Short—term Results of Using Lamellar Corneo—scleral Patch Graft for the Ahmed Glaucoma Valve Implant Surgery

Background: Human donor sclera is commonly used in glaucoma implant surgery to cover the external portion of the silicone tube and prevent its erosion through the overlying conjunctiva. Corneo-scleral graft is used in this study as an alternative material for its desirable properties of being transparent, higher in tensile strength, cheap and more readily available. Methods: Eighteen consecutive cases were implanted with the Ahmed glaucoma valve im-plant. The limbal portion of the silicone tube was covered by a comeo-scleral graft obtained from the corneo-scleral rim left over following corneal transplant operation. The effectiveness in protecting the tube from erosion or migration, the transparency of the patch graft and complications encountered after surgery were assessed.Results: At a mean follow-up of 6 months, all tubes were well protected and no complications related to the patch graft were encountered during intra and postoperative period. All comeo-scleral grafts remained transparent and health     

Effects of Y-27632, a Rho-associated Kinase Inhibitor,on Human Corneal Endothelial Cells Cultured by Isolating Human Corneal Endothelial Progenitor Cells

PurposeHuman corneal endothelial progenitor cells (HCEPs), which has been selectively isolated and differentiated into human corneal endothelial cells (HCECs), are crucial for repairing corneal endothelial damage. In this study, we evaluated the roles of a Rho-assisted kinase (ROCK) inhibitor, Y-27632, on the isolation and expansion of HCEPs, and assessed the in vitro effects of different concentrations of Y-27632 on the differentiated HCEPs.MethodsHCEPs were isolated and expanded in a medium with and without 10μM Y-27632, and then differentiated into HCECs in a medium with fetal bovine serum. The characteristics of HCEPs and differentiated HCEPs were confirmed by immunofluorescence staining. The proliferation, viability, morphology, and wound-healing ability of differentiated HCEPs were assessed in the presence of different concentrations of Y-27632.ResultsY-27632 enabled the isolation and expansion of HCEPs from the corneal endothelium. The differentiated HCEPs showed an optimal increase in proliferation and survival in the presence of 10μM Y-27632. As the concentration of Y-27632 increased, differentiated HCEPs became elongated, and actin filaments were redistributed to the periphery of cells. Y-27632 also caused a concentration-dependent enhancement in the wound-healing ability of differentiated HCEPs.ConclusionsY-27632 enabled the isolation and expansion of HCEPs. It also enhanced the proliferation, viability, and migration of differentiated HCEPs.     

Trabeculectomy with or without Anterior Chamber Maintainer: A Study on Intraocular Pressure,Endothelial Cells,and Central Corneal Thickness

Purpose: To compare the impact of trabeculectomy and trabeculectomy with an anterior chamber (AC) maintainer on intraocular pressure (IOP), endothelial cell density (ECD), and central corneal thickness (CCT) in patients with primary open angle glaucoma (POAG). Methods: The two groups consisted of 36 (trabeculectomy, Group A) and 42 (trabeculectomy with AC maintainer, Group B) patients with POAG. IOP, CCT, and ECD were measured one day prior to surgery, one month, six months, and 12 months postoperatively. Results: No complications were observed. The mean decrease of mean IOP from baseline to 12 months was statistically significant for both groups (all p < 0.0001), but more significant in Group B (p = 0.01). ECD decrease was significant in both Groups (all p < 0.01), but more significant in Group A (p < 0.0001). CCT decrease was also greater in Group A (p < 0.0001). The surgical procedure’s duration was significantly longer in Group B than in Group A (p < 0.0001). Conclusions: Both techniques seem to be effective and safe options for patients with POAG. Using an AC maintainer might add some safety for the ECD and a bit greater IOP reduction; however, the classic technique, which is of less complexity and less time-consuming, has comparable results.     

In-Vitro Effects of Dexamethasone on Cellular Proliferation,Apoptosis, and Na+-K+-ATPase Activity of Bovine Corneal Endothelial Cells

Purpose: To assess the in-vitro effects of dexamethasone (DEX) on the proliferation, apoptosis, and Na+-K+-ATPase activity of bovine corneal endothelial cells. Methods: Bovine corneal endothelial cells were cultured with DEX ranging from 10^?10 to 10^?3 M. The effect of DEX on the proliferation was analyzed by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxy-methoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt (MTS) assay. Apoptosis and necrosis were detected by staining with fluorescein-conjugated annexin V and propidium iodide, followed by flow cytometry. The effect of DEX on Na+-K+-ATPase activity was evaluated using non-isotopic methods. Results: DEX did not affect cellular proliferation or induce apoptosis/necrosis from 10^?10 to 10^?5 M. At 10^?4 and 10^?3 M, DEX significantly decreased proliferation and increased apoptosis and/or necrosis. DEX significantly increased the Na+-K+-ATPase activity from 10^?8 to 10^?6 M, with the maximal effect at 10^?6 M (p < 0.01); this effect was inhibited by RU38486, an antiglucocorticoid molecule. Conclusions: Bovine corneal endothelial cells express glucocorticoid receptor (GR) mRNA and protein. DEX decreases cell proliferation and induces cellular apoptosis and/or necrosis at high concentrations. DEX also increases the Na+-K+-ATPase activity at certain concentrations.     

Effect of Head Position and Tube Entry on Corneal Endothelial Cells in Patients with Glaucoma Drainage Implants: A Cross-sectional Study

PurposeTo investigate the effect of head tilt on the tube position of the Ahmed glaucoma valve (AGV) implanted in patients with glaucoma and to assess how the head tilt-induced alterations of tube parameters and the level of tube entry influence corneal endothelial cell density (ECD).MethodsA total of 29 eyes of 26 patients with AGV implantation were included. Tube-cornea distance, tube-cornea angle, and intracameral tube length were measured using anterior segment optical coherence tomography in three different head positions (neutral, 30° temporalward tilt, and 30° nasalward tilt). The tube entry was assessed using static gonioscopy. ECD was measured using specular microscopy before and after surgery.ResultsThe mean tube-cornea distance, tube-cornea angle, and intracameral tube length (neutral: 0.87 ± 0.39 mm, 30.56 ± 5.89˚, and 3.10 ± 0.82 mm, respectively) decreased with head tilts (temporalward: 0.82 ± 0.39 mm, 29.27 ± 5.82˚, and 3.04 ± 0.82 mm, respectively; nasalward: 0.83 ± 0.40 mm, 29.61 ± 6.04˚, and 3.05 ± 0.81 mm, respectively; all p < 0.01). The multivariate analyses found age and the tube insertion level to be associated with postoperative changes in the central ECD (p = 0.039 and 0.013, respectively), and the postoperative follow-up period and tube insertion level to be associated with the difference between the inferonasal and superotemporal ECDs (p = 0.034 and 0.007, respectively).ConclusionsMild alterations of head positions induced changes in the intracameral tube positions of AGV implants; nevertheless, it did not significantly affect ECD loss. However, the eyes with tubes inserted anteriorly to Schwalbe’s line may be more susceptible to corneal ECD loss.     

The Chemokine Receptor CCR7 Expressed by Dendritic Cells: A Key Player in Corneal and Ocular Surface Inflammation

Dendritic cells (DCs) are highly potent stimulators of the immune system, and their contribution as such to the pathogenesis of corneal and ocular surface inflammatory disease has been well established. These vigorous antigen-presenting cells are reliant upon their effective migration from peripheral tissues (e.g., those of the ocular surface) to the lymphoid organs, where immune responses are triggered and can then cause disease. The chemokine receptor CCR7 expressed on DCs has emerged as the master mediator of this highly complex migratory process, and thus it is important in causing corneal and ocular surface inflammation. Furthermore, CCR7 has received considerable attention as a potential therapeutic target, as topically instilled antagonists of this receptor are quite effective therapeutically in a mouse model of ocular allergy. These findings and more are reviewed in the current article. In addition, the understanding regarding CCR7 function in mice and humans, and the biology of DCs that populate the ocular surface are also detailed herein. The involvement of DCs and their expression of CCR7 in corneal and ocular surface diseases such as in ocular allergy, dry eye disease, immune rejection and more, are also reviewed here.