Effects of Pranoprofen on Aqueous Humor Monocyte Chemoattractant Protein-1 Level and Pain Relief During Second-Eye Cataract Surgery

Pain perception enhancement in consecutive second-eye phacoemulsification cataract surgeries under topical anesthesia

Cataract is the main cause of visual impairment and blindness worldwide while the only effective cure for cataract is still surgery. Consecutive phacoemulsification under topical anesthesia has been the routine procedure for cataract surgery. However, patients often grumbled that they felt more painful during the second-eye surgery compared to the first-eye surgery. The intraoperative pain experience has negative influence on satisfaction and willingness for second-eye cataract surgery of patients with bilateral cataracts. Intraoperative ocular pain is a complicated process induced by the nociceptors activation in the peripheral nervous system. Immunological, neuropsychological, and pharmacological factors work together in the enhancement of intraoperative pain. Accumulating published literatures have focused on the pain enhancement during the second-eye phacoemulsification surgeries. In this review, we searched PubMed database for articles associated with pain perception differences between consecutive cataract surgeries published up to Feb. 1, 2024. We summarized the recent research progress in mechanisms and interventions for pain perception enhancement in consecutive second-eye phacoemulsification cataract surgeries. This review aimed to provide novel insights into strategies for improving patients' intraoperative experience in second-eye cataract surgeries.

Can lubrication of the eyelid speculum reduce overall pain perception associated with cataract surgery by phacoemulsification performed under topical anesthesia?

Purpose

This study aimed to evaluate the effect of using the lubricated eyelid speculum on the overall pain perception by the subject patients who underwent cataract surgery by phacoemulsification technique under topical anesthesia.

Methods

A prospective interventional randomized comparative study was conducted at the tertiary eye care center, wherein adult patients scheduled for bilateral cataract surgery with phacoemulsification techniques under topical anesthesia were randomized to undergo surgery with two different modes of eyelid speculum insertion, either with or without lubrication of the eyelid speculum. Fifty percent of the patients underwent surgery with eyelid speculum without lubrication, and 50% with lubrication of the eyelid speculum. The primary outcome was to compare the level of overall pain perception among the subject patients of the two groups by using the Visual Analogue Scale (VAS) in the immediate postoperative period.

Results

The study included 130 patients who underwent bilateral cataract surgery (n = 260 eyes) under topical anesthesia, wherein n = 130 eyes underwent surgery using lubricated eyelid speculum and n = 130 eyes underwent surgery with dry eyelid speculum. Pain perception score assessed on the VAS (0-10 cm) ranged from 0.5 to 6, with a mean ± standard deviation of 2.06 ± 1.12. A significant correlation was found with two different methods of eyelid speculum insertion with reduced overall pain perception in patients with the use of lubricated eyelid speculum compared to the dry eyelid speculum (P = 0.0001).

Conclusion

The overall pain perception associated with cataract surgery performed by phacoemulsification technique under topical anesthesia can be further minimized by lubricating the eyelid speculum prior to insertion for exposing the globe.

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

The aim of this study was to explore the correlation between intraoperative hyperalgesia of the second eye and the dynamic changes of tumor necrosis factor (TNF)-α and interleukin (IL)-1β levels in aqueous humor (AH) of the second eye and whole blood after the first eye cataract surgery. A rabbit model of monocular phacoemulsification was established by administration of 0.3% levofloxacin. Whole blood and AH samples from non-surgical eyes in the experimental group (n =25) and second eye in the blank control group (n =15) were obtained and corneal sensitivity was examined after surgery (1, 3, 7, 14, and 21 days postoperatively). TNF-α and IL-1β levels in AH and TNF-α mRNA and IL-1β mRNA levels in whole blood were measured. In a clinical study, 30 patients who underwent bilateral phacoemulsification within 1 month were divided into six groups in accordance with the operation intervals (1, 3, 7, 10, 14, and 21days). TNF-α and IL-1β levels in AH were measured at the beginning of surgery and intraoperative pain was assessed immediately after surgery. Corneal sensitivity (F =244.910, P <0.05), TNF-α and IL-1β levels in AH (F =184.200, 82.900, P <0.05) of non-surgical eyes and in whole blood (F =272.800, 193.530, P <0.05) in the experimental group were significantly higher than the baseline levels after phacoemulsification. In the clinical study, NRS scores of second eye surgery were higher than those of the first eye(P =0.0025) and 19 (63.3%) patients reported more pain during the second eye surgery. TNF-α and IL-1β concentrations in AH of the second eye were significantly higher than those of the first eye (F =123.60, P <0.05; F =59.60, P <0.05). In conclusion, within 1 month after the first eye phacoemulsification, higher pain sensitivity (hyperalgesia) exists in the second eye, which may be related to dynamic changes in TNF-α, IL-1β levels in AH or whole blood.

Dynamic monocyte chemoattractant protein-1 level as predictors of perceived pain during first and second phacoemulsification eye surgeries in patients with bilateral cataract

Background

The purpose of the study was to investigate whether dynamic monocyte chemoattractant protein-1 (MCP-1) level might be as predictors of perceived pain during the first and second phacoemulsification eye surgeries in patients with bilateral cataract.

Methods

Consecutive bilateral cataract patients undergoing bilateral sequential phacoemulsification were retrospectively enrolled. Patients’ preoperative anxiety score and intraoperative pain score were registered. Aqueous humor samples were obtained during surgery. MCP-1 level in the aqueous humor was measured by enzyme linked immunosorbent assay (Elisa). Patients were assigned to seven subgroups based on the interval between first-eye and second-eye cataract surgery. Comparisons were performed for a subjective sensation and MCP-1 levels among different subgroups.

Results

pain score during second-eye surgery was significantly higher than during first-eye surgery. Whereas there was no statistical difference in anxiety score between both surgeries. Result from subgroups comparison showed that the visual analog scale (VAS) pain score was statistically greater in 1-group and 6-group during the second eye surgery. Anxiety score did not statistically differ in subgroups. Additionally, the second-eye MCP-1 level was significantly higher at week 1and 6 intervals. Preoperative MCP-1 level was positively correlated with perceiving pain score during both surgeries.

Conclusions

MCP-1 level in aqueous humor significantly correlated with perceived pain during cataract surgery. Dynamic MCP-1 level could function as predictors of perceived pain during the first and second phacoemulsification eye surgeries in patients with bilateral cataract, which might support clinicians in treatment optimization and clinical decision-making.

Intraoperative Pain Sensation During Cataract Surgery: Why Does Timing Matter?

Purpose: To investigate whether timing influences pain perception during cataract surgery and to investigate the possible mechanisms.Methods: Patients scheduled for cataract surgery both in the morning and afternoon were consecutively enrolled. Questionnaires to evaluate anxiety, including the Simplified State-Trait Anxiety Inventory, Amsterdam Preoperative Anxiety and Information Scale, and a visual analogue scale (VAS) for anxiety, were completed preoperatively, whereas a VAS for pain and the Wong-Baker FACES® Pain Rating Scale questionnaire were completed after surgery. Preoperative blood pressure and heart rate were recorded. Blood samples were acquired before surgery, and plasma cortisol, adrenocorticotropic hormone, adrenalin, and noradrenalin were tested.Results: Fifty-five patients underwent uneverntful cataract surgery (28 in the morning and 27 in the afternoon) were included in the final analysis. Greater intraoperative pain perception during cataract surgery was reported in the afternoon than in the morning. Overall anxiety levels were significantly higher in the afternoon. Plasma adrenalin levels were significantly higher in the afternoon. Cortisol levels were higher in the afternoon. Preoperative anxiety levels were closely related to intraoperative pain perception. Both adrenalin and cortisol correlated positively with preoperative anxiety, but only adrenalin correlated significantly with the pain scores.Conclusions: Patients undergoing cataract surgery in the afternoon showed more preoperative anxiety, which may have increased their relevant stress hormones. Both the patient's emotional state and hormone levels may together aggravate his/her perceived pain in the afternoon. Monitoring preoperative anxiety levels, blood pressure, and heart rate should help to identify patients at higher risk of perceived intraoperative pain.Clinical trial registration:Trial registration number: NCT02182921Registration site: clinicaltrials.gov.

Pranoprofen Nanoparticles With Poly(L-Lactide)-b-Poly(Ethylene Glycol)-b-Poly(L-Lactide) as the Matrix Toward Improving Ocular Anti-inflammation

Nanotechnology using biodegradable polymer carriers with good biocompatibility and bioabsorbability has been studied and applied extensively in drug delivery systems and biomedical engineering. In this work, the triblocked oligomer poly(L-lactide)-b-poly(ethylene glycol)-b-poly(L-lactide) (PLEL) with the molecular weight of 2.08 KDa was first synthesized. Its chemistry was characterized by hydrogen nuclear magnetic resonance (1H-NMR) spectrum and Fourier transform infrared (FTIR) spectroscopy. Subsequently, the nanoparticles (NPs) of PLEL and pranoprofen (PF)-loaded PLEL were prepared with the average particle size of (151.7 ± 5.87) nm using the method of emulsion solvent evaporation. The formula and drug releasing profile were characterized by a transmission electron microscope (TEM), dynamic light scattering (DLS), and ultraviolet spectrophotometer (US). In vitro cytotoxicity assays and in vivo ophthalmic tests were performed to measure the safety and efficacy of the formulations. The results showed that PF NPs relieved the cytotoxicity of pure PF and eliminated ophthalmic irritation. The drug encapsulated in the nanoparticles displayed long-lasting release and good anti-inflammation efficiency in animal eyes. Therefore, we concluded that the present formula (PF NPs) could provide sustained drug release with good treatment effect on eye inflammation, and is promising for its use in ophthalmology in the future.

Substance P induces sympathetic immune response in the contralateral eye after the first eye cataract surgery in type 2 diabetic patients

Background

Substance P (SP) is a nociceptive tachykinin which regulates the immune inflammatory reactions including monocyte chemoattractant protein 1 (MCP-1) production. Sequential second-eye cataract surgery patients often suffer more pain than the first one partly because of the MCP-1 increase in aqueous humor (AH). This study aims to illustrate whether SP is involved in sympathetic inflammatory responses in the contralateral eye in patients with or without type 2 diabetes.

Methods

This prospective randomized clinical study included 51 cataract patients (22 with diabetes and 29 without). Bilateral sequential cataract surgeries were conducted with 1-day or 1-week interval randomly. More than 100 μl of AH were obtained before surgery and stored for later analysis using magnetic Luminex assays to detect interleukin (IL)-1β, IL-1ra,IL-6, IL-8, IL-10, MCP-1, vascular endothelial growth factor, spinal macrophage inflammatory protein (MIP-1a), interferon-inducible protein 10 (IP-10), regulated on activation, normal T expressed and secreted (RANTES), as well as the enzyme-linked immunosorbent assay for SP.

Results

Among the 4 groups, no significant differences were found in age, sex distribution, the R/L ration of the first surgery eye, or the lens nucleus hardness (P ≥ 0.802). Over 100 μl of AH samples were collected safely in all cases without intraoperative complications. SP and MCP-1 levels were both increased significantly in the second eye of the diabetic patients with 1-day and 1-week interval (P ≤ 0.040). The SP increase in the second eye of the diabetic patients were significantly higher than that of the patients without diabetes (P ≤ 0.030) both in the groups with 1-day and 1-week interval. Similarly, the MCP-1 increase was significantly higher in the diabetic patients in the group with 1-week interval (P = 0.042).

Conclusions

Substance P and MCP-1 productions elevated in the AH of the contralateral eye after the first-eye cataract surgery in diabetic patients, indicating that SP and MCP-1 were involved in the sympathetic inflammatory responses. Diabetic patients are susceptible to noninfectious inflammation after cataract surgery, and perceive more pain in the second-eye phacoemulsification.

Trial registration

Chinese Clinical Trial Registry, ChiCTR1900028374, retrospectively registered on 20th December, 2019.

Factors affecting pain in patients undergoing bilateral cataract surgery

PURPOSE

To compare the perceived pain and estimated operative duration among patients undergoing bilateral cataract surgery and to demonstrate correlations with the surgical interval and the demographic and medical characteristics of the patients.

METHODS

A total of 466 patients with cataract who underwent ocular surgery were included. The patients estimated the perceived operative duration and pain they felt during the operation at two times, immediately after surgery and on the first postoperative day; pain was scored using a visual analog scale ranging from 0 (no pain) to 10 (unbearable pain). Patients undergoing bilateral surgeries were divided into four subgroups based on the interval between the two operations (1, 2, 4, or 6 weeks). The perceived pain score and the estimated operative duration were the primary outcomes.

RESULTS

The pain scores were higher for the second surgery than for the first surgery both immediately after surgery (P = 0.043) and on the first postoperative day (P = 0.002). The estimated operative duration was longer for the second surgery (P = 0.001). Only patients who underwent the second surgery at an interval of 2 weeks perceived more pain both immediately and 1 day postoperatively (P = 0.002, P = 0.022) and a longer operative duration (P < 0.001). Gender, age, and education level might also influence the pain score.

CONCLUSIONS

Female patients, patients with a younger age, and patients with higher education level are likely to report more pain. Patients who require bilateral cataract surgery should not undergo the second surgery before an interval of 2 weeks.

Pain Perception of the First Eye versus the Second Eye during Phacoemulsification under Local Anesthesia for Patients Going through Cataract Surgery: A Systematic Review and Meta-Analysis

Background

Phacoemulsification under local anesthesia is regarded as the major surgery for cataract treatment. Recent research has compared the pain perception between the first eye and the second eye during phacoemulsification. However, these studies have also yielded controversial findings. Consequently, we performed a systematic review and a meta-analysis to investigate the difference in the pain perception between the first and second eyes during phacoemulsification.

Method

We searched the PubMed, EMBASE, and Cochrane CENTRAL databases for the studies published up to October 5, 2018. Prospective observational studies were included. The meta-analysis was conducted by means of random-effects model and fixed-effects model according to the heterogeneity. Evaluation of the methodological quality of studies was based on Newcastle-Ottawa Scale (NOS).

Results

Overall, eight studies were included in the meta-analysis. The analysis of pooled data showed that the pain scores of the first eye shortly after surgery under local anesthesia were significantly lower as compared to the second eye (WMD: 0.69; 95% CI: 0.40, 0.98; P < 0.00001). The average pain scores of the first eye shortly after surgery under the topical anesthesia were also lower than those of the second eye (WMD: 1.08; 95% CI: 0.79, 1.36; P < 0.00001). Conversely, anxiety scores in the first eye surgery were significantly higher than those in the second eye surgery (SMD: −0.40; 95% CI: −0.64, −0.16; P=0.001). However, the difference of the pain scores accessed on the first postoperative day between the first and second eye surgeries (WMD: −0.05; 95% CI −0.40, 0.31; P=0.79) as well as cooperation grades of patients between the first and second eye surgeries (WMD: 0.35; 95% CI −0.07, 0.76; P=0.10) was not statistically significant.

Conclusion

Patients experienced more pain in the surgery of the second eye than that of the first eye, which probably related to lower anxiety before the second surgery. It suggests that we should consider preoperative intervention to reduce the perceived pain during second eye cataract surgery.