Transcutaneous Electrical Stimulation for the Prevention of Dry Eye Disease after Photorefractive Keratectomy: Randomized Controlled Trial.

Objective: To evaluate the efficacy and safety of transcutaneous electrical stimulation (TES) for the prevention of dry eye after photorefractive keratectomy (PRK). Design: Prospective, single-center, single-blinded, parallel group, placebo-controlled, randomized clinical trial. Participants: Between February 2020 and October 2020, patients at the Samsung Medical Center scheduled to undergo PRK to correct myopia were screened and enrolled. Methods: The participants in the TES group were instructed to use the electrical stimulation device (Nu Eyne 01, Nu Eyne Co) at the periocular region after the operation, whereas those in the control group were to use the sham device. Dry eye symptoms were evaluated preoperatively and postoperatively at weeks 1, 4, and 12 using the Ocular Surface Disease Index (OSDI) questionnaire, the 5-Item Dry Eye Questionnaire (DEQ-5), and the Standard Patient Evaluation for Eye Dryness II (SPEED II) questionnaire. Dry eye signs were assessed using tear break-up time (TBUT), total corneal fluorescein staining (tCFS), and total conjunctival staining score according to the National Eye Institute/Industry scale. The pain intensity was evaluated using a visual analog scale. Main Outcome Measures: Primary outcomes were OSDI and TBUT. Results: Twenty-four patients were enrolled and completed follow-up until the end of the study (12 patients in the TES group, 12 patients in the control group). Refractive outcomes and visual acuity were not different between the groups. No serious adverse event was reported with regard to device use. No significant difference in OSDI and SPEED II questionnaires and the DEQ-5 was observed between the groups in the 12th week after surgery. The TBUT scores 12 weeks after the surgery were 9.28 ± 6.90 seconds in the TES group and 5.98 ± 2.55 seconds in the control group with significant difference (P = 0.042). The tCFS and total conjunctival staining score were significantly lower in the TES group than in the control group at postoperative 4 weeks. Pain intensity at the first week was significantly lower in the TES group than in the control group by 65% (P = 0.011). Conclusion: The application of TES is safe and effective in improving dry eye disease after PRK. Financial Disclosures: The author(s) have no proprietary or commercial interest in any materials discussed in this article.

The effect of charge-balanced transcutaneous electrical nerve stimulation on rodent facial nerve regeneration.

This study aimed to investigate the effect of charge-balanced transcutaneous electrical nerve stimulation (cb-TENS) in accelerating recovery of the facial function and nerve regeneration after facial nerve (FN) section in a rat model. The main trunk of the left FN was divided and immediately sutured just distal to the stylomastoid foramen in 66 Sprague-Dawley rats. The control group had no electrical stimulus. The other two groups received cb-TENS at 20 Hz (20 Hz group) or 40 Hz (40 Hz group). Cb-TENS was administered daily for seven days and then twice a week for three weeks thereafter. To assess the recovery of facial function, whisker movement was monitored for four weeks. Histopathological evaluation of nerve regeneration was performed using transmission electron microscopy (TEM) and confocal microscopy with immunofluorescence (IF) staining. In addition, the levels of various molecular biological markers that affect nerve regeneration were analyzed. Whisker movement in the cb-TENS groups showed faster and better recovery than the control group. The 40 Hz group showed significantly better movement at the first week after injury (p < 0.0125). In histopathological analyses using TEM, nerve axons and Schwann cells, which were destroyed immediately after the injury, recovered in all groups over time. However, the regeneration of the myelin sheath was remarkably rapid and thicker in the 20 Hz and 40 Hz groups than in the control group. Image analysis using IF staining showed that the expression levels of S100B and NF200 increased over time in all groups. Specifically, the expression of NF200 in the 20 Hz and 40 Hz groups increased markedly compared to the control group. The real-time polymerase chain reaction was performed on ten representative neurotrophic factors, and the levels of IL-1ß and IL-6 were significantly higher in the 20 and 40 Hz groups than in the control group (p < 0.015). Cb-TENS facilitated and accelerated FN recovery in the rat model, as it significantly reduced the recovery time for the whisker movement. The histopathological study and analysis of neurotrophic factors supported the role of cb-TENS in the enhanced regeneration of the FN.

Repellent activity of constituents identified in Foeniculum vulgare fruit against Aedes aegypti (Diptera: Culicidae).

The repellent activity of materials derived from the methanol extract of fruits from Foeniculum vulgareagainst hungry Aedes aegypti females was examined using skin and patch tests and compared with that of the commercial N,N-diethyl-m-toluamide (deet) and (Z)-9-octadecenoic acid. The biologically active constituents of the Foeniculum fruits were characterized as (+)-fenchone and (E)-9-octadecenoic acid by spectroscopic analyses. Responses varied according to compound, dose, and exposure time. In a skin test with female mosquitoes, at a dose of 0.4 mg/cm(2), (+)-fenchone and (Z)-9-octadecenoic acid exhibited moderate repellent activity at 30 min after treatment, whereas deet provided >1 h of protection against adult mosquitoes at 0.2 mg/cm(2). (Z)-9-Octadecenoic acid was a more potent repellent agent than (E)-9-octadecenoic acid. (+)-Fenchone and (E)-9-octadecenoic acid merit further study as potential mosquito repellent agents or as lead compounds.