Browsing by Author "Vinciguerra, Riccardo"

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    Corneal Endothelial Cell Loss in Glaucoma and Glaucoma Surgery and the Utility of Management with Descemet Membrane Endothelial Keratoplasty (DMEK)
    (2022) Vallabh, Neeru A.; Kennedy, Stephnie; Vinciguerra, Riccardo; McLean, Keri; Levis, Hannah; Borroni, Davide; Romano, Vito; Willoughby, Colin E.; Department of Doctoral Studies
    The corneal endothelium has a crucial role in maintaining a clear and healthy cornea. Corneal endothelial cell loss occurs naturally with age; however, a diagnosis of glaucoma and surgical intervention for glaucoma can exacerbate a decline in cell number and impairment in morphology. In glaucoma, the mechanisms for this are not well understood and this accelerated cell loss can result in corneal decompensation. Given the high prevalence of glaucoma worldwide, this review aims to explore the abnormalities observed in the corneal endothelium in differing glaucoma phenotypes and glaucoma therapies (medical or surgical including with new generation microinvasive glaucoma surgeries). Descemet membrane endothelial keratoplasty (DMEK) is increasingly being used to manage corneal endothelial failure for glaucoma patients and we aim to review the recent literature evaluating the use of this technique in this clinical scenario.
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    Expression of VEGF-A, otx homeobox and p53 family genes in proliferative vitreoretinopathy
    (2013) Azzolini, Claudio; Pagani, Ilaria Stefania; Pirrone, Cristina; Borroni, Davide; Donati, Simone; Al Oum, Muna; Pigni, Diana; Chiaravalli, Anna Maria; Vinciguerra, Riccardo; Simonelli, Francesca; Porta, Giovanni
    Introduction. Proliferative vitreoretinopathy (PVR) is a severe inflammatory complication of retinal detachment. Pathological epiretinal membranes grow on the retina surface leading to contraction, and surgery fails in 5% to 10% of the cases. We evaluated the expression of VEGF-A, Otx1, Otx2, Otx3, and p53 family members from PVR specimens to correlate their role in inducing or preventing the pathology. Methods. Twelve retinal samples were taken from patients affected by PVR during therapeutic retinectomies in vitreoretinal surgery. Gene expression was evaluated using quantitative real-time reverse transcriptase PCR analysis and immunohistochemistry, using four healthy human retinae as control. Result. Controls showed basal expression of all genes. PVR samples showed little or no expression of Otx1 and variable expression of VEGF-A, Otx2, Otx3, p53, and p63 genes. Significant correlation was found among VEGF-A, Otx2, p53, and p63 and between Otx1 and Otx3. Conclusions. Otx homeobox, p53 family, and VEGF-A genes are expressed in PVR human retina. We individuated two possible pathways (VEGF-A, Otx2, p53, p63 and Otx1 and Otx3) involved in PVR progression that could influence in different manners the course of the pathology. Individuating the genetic pathways of PVR represents a novel approach to PVR therapies.
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    The "yogurt" Technique for Descemet Membrane Endothelial Keratoplasty Graft Preparation : A Novel Quick and Safe Method for Both Inexperienced and Senior Surgeons
    (2020-09-01) Tzamalis, Argyrios; Vinciguerra, Riccardo; Romano, Vito; Arbabi, Esmaeil; Borroni, Davide; Wojcik, Gabriela; Ferrari, Stefano; Ziakas, Nikolaos; Kaye, Stephen
    Purpose:To describe and evaluate the efficacy and safety of a novel technique to prepare Descemet membrane endothelial keratoplasty (DMEK) donor grafts using a newly designed partial-thickness hinge punch.Methods:The novel punch has a circular guarded blade missing 1 clock hour, creating an uncut hinge on the donor cornea. In addition, 2 straight cuts are made by the punch perpendicular to the edge of trephination toward the trabecular meshwork in the hinge area. After the donor corneoscleral rim is positioned endothelial side up, a partial-thickness trephination is performed avoiding any rotational movements. Descemet membrane is lifted from Schwalbe line in the hinge area, and DMEK graft is peeled after desired marking without further preparation.Results:Three surgeons of different experience levels on DMEK (senior/independent/fellow) initially applied the new technique in 18 research corneas, divided into equal groups. Two failures in graft preparation were noted, defined as radial tears extending ≥0.5 mm. The mean preparation time was 6.21 ± 1.45 minutes. No statistically significant differences were noted in success rate, duration, and endothelial cell loss (ECL) between surgeons (P > 0.05). ECL was evaluated as an average of 5 readings on randomly selected graft areas, not including graft periphery. Fifteen additional research corneas were stripped by 1 single user in an eye bank setting. No tissue loss was recorded, whereas ECL and mortality rate remained unaffected after preparation (P = 0.64 and P = 0.72, respectively).Conclusions:This new DMEK graft preparation technique, simulating the opening of a yogurt cup, seems to be a safe and an efficient method, providing shorter preparation time and low failure rates independent of surgeon's experience level.