Time filter

Source Type

Scorcia V.,University of Catanzaro | Cosimo F.D.,University of Catanzaro | Lucisano A.,University of Catanzaro | Ponzin D.,International Center for Ocular Physiopathology | And 2 more authors.
Cornea | Year: 2015

Purpose: The aim of this study was to describe clinical outcomes and histopathologic findings in a case of repeat deep anterior lamellar keratoplasty (DALK) performed because of inadvertent inversion of the donor button at the time of primary surgery.Methods: A 34-year-old woman underwent big-bubble DALK for keratoconus in her right eye; 4 days postoperatively, slit-lamp examination revealed the presence of several inclusions in the interface, whereas anterior segment optical coherence tomography (AS-OCT) showed pathologically marked wrinkling of the posterior stroma; inadvertent intraoperative inversion of the graft was diagnosed and the interface inclusions were assumed to be of epithelial origin. Repeat surgery was performed: donor tissue was removed and submitted to histological examination, marking the external surface of the lamella; the recipient residual bed was carefully washed and a new lamellar graft was sutured into position. Three months postoperatively, the patient underwent a complete ophthalmologic examination, including best-spectacle corrected visual acuity testing, refraction, biomicroscopy, AS-OCT, and endothelial microscopy.Results: Histological examination confirmed that the donor button had been implanted with the epithelium facing the residual bed. Three months postoperatively, normal corneal curvature was visible at AS-OCT, the best-spectacle corrected visual acuity was 20/25, and the interface appeared perfectly clear. Endothelial cell density had not been substantially affected by the 2 surgical procedures.Conclusions: Inadvertent inversion of donor tissue at the time of DALK is reported for the first time. Prompt exchange of the lamellar graft was instrumental in avoiding epithelial colonization of the interface, as well as in restoring excellent vision. Copyright © 2014 by Lippincott Williams & Wilkins.

Parekh M.,International Center for Ocular Physiopathology | Ferrari S.,International Center for Ocular Physiopathology | Sheridan C.,University of Liverpool | Kaye S.,University of Liverpool | Ahmad S.,University of Liverpool
Stem Cells Translational Medicine | Year: 2016

The cornea forms the front window of the eye, enabling the transmission of light to the retina through a crystalline lens. Many disorders of the cornea lead to partial or total blindness, and therefore corneal transplantation becomes mandatory. Recently, selective corneal layer (as opposed to full thickness) transplantation has become popular because this leads to earlier rehabilitation and visual outcomes. Corneal endothelial disorders are a common cause of corneal disease and transplantation. Corneal endothelial transplantation is successful but limited worldwide because of lower donor corneal supply. Alternatives to corneal tissue for endothelial transplantation therefore require immediate attention. The field of human corneal endothelial culture for transplantation is rapidly emerging as a possible viable option. This manuscript provides an update regarding these developments. © AlphaMed Press 2016.

Parekh M.,International Center for Ocular Physiopathology | Ruzza A.,International Center for Ocular Physiopathology | Ferrari S.,International Center for Ocular Physiopathology | Busin M.,Villa Igea Hospital | Ponzin D.,International Center for Ocular Physiopathology
American Journal of Ophthalmology | Year: 2016

Introduction To determine the feasibility of preloading endothelial tissues for Descemet membrane endothelial keratoplasty (DMEK). Design Laboratory investigation. Methods setting: Institutional. participants: Twenty human donor corneas unsuitable for transplantation with endothelial cell density in a range of 1600-2700 cells/mm2. Intervention: The endothelium was punched, stripped (8.5 mm diameter) and manually tri-folded with the endothelial side inward. The excised membranes were gently moved in a 2.2 intraocular lens (IOL) cartridge and pulled further in the funnel using 25 G end-grasping forceps. The cartridge was filled with transport media (TM) (sealed at its funnel and back entrance with a stopper) and the tissue was preserved for 4 days at room temperature in the bottles containing TM. main outcome measures: Success rate of preparation, processing time, endothelial cell loss (ECL), and active metabolism. Results The tissues were peeled and loaded successfully in all cases. Average stripping and loading time was 20 and 4.5 minutes, respectively. ECL after preservation was 4.35% with 3.55% (± 5.89%) mortality and 7.80% (± 14.12%) uncovered areas. A total of 0.55 (± 0.26) mg/mL of glucose was consumed by the cells showing active metabolism. Conclusions Tri-folded (endothelium-in) DMEK grafts can be preloaded using TM in an IOL cartridge and stored up to 4 days with limited endothelial damage. Direct injection of TM should be avoided because of the presence of bovine serum, but the tissue can be washed using balanced salt solution and gently injected. Alternatively, the graft can be easily delivered using a bimanual pull-through technique. Preloading DMEK grafts will simplify the surgery with reproducibility, reduced surgical time, and reduced tissue wastage, cost, and logistical requirements. © 2016 Elsevier Inc.

Parekh M.,International Center for Ocular Physiopathology | Ferrari S.,International Center for Ocular Physiopathology | Ponzin D.,International Center for Ocular Physiopathology
Eye Banking: Changing Face of Corneal Transplantation | Year: 2015

Until a few years ago, eye banks were only considered as centres for collecting and processing units of human donor eyes. However, eye banks in recent years have changed the process of current corneal transplantation. Although the very first corneal transplantation was conceptualized in the late 18th century, it has taken a century to develop methods and understand the role of human corneas in general. This book gives an insight of worldwide associations and their standard regulations in terms of corneal donations, processes and transplantations. The associations mainly include: Eye Bank Association of America, European Eye Bank Association and Eye Bank Association of Australia and New Zealand. This book also refers to some of the early stages of eye banking and current methods of preservation, including cold and organ culture storage. The current eye banking scenario is changing dramatically in terms of tissue processing. Once, tissues were only collected, stored and shipped for transplantation to the surgeons. Now eye banks have advanced in developing techniques in collaboration with surgeons to introduce more reliable methods of transplantation. This includes standardization of methods such as DSAEK, UT-DSAEK, pre-loaded grafts and DMEK. Furthermore, this compilation describes different techniques of lamellar keratoplasty, such as anterior and posterior lamellar keratoplasties. Retrieving, storing, processing and transplantation of such lenticules are also discussed in this book. Posterior lamellar graft preparation for selective surgeries like DSAEK and Ultra-Thin DSAEK has been included with relevant clinical approaches. DMEK, which is currently taking corneal transplantation to a different level, has been reported with various graft preparation techniques. The role of eye banks in general for such preparation method is also examined. Additionally, the importance of microbiology in day to day care in the field of corneal transplantation and eye banks exists as a topic within these pages. Eye banks are playing a major role and changing the face of corneal transplantation in terms of new research; whether it be graft preparation for surgeries, preservation, surgical tools, ready-to-use tissues or studying cornea in details using available research tissues, these methods are advancing the field. Eye banks play a major role in tissue selection and correct processing methods. Surgeons are provided with a validated tissue so it makes easier for them to follow the transplantation. Therefore, this book highlights the new concepts in the eye banking field with regards to the standards, regulations, retrieval, preservation and transplantation methods. All of these continue to help aid in the research and development of surgical processes and devices. © 2015 by Nova Science Publishers, Inc. All rights reserved.

Ruzza A.,International Center for Ocular Physiopathology | Parekh M.,International Center for Ocular Physiopathology | Ferrari S.,International Center for Ocular Physiopathology | Salvalaio G.,International Center for Ocular Physiopathology | And 5 more authors.
British Journal of Ophthalmology | Year: 2015

Purpose: To design and validate the efficacy of threedimensional (3D) printed smart storage glide (SSG) which is capable of preserving and delivering posterior lenticules for Descemet stripping automated endothelial keratoplasty (DSAEK). Methods: Laboratory investigation (A) was followed by clinical validation (B). Unsuitable corneas for transplantation (n=20) were used for study A. These tissues were cut using a standard microkeratome, punched and loaded into the SSG and preserved for 7 days in transport media. Endothelial cell density (ECD), Trypan blue and Alizarin red staining for endothelial morphology, thickness measurements and glucose uptake, cell apoptosis and immunostaining post preservation were analysed. For study B, clinical grade corneas (n=14) were preloaded in SSG and grafted in patients with indications of Fuchs' dystrophy (n=8), pseudophakic bullous keratopathy (n=3), posterior polymorphous dystrophy (n=2), and previous DSAEK failure (n=1). Standard DSAEK included descemetorhexis under air and bimanual delivery of the tissue under infusion of buffered saline solution through an anterior chamber maintainer placed at the 12 o'clock position. Main outcome measures for study B were less surgical time, best spectacle-corrected visual acuity (BSCVA), speed of visual recovery, and ECD. Results: For study A, an average ECD loss was 2.30 ±3.21%, thickness increased by 30.80±20.85% and one-third of glucose was utilised during the preservation phase. Alizarin red showed hexagonality of the cells. Cell apoptosis was not observed and expression of ZO-1 was noted on the preserved tissues. In study B, 25% ECD loss was observed after 6 months. BSCVA improved to 20/25 or better within 3 months after DSAEK. Mean surgical time recorded was 21 min. Conclusions: This paper describes the development, design, laboratory and clinical validation of a 3D printed SSG which helps to store and deliver posterior lenticules, therefore allowing transportation of quality-controlled precut tissues.

Discover hidden collaborations