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Purpose: To report the surgical outcomes of antegrade balloon dacryocystoplasty combined with pushed-type monocanalicular intubation as a primary surgical treatment in patients with congenital nasolacrimal duct obstruction. Methods: A retrospective cohort study was conducted at National Cheng Kung University Hospital. The medical records of all patients with congenital nasolacrimal duct obstruction who underwent antegrade balloon dacryocystoplasty followed by pushed-type monocanalicular intubation as the primary surgical treatment from January 2018 to July 2020 were included. The monocanalicular tube was removed 1 to 2 weeks after intubation. Surgical success was defined as resolved epiphora 1 month after the tube was removed. Results: A total of 62 eyes of 48 patients were involved in this study. The mean age of the total population was 24.1 months (range: 12 to 66 months). The mean duration of the tube indwelling in the nasolacrimal duct was 9.5 days (range: 4 to 15 days). A total of 60 of the 62 eyes (96.77%) reported surgical success. Early tube loss occurred in 2 eyes (3.23%); however, epiphora was not reported afterward. No complications other than tube loss were recorded. There were no recurrences in patients who had undergone successful surgery observed up to July 2020. Conclusions: Antegrade balloon dacryocystoplasty with short-term pushed-type monocanalicular intubation as a primary surgical treatment for congenital nasolacrimal duct obstruction may have high potential with a high success rate and a low complication rate. [ J Pediatr Ophthalmol Strabismus . 2021;58(6):365–369.]

Given the improvement in the instrument and techniques, novel surgical interventions emerged to avoid the osteotomy from the gold standard dacryocystorhinostomy (DCR) for treating primary acquired nasolacrimal duct obstruction (PANDO). This study’s aim is to compare the surgical outcomes of antegrade balloon dacryocystoplasty (DCP) with pushed monocanalicular intubation (MCI) to balloon DCP alone in patients with complete PANDO. Adult patients with complete PANDO receiving balloon DCP followed by pushed MCI or balloon DCP alone from December 2014 to May 2019 were retrospectively reviewed. A total of 37 eyes of 29 patients were treated with balloon DCP with pushed MCI for 1 month, whereas 35 eyes of 28 patients were treated with balloon DCP alone. The success rates at 1 month, 3 months, and 6 months after operation were 89.2%, 73.0%, and 70.2%, respectively, in balloon DCP with MCI group, and 62.9%, 62.9%, and 60.0%, respectively, in the balloon DCP alone group. The balloon DCP with pushed MCI group had a better success rate but only reached statistical significance at 1 month postoperatively (p < 0.01). Subgroup analysis was performed based on age. The success rate in those under 65 in the combined balloon DCP with MCI group was significantly higher than in balloon DCP alone group (72.7% vs. 9.1%, p = 0.004), whereas there was no significant difference between those aged at least 65 in the combined group and the balloon DCP alone group (69.2% vs. 83.3%, p = 0.2). Conclusively, there was no significant difference in the success rate between antegrade balloon DCP with and without pushed MCI in general. Nevertheless, the former procedure was associated with significantly higher surgical success rate than the latter in younger patients.

Double circuit transmission line is an important part of the power grid, which is vulnerable to lightning and may endanger the security and stability of the power grid. In order to design a sensor which can monitor the lightning traveling wave current on double circuit transmission line, simulations of lightning on the double circuit transmission line were conducted. The simulation result shows that besides high frequency components, the traveling wave contains a lot of low frequency components. Based on the equivalent model and the frequency response of the self-integrated Rogowski coil, it turns out that the widely used self-integrated Rogowski coil is not suitable for this application as the problem of low frequency distortion. In this paper, through theoretical analysis and simulations in Matlab, an improved Rogowski coil with analog integrator is proposed which can correct the low frequency distortion of the self-integrated Rogowski coil. All the simulations, experiments and operating data installed to a double circuit transmission line in China verify the validity of the high bandwidth Rogowski coil.