Improved subjective symptoms of conjunctivochalasis using bipolar diathermy method for conjunctival shrinkage

Tomoyuki Kashima1,2, Hideo Akiyama1, Fumihide Miura2, Shoji Kishi11Department of Ophthalmology, Gunma University School of Medicine, Gunma, Japan; 2Department of Ophthalmology, Saku Central Hospital, Nagano, JapanPurpose: To evaluate the improvement in subjective symptoms of conjunctivochalasis after bipolar coagulation.Methods: Forty-three eyes of 26 patients (average age, 75.7 ± 8.4 years) were included in this study. The inferior conjunctivas were cauterized between April 2009 and June 2010. Surgery involved pinching the excess conjunctiva and performing bipolar cauterization after subconjunctival injection of a local anesthetic agent. Patients were asked to describe the postoperative foreign-body sensation and change in subjective symptoms 1 month postoperatively, with the preoperative symptom score defined as 10.Results: Twenty-two patients (84.6%) reported symptom relief immediately after the procedure, though all patients had a mild gritty sensation for 1–2 weeks postoperatively. The mean postoperative symptom score obtained from the questionnaire was 3.27 ± 3.31, which was significantly lower than the preoperative score (P < 0.0001). No patients had experienced recurrent symptoms at the end of the follow-up period.Conclusion: Thermal cauterization can achieve conjunctival shrinkage and adherence to the subconjunctival tissues. Operation time is only a few minutes, postoperative pain is not severe, and the procedure can be performed in an outpatient clinic, all of which represent benefits to the patients.Keywords: coagulation, cauterization, conjunctival injection&nbsp

Performance Evaluation of LoRa 920 MHz Frequency Band in a Hilly Forested Area

Long-range (LoRa) wireless communication technology has been widely used in many Internet-of-Things (IoT) applications in industry and academia. Radio wave propagation characteristics in forested areas are important to ensure communication quality in forest IoT applications. In this study, 920 MHz band propagation characteristics in forested areas and tree canopy openness were investigated in the Takakuma experimental forest in Kagoshima, Japan. The aim was to evaluate the performance of the LoRa 920 MHz band with spreading factor (SF12) in a forested hilly area. The received signal strength indicator (RSSI) was measured as a function of the distance between the transmitter antenna and ground station (GS). To illustrate the effect of canopy openness on radio wave propagation, sky view factor (SVF) and a forest canopy height model were considered at each location of a successfully received RSSI. A positive correlation was found between the RSSI and SVF. It was found that between the GS and transmitter antenna, if the canopy height is above 23 m, the signal diffracted and RSSI fell to −120 to −127 dBm, so the presence of the obstacle height should be considered. Further research is needed to clarify the detailed tree density between the transmitter and ground station to propose an optimal propagation model for a forested environment