Effect of Air Injection Depth on Big-bubble Formation in Lamellar Keratoplasty: an Ex Vivo Study

This study evaluated the effect of air injection depth in the big-bubble (BB) technique, which is used for corneal tissue preparation in lamellar keratoplasty. The BB technique was performed on ex vivo human corneoscleral buttons using a depth-sensing needle, based on optical coherence tomography (OCT) imaging technology. The needle tip, equipped with a miniaturized OCT depth-sensing probe, was inserted for air injection at a specified depth. Inside the corneal tissue, our needle obtained OCT line profiles, from which residual thickness below the needle tip was measured. Subjects were classified into Groups I, II, III, and IV based on injection depths of 75-80%, 80-85%, 85-90%, and > 90% of the full corneal thickness, respectively. Both Type I and II BBs were produced when the mean residual thicknesses of air injection were 109.7 +/- 38.0 mu m and 52.4 +/- 19.2 mu m, respectively. Type II BB (4/5) was dominant in group IV. Bubble burst occurred in 1/16 cases of type I BB and 3/16 cases of type II BB, respectively. Injection depth was an important factor in determining the types of BBs produced. Deeper air injection could facilitate formation of Type II BBs, with an increased risk of bubble bursts

Chromosome evolution in Cophomantini (Amphibia, Anura, Hylinae)

The hylid tribe Cophomantini is a diverse clade of Neotropical treefrogs composed of the genera Aplastodiscus, Boana, Bokermannohyla, Hyloscirtus, and Myersiohyla. The phylogenetic relationships of Cophomantini have been comprehensively reviewed in the literature, providing a suitable framework for the study of chromosome evolution. Employing different banding techniques, we studied the chromosomes of 25 species of Boana and 3 of Hyloscirtus; thus providing, for the first time, data for Hyloscirtus and for 15 species of Boana. Most species showed karyotypes with 2n = 2x = 24 chromosomes; some species of the B. albopunctata group have 2n = 2x = 22, and H. alytolylax has 2n = 2x = 20. Karyotypes are all bi-armed in most species presented, with the exception of H. larinopygion (FN = 46) and H. alytolylax (FN = 38), with karyotypes that have a single pair of small telocentric chromosomes. In most species of Boana, NORs are observed in a single pair of chromosomes, mostly in the small chromosomes, although in some species of the B. albopunctata, B. pulchella, and B. semilineata groups, this marker occurs on the larger pairs 8, 1, and 7, respectively. In Hyloscirtus, NOR position differs in the three studied species: H. alytolylax (4p), H. palmeri (4q), and H. larinopygion (1p). Heterochromatin is a variable marker that could provide valuable evidence, but it would be necesserary to understand the molecular composition of the C-bands that are observed in different species in order to test its putative homology. In H. alytolylax, a centromeric DAPI+ band was observed on one homologue of chromosome pair 2. The band was present in males but absent in females, providing evidence for an XX/XY sex determining system in this species. We review and discuss the importance of the different chromosome markers (NOR position, C-bands, and DAPI/CMA3 patterns) for their impact on the taxonomy and karyotype evolution in Cophomantini

Effect of Fibrin Glue on the Biomechanical Properties of Human Descemet's Membrane

10.1371/journal.pone.0037456PLoS ONE75

Notion de transition vitreuse appliquée au séchage par pulvérisation de solutions glucidiques

National audienc

Application of (lamellar) keratoplasty and limbal stem cell transplantation for corneal clouding in the mucopolysaccharidoses - a review

Corneal clouding or opacification is a prominent feature of mucopolysaccharidosis (MPS), particularly in MPS I and VI. In patients with marked corneal clouding and visual impairment, penetrating keratoplasty may be considered to improve the patient's vision, functional capacity and quality of life. In MPS, glycosaminoglycans mainly accumulate in the corneal stroma and not in Descemet's membrane or the endothelium, therefore deep anterior lamellar keratoplasty (DALK) may be preferred in these patients over penetrating keratoplasty. Although there are only limited data on the use of DALK in MPS (I and VI) patients, the results are generally favourable. Nonetheless, when deciding on whether to perform keratoplasty in patients with MPS, the risk of general anaesthesia due to potential concomitant cardio-pulmonary problems and cervical spine instability, the potential presence of other ocular manifestations that also impair vision (e.g. glaucoma, retinal degeneration and optic atrophy) and/or complications such as allograft rejection and the risk of re-opacification of the graft, all need to be taken into consideration. Limbal stem cell transplantation, which can be combined with keratoplasty, also holds potential promise in the treatment of these complex cases. A review of the indications, local and systemic risks, techniques of lamellar andpenetrating keratoplasty, and the potential of limbal stem cell transplantation is provided in the context of corneal opacity in MPS

Three-Year Outcomes of Tri-Folded Endothelium-In Descemet Membrane Endothelial Keratoplasty With Pull-Through Technique

Purpose: To assess the 3-year outcomes of tri-folded endothelium-in Descemet membrane endothelial keratoplasty (DMEK) using bimanual pull-through delivery technique. Design: Interventional case series. Methods: In this single-center study, we included 153 consecutive eyes that underwent DMEK for various indications (Fuchs endothelial corneal dystrophy [FECD]: n = 111; bullous keratopathy [BK]: n = 24; and failed graft: n = 18). DMEK grafts were loaded into a disposable cartridge in a tri-folded, endothelium-in configuration and delivered using bimanual pull-through technique. Main outcome measures were graft preparation and unfolding times, best spectacle-corrected visual acuity (BSCVA), endothelial cell density (ECD), and graft survival. Results: Mean graft preparation time was 5.9 ± 1.1 minutes; and mean graft unfolding time was 2.9 ± 0.9 minutes. Excluding eyes with comorbidities, logarithm of minimum angle of resolution BSCVA improved significantly from baseline preoperative values of 0.92 ± 0.58 to 0.02 ± 0.07 at 1 year (P < .001) and remained stable up to 3 years. Mean postoperative ECD decreased significantly (P < .001) from eye bank values to 1,818 ± 362, 1,675 ± 372, and 1,580 ± 423 cells/mm2 at 1, 2, and 3 years, respectively. No significant differences in ECD were observed between eyes with FECD and BK, but ECD was significantly lower in eyes with previous failed graft (P < .05). Three-year cumulative graft survival rate was significantly (P < .001) lower for eyes with previous failed graft (71%) than for FECD (97%) and BK (92%). Conclusions: Tri-folded endothelium-in DMEK requires minimal time for graft unfolding, which is the surgical step considered most challenging by corneal surgeons. Visual outcomes and complication rates are not adversely affected by the modification of the surgical technique

Bibliometric Analysis of Ophthalmology Publications from Arab Countries between 2012 and 2022

PURPOSE: The purpose of this study was to conduct a bibliometric analysis of articles published in Ophthalmology Journals from Arab countries from 2012 to 2022. METHODS: This cross-sectional analysis of all original ophthalmology research and review articles published by authors with an affiliation with an institution from Arab countries and indexed in the ISI Web of Science between January 2012 and December 2022. RESULTS: For the years 2012-2022, 4292 articles published in Ophthalmology Journals by authors from Arab-based institutions were identified. A 2.11-fold progressive increase in the number of publications was observed over the last decade with a substantial increase in publication volume during the first 2 years of the COVID-19 pandemic. The countries with the highest number of publications were Egypt (38.51%), Saudi Arabia (35.56%), and the United Arab Emirates (7.88%). According to affiliation, authors from King Khaled Eye Specialist Hospital (KKESH) (n = 644) published the highest number of ophthalmology articles, followed by King Saud University (n = 585) and Cairo University (n = 393). CONCLUSION: Over the last decade, the overall productivity of research in the field of ophthalmology has significantly increased. Majority of the articles in ophthalmology were published by authors from Egypt and Saudi Arabia with KKESH as the most productive institution among Arab nations

Effect of hinged lamellar keratotomy on postkeratoplasty eyes.

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