Comparison of minimally invasive glaucoma surgery with trabecular micro-bypass stent and microhook ab interno trabeculotomy performed in conjunction with cataract surgery

AIM: To evaluate the effectuality and safety of cataract surgery combined with either ab interno trabeculotomy by the microhook(μLOT) or a single i Stent? trabecular bypass implantation(i Stent) in eyes with cataract and mild-tomoderate glaucoma. METHODS: This study enrolled subjects with mild-tomoderate open angle glaucoma with visually significant cataract who used two or more ophthalmic antiglaucoma agents between 60 and 90 y of age. Patients underwent cataract surgery cooperated with either implantation of an i Stent(i Stent-phaco) or excisional goniotomy with the μLOT(μLOT-phaco). Patients underwent μLOT-phaco in the eye with lower the mean deviation, according to the Humphrey field analyzer, while i Stent-phaco was carried out on the other eye. Intraocular pressure(IOP) pre-and post-surgery, alterations in anterior chamber flare(ACF), and corneal endothelial cell density(ECD) were estimated.RESULTS: Twenty subjects were enrolled(mean age: 73.6±7.3 y). The mean medicated preoperative IOP was 16.7 mm Hg in the μLOT and 16.2 mm Hg in the i Stent eyes. The mean final IOP at 12 mo was 13.6 mm Hg in the μLOT eyes and 13.6 mm Hg in the i Stent eyes, representing a 17.8% and 17.2% reduction, respectively. The preoperative ACF in the μLOT eyes was 9.5 pc/ms and it returned to normal in 30 d postoperatively, with a value of 11.4 pc/ms. In the i Stent eyes, ACF was 9.6 pc/ms preoperatively and it returned to normal by 7 d postoperatively(11.2 pc/ms atday 7), demonstrating that postoperative inflammation was less in the i Stent eyes. The corneal ECD in both groups was not significantly decreased.CONCLUSION: In this study, i Stent and μLOT are both effective through 12 mo of follow-up. Safety is more favorable in the i Stent eyes, based on early anterior chamber inflammation.

Global and Kinetic MHD Simulation by the Gpic-MHD Code

In order to implement large-scale and high-beta tokamak simulation, a new algorithm of the electromagnetic gyrokinetic PIC （particle-in-cell） code was proposed and installed on the Gpic-MHD code [Gyrokinetic PIC code for magnetohydrodynamic （MHD） simulation]. In the new algorithm, the vorticity equation and the generalized Ohm＇s law along the magnetic field are derived from the basic equations of the gyrokinetic Vlasov, Poisson, and Ampere system and are used to describe the spatio-temporal evolution of the field quantities of the electrostatic potential φ and the longitudinal component of the vector potential Az. The basic algorithm is equivalent to solving the reduced-MHD-type equations with kinetic corrections, in which MHD physics related to Alfven modes are well described. The estimation of perturbed electron pressure from particle dynamics is dominant, while the effects of other moments are negligible. Another advantage of the algorithm is that the longitudinal induced electric field, ETz = -δAz/δt, is explicitly estimated by the generalized Ohm＇s law and used in the equations of motion. Furthermore, the particle velocities along the magnetic field are used （vz-formulation） instead of generalized momentums （pz-formulation）, hence there is no problem of ＇cancellation＇, which would otherwise appear when Az is estimated from the Ampere＇s law in the pz-formulation. The successful simulation of the collisionless internal kink mode by the new Gpic-MHD with realistic values of the large-scale and high-beta tokamaks revealed the usefulness of the new algorithm.