Fluid dynamics of a novel micro-fistula implant for the surgical treatment of glaucoma,”

PURPOSE. The purpose of this study was to describe the fluidics of a novel non-valved glaucoma implant designed to prevent hypotony and compare the fluidics of this device with two commonly used non-valved glaucoma devices. METHODS. The XEN 45 micro-fistula implant was designed to limit hypotony by virtue of its length and width according to the Hagen-Poiseuille equation. Flow testing was performed using a syringe pump and pressure transducer at multiple flow rates. The pressure differentials across the XEN implant, the Ex-Press implant, and 10 mm of silicone tubing from a Baerveldt implant at a physiologic flow rate (2.5 lL/min) were extrapolated. RESULTS. The XEN 45 achieved a steady-state pressure calculated at 7.56 mm Hg at 2.5 lL/min. At the same flow rate, the Ex-Press device and Baerveldt tubing reached steady-state pressures of 0.09 and 0.01 mm Hg, respectively. CONCLUSIONS. Under flow testing, the XEN micro-fistula implant was able to maintain backpressure above numerical hypotony levels without the use of complex valve systems. This is due to the XEN implant's design, derived from the principles that dictate Newtonian fluids

Single administration of intracameral bimatoprost implant 10 µg in patients with open-angle glaucoma or ocular hypertension

INTRODUCTION: This study evaluated the intraocular pressure (IOP)-lowering efficacy and safety of a single intracameral administration of bimatoprost implant 10 µg in adults with open-angle glaucoma or ocular hypertension. METHODS: Two identically designed, randomized, 20-month, parallel-group, phase 3 clinical trials (one study eye/patient) compared three administrations of 10- or 15-µg bimatoprost implant (day 1, weeks 16 and 32) with twice-daily topical timolol maleate 0.5%. An open-label, 24-month, phase 1/2 clinical trial compared one or two implants administered in the study eye with once-daily topical bimatoprost 0.03% in the fellow eye. Separate analyses of the pooled phase 3 and phase 1/2 study datasets evaluated outcomes in the 10-µg bimatoprost implant and comparator treatment arms after a single implant administration, up to the time of implant re-administration or rescue with IOP-lowering medication. RESULTS: In the phase 3 studies, 10-µg bimatoprost implant single administration demonstrated IOP reductions (hour 0) of 4.9-7.0 mmHg through week 15 from a mean (standard deviation, SD) baseline IOP of 24.5 (2.6) mmHg (n = 374); IOP in the topical timolol BID group was reduced by 6.0-6.3 mmHg from a mean (SD) baseline IOP of 24.5 (2.6) mmHg (n = 373). In the phase 1/2 study (n = 21), median time to use of additional IOP-lowering treatment (Kaplan-Meier analysis) was 273 days (approximately 9 months), and 5 of 21 enrolled patients (23.8%) required no additional IOP-lowering treatment up to 24 months after single administration. In each study, after a single implant administration there were no reports of corneal edema, corneal endothelial cell loss, or corneal touch, and no patients had 20% or greater loss in corneal endothelial cell density. CONCLUSIONS: Bimatoprost implant single administration lowers IOP and has a favorable safety profile. Additional studies are needed to further evaluate the duration of effect and factors predicting long-term IOP lowering after a single implant administration. TRIAL REGISTRATION NUMBERS: ClinicalTrials.gov NCT02247804, NCT02250651, and NCT01157364

Long-term endothelial safety profile with iStent inject in patients with open-angle glaucoma

PURPOSE: To report 5-year postoperative safety data of iStent inject, including overall stability, endothelial cell density (ECD), and endothelial cell loss (ECL) in patients with mild-to-moderate primary open-angle glaucoma (POAG). DESIGN: 5-year follow-up safety study of the prospective, randomized, single-masked, concurrently controlled, multicenter iStent inject pivotal trial. METHODS: In this 5-year follow-up safety study of the 2-year iStent inject pivotal randomized controlled trial, patients receiving iStent inject placement and phacoemulsification or phacoemulsification alone were studied for the incidence of clinically relevant complications associated with iStent inject placement and stability. Corneal endothelial endpoints were mean change in ECD from screening and proportion of patients with \u3e30% ECL from screening, from analysis of central specular endothelial images by a central image analysis reading center at several time points through 60 months postoperatively. RESULTS: Of the 505 original randomized patients, 227 elected to participate (iStent inject and phacoemulsification group, n = 178; phacoemulsification-alone control group, n = 49). No specific device-related adverse events or complications were reported through month 60. No significant differences were observed in mean ECD, mean percentage change in ECD, or proportion of eyes with \u3e30% ECL between the iStent inject and control groups at any time point; mean percentage decrease in ECD at 60 months was 14.3% ± 13.4% in the iStent inject group and 14.8% ± 10.3% in the control group (P = .8112). The annualized rate of ECD change from 3 to 60 months was neither clinically nor statistically significant between groups. CONCLUSIONS: Implantation of iStent inject during phacoemulsification in patients with mild-to-moderate POAG did not produce any device-related complications or ECD safety concerns compared to phacoemulsification alone through 60 months

New devices in glaucoma

Glaucoma remains a leading cause of blindness globally. Minimally invasive treatment techniques are rapidly expanding the availability of therapeutic options for glaucoma. These include devices aimed at enhancing outflow through the subconjunctival space, Schlemm\u27s canal, and suprachoroidal space, sustained-release drug delivery devices, and extraocular devices aiming to reduce glaucomatous progression through other novel means. In this review, we provide an overview of several novel devices either newly available or in development for the medical and surgical management of glaucoma. Further studies are required to determine the long-term efficacy of these devices and how they will integrate into the current landscape of glaucoma management

Gestational Exposure to Sidestream (Secondhand) Cigarette Smoke Promotes Transgenerational Epigenetic Transmission of Exacerbated Allergic Asthma and Bronchopulmonary Dysplasia

Embryonic development is highly sensitive to xenobiotic toxicity and in utero exposure to environmental toxins affects physiological responses of the progeny. In the United States, the prevalence of allergic asthma (AA) is inexplicably rising and in utero exposure to cigarette smoke increases the risk of AA and bronchopulmonary dysplasia (BPD) in children and animal models. We reported that gestational exposure to sidestream cigarette smoke (SS), or secondhand smoke, promoted nicotinic acetylcholine receptor-dependent exacerbation of AA and BPD in mice. Recently, perinatal nicotine injections in rats were reported to induce peroxisome proliferator-activated receptor γ-dependent transgenerational transmission of asthma. Herein, we show that first generation and second generation progeny from gestationally SS-exposed mice exhibit exacerbated AA and BPD that is not dependent on the decrease in peroxisome proliferator-activated receptor γ levels. Lungs from these mice show strong eosinophilic infiltration, excessive Th2 polarization, marked airway hyperresponsiveness, alveolar simplification, decreased lung compliance, and decreased lung angiogenesis. At the molecular level, these changes are associated with increased RUNX3 expression, alveolar cell apoptosis, and the antiangiogenic factor GAX, and decreased expression of HIF-1α and proangiogenic factors NF-κB and VEGFR2 in the 7-d first generation and second generation lungs. Moreover, the lungs from these mice exhibit lower levels of microRNA (miR)-130a and increased levels of miR-16 and miR-221. These miRs regulate HIF-1α-regulated apoptotic, angiogenic, and immune pathways. Thus the intergenerational effects of gestational SS involve epigenetic regulation of HIF-1α through specific miRs contributing to increased incidence of AA and BPD in the progenies

Implantable MEMS drug delivery device for cancer radiation reduction

We present the first implantable MEMS drug delivery device that includes an electrochemical bellows pump, refillable drug reservoir, and dual regulation valve. Multiple drug pump configurations were fabricated, assembled, and tested. Delivery of agents for cancer radiation reduction was demonstrated. In vivo chronic delivery of radiation sensitizing agents in the form of small interfering (siRNA)-gold nanorod complexes (nanoplexes) directly to tumors induced in mice was achieved. Radiation therapy in conjunction with active drug pumping by electrolysis actuation resulted in significant reduction of colon cancer tumor (HT29) size (~50%) over diffusion-based delivery and intravenous injections. To our knowledge, this is the first MEMS drug delivery pump suitable for safe, efficacious, and local delivery of short half-life siRNA in vivo