad Mirazul; Sharifi, Roholah; Mamodaly, Shamina; Islam, Rakibul; Nahra, Daniel; Abusamra, Dina B.; Chuen Hui, Pui; Adibnia, Yashar; Goulamaly, Mehdi; Paschalis, Eleftherios I.; Cruzat Corssen, Andrea; Kong, Jing; Nilsson, Per H.; Argüeso, Pablo; Mollnes, Tom Eirik; Chodosh, James; Dohlman, Claes H.; González-Andrades, MiguelTo address the shortcomings associated with corneal transplants, substantial efforts have been focused on developing new modalities such as xenotransplantion. Xenogeneic corneas are anatomically and biomechanically similar to the human cornea, yet their applications require prior decellularization to remove the antigenic components to avoid rejection. In the context of bringing decellularized corneas into clinical use, sterilization is a crucial step that determines the success of the transplantation. Well-standardized sterilization methods, such as gamma irradiation (GI), have been applied to decellularized porcine corneas (DPC) to avoid graft-associated infections in human recipients. However, little is known about the effect of GI on decellularized corneal xenografts. Here, we evaluated the radiation effect on the ultrastructure, optical, mechanical and biological properties of DPC. Transmission electron microscopy revealed that gamma irradiated decellularized porcine cornea (G-DPC) preserved its structural integrity. Moreover, the radiation did not reduce the optical properties of the tissue. Neither DPC nor G-DPC led to further activation of complement system compared to native porcine cornea when exposed to plasma. Although, DPC were mechanically comparable to the native tissue, GI increased the mechanical strength, tissue hydrophobicity and resistance to enzymatic degradation. Despite these changes, human corneal epithelial, stromal, endothelial and hybrid neuroblastoma cells grew and differentiated on DPC and G-DPC. Thus, GI may achieve effective tissue sterilization without affecting critical properties that are essential for corneal transplant survival. (C) 2019 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
- ItemThe Role of the Back Plate in Angle Anatomy with the Boston Type I Keratoprosthesis(2017) Taniguchi, Elise V.; Paschalis, Eleftherios I.; Crne, Aljaj; Ren, Ai; Colby, Kathryn A.; Chodosh, James; Pasquale, Louis R.; Shen, Lucy Q.; Dohlman, Claes H.; Cruzat Corssen, Andrea