Correlation between Hyperalgesia and Upregulation of TNF-α and IL-1β in Aqueous Humor and Blood in Second Eye Phacoemulsification: Clinical and Experimental Investigation

Antiarthritic and Antinociceptive Properties of Ylang-Ylang (Cananga odorata) Essential Oil in Experimental Models

The aim of this study was to evaluate the effect of ylang-ylang (Cananga odorata) essential oil (YEO) on models of experimental arthritis, persistent inflammation, and nociception in mice. YEO treatment at doses of 100 and 200 mg/kg reduced the infiltration of leukocytes into the joint cavities of mice submitted to zymosan-induced arthritis 6 h and 7 days after arthritis induction. At these doses, YEO treatment reduced the formation of joint edema 4 and 6 h after arthritis induction, and at a dose of 200 mg/kg, YEO treatment reduced mechanical hyperalgesia 3 and 4 h after arthritis induction. At the dose of 200 mg/kg, YEO treatment reduced interleukin-6 (IL-6) levels and cartilage destruction in the zymosan-induced arthritis model, and reduced edema formation and mechanical hyperalgesia in the model of persistent inflammation (21 days) induced by complete Freund's adjuvant (CFA) in mice. YEO treatment at a dose of 200 mg/kg reduced the nociceptive response in experimental models of nociception induced by acetic acid and formalin. The YEO treatment reduced inflammatory parameters in the experimental arthritis model, and presented antiarthritic, anti-hyperalgesic, antinociceptive, and anti-inflammatory properties.

Comparison of pain between bilateral ICL surgeries in patients with myopia

PURPOSE

The purpose of this study was to compare the preoperative anxiety, aqueous humor monocyte chemoattractant protein-1 (MCP-1) concentration, intraoperative pain, and degree of cooperation of the first eye implantable collamer lens (ICL) surgery with the second eye surgery, of the 1-day interval group with the 1-week interval group, and to investigate the possible causes of these differences, as well as to determine the appropriate interval between bilateral eye ICL surgeries.

METHOD

The study was a prospective observational study. A total of 120 patients who underwent bilateral ICL surgery at the Department of Ophthalmology, West China Fourth Hospital, Sichuan University, from July to September 2023, were enrolled. The patients were divided into a 1-day interval group and a 1-week interval group. The ICL surgery was performed on both eyes according to the schedule. Anxiety levels, aqueous humor MCP1, cooperativeness, surgical time, pain and satisfaction, and patients' estimations of the time spent in the operation were recorded for each eye. The patients were instructed to recall the intraoperative pain of the first eye surgery after the operation of the second eye. Statistical analyses (two independent samples t-test,two paired samples t-test, the rank-sum test, the chi-square test, non-parametric test with multiple independent samples) were performed to compare the differences between each score in both eyes and two groups. Furthermore, we examined the relationship between pain levels and the reproductive history of the patients.

RESULTS

In the 1-day interval group, male/female is 22/52, average age is 25.24±5.00. In the 1-week interval group, male/female is 17/29, average age is 25.39±5.57. There was no statistically significant difference between the two groups. In both groups, patients were less nervous, had significantly more pain, had less surgical satisfaction, had a longer estimated operative time, and had elevated preoperative MCP1 during the second eye operation. In the second eye surgery, the patient's cooperation worsened, but it did not lead to an increase in surgical time. A significant proportion of patients, particularly in the 1-week interval group, recalled experiencing reduced pain during the first eye surgery. The 1-week interval group had a higher difference in all indicators between the bilateral surgeries. In the second eye surgery, patients in the 1-week interval group experienced more severe pain, less cooperation, longer estimated operation duration, and a greater MCP1 than those in the 1-day interval group.

CONCLUSION

Patients undergoing second eye ICL surgery had decreased nervousness, increased pain, decreased cooperation, and satisfaction, and increased MCP1 compared to the first eye surgery. It is recommended that an interval of about one week should be avoided between bilateral surgeries when developing a surgical schedule to improve patients' cooperation, satisfaction, and comfort.

Gene expression changes in conjunctival cells associated with contact lens wear and discomfort

PURPOSE

This study aimed to analyze the differences in the expression of pain-related genes in conjunctival epithelial cells among symptomatic contact lens (CL) wearers (SCLWs), asymptomatic CL wearers (ACLWs), and non-CL wearers (non-CLWs).

METHODS

For this study, 60 participants (20 non-CLWs, 40 CLWs) were enrolled. The CLW group comprised 20 ACLWs and 20 SCLWs according to the Contact Lens Dry Eye Questionnaire short form©. Conjunctival cells were collected using impression cytology, and RNA was isolated and used to determine the expression levels of 85 human genes involved in neuropathic and inflammatory pain. The effects of CL wear and discomfort were evaluated using mixed-effects ANOVA with partially nested fixed-effects model. Gene set enrichment analysis was performed to assign biological meaning to sets of differentially expressed genes.

RESULTS

Six genes (CD200, EDN1, GRIN1, PTGS1, P2RX7, and TNF) were significantly upregulated in CLWs compared to non-CLWs. Eleven genes (ADORA1, BDKRB1, CACNA1B, DBH, GRIN1, GRM1, HTR1A, PDYN, PTGS1, P2RX3, and TNF) were downregulated in SCLWs compared to ACLWs. These genes were mainly related to pain, synaptic transmission and signaling, ion transport, calcium transport and concentration, and cell-cell signaling.

CONCLUSIONS

CL wear modified the expression of pain- and inflammation-related genes in conjunctival epithelial cells. These changes may be in part, along with other mechanisms, responsible for CL discomfort in SCLWs.