Comparative clinical trial of intracameral ropivacaine vs. lignocaine in subjects undergoing phacoemulsification under augmented topical anesthesia

Topical and subconjunctival anesthesia versus topical anesthesia alone in patients with senile cataracts undergoing phacoemulsification: a double-blind randomized controlled trial

BACKGROUND

This study compared topical anesthesia to a combination of topical anesthesia and subconjunctival anesthesia for phacoemulsification.

METHODS

This double-blinded parallel placebo-controlled randomized trial involved senile cataract patients scheduled for phacoemulsification between May and December 2022. Patients were randomly assigned to receive either topical anesthesia with 0.5% tetracaine hydrochloride and subconjunctival balanced salt solution injection (Control group) or topical anesthesia and subconjunctival injection with 2% lidocaine (Lidocaine group). Baseline parameters, cataract grades, and various outcomes were recorded, including pain scores at specific time points, patient cooperation scores, requests for additional anesthesia, and complications. Statistical methods included Fisher's exact test, the t-test, ordinal logistic regression, and linear regression with robust standard errors.

RESULTS

In total, 176 patients were included in the study after excluding 33 patients. A significant reduction in immediate postoperative pain was achieved in the Lidocaine group (p < 0.001) and was maintained for 2 h (p = 0.011). Additionally, better cooperation was observed in this group (p = 0.038). However, patients in the Lidocaine group experienced more pain during the subconjunctival injection (p = 0.001) and a significant increase in subconjunctival hemorrhage related to the injection (p < 0.001). Despite this, the rates of surgical complications were comparable between the groups, and all phacoemulsification procedures were successfully completed using the assigned anesthetic technique.

CONCLUSIONS

The addition of subconjunctival lidocaine injection to topical anesthesia reduced postoperative pain and improved patient cooperation during phacoemulsification. However, the lidocaine injection was painful, and it carried a higher risk of spontaneous-relief subconjunctival hemorrhage.

TRIAL REGISTRATION

Trial Registration Number: TCTR20220804003, date of registration August 4, 2022, retrospectively registered.

Intracameral Drug Delivery: A Review of Agents, Indications, and Outcomes

An intracameral (IC) injection directly delivers the drug into the anterior chamber of the eye. This targeted drug delivery technique overcomes the ocular barriers and offers a high therapeutic concentration of medication at the desired site and consequently better clinical outcomes. IC drug delivery is a safe and effective modality with many advantages over topical delivery. These include excellent bioavailability, reduced systemic risk, and minimal ocular toxicity. Agents delivered via IC injection have shown promising results against infection, inflammation, ocular hypertension, and neovascularization. Current literature shows that IC antibiotics, including cefuroxime, vancomycin, and moxifloxacin, are routinely used for prophylaxis of endophthalmitis. Other drugs available for IC use are steroids, anesthetics, mydriatics, miotics, antivascular endothelial growth factor, antiglaucoma, and alkylating agents. Introduction of sustained-release devices containing dexamethasone or Bimatoprost in anterior chamber via IC route has the potential in treating ocular inflammation and raised intraocular pressure. The complications such as hemorrhagic occlusive retinal vasculitis and toxic anterior segment syndrome have been documented with IC prophylaxis but are rare. In this review, we provide an overview of available IC drugs, their pharmacokinetics, the spectrum of activity, dosage and preparation, prophylactic and therapeutic usage, clinical efficacy, and safety profiles.

Comparing Efficacy and Safety of Intracameral Injection of Marcaine and Lidocaine on Postoperative Pain and Recovery After Cataract Surgery

Background: Various topical (intracameral) analgesics are used to relieve postoperative pain after cataract surgery. Objectives: We decided to compare the effects of intracameral Marcaine and lidocaine on pain intensity after the cataract operation. Methods: In this double-blind, randomized clinical trial, 64 patients who were candidates for cataract surgery were randomly assigned to either anesthesia with lidocaine or bupivacaine (Marcaine) by intracameral injection. Study endpoints included pain score, hemodynamic status, patient satisfaction, and recovery duration. Results: The Marcaine group experienced a shorter recovery than another group (P = 0.001). The mean pain score at the different time points after the operation was significantly lower in the group receiving Marcaine than those receiving lidocaine (P < 0.001). Our study showed a higher level of patients’ satisfaction with Marcaine as compared to the lidocaine group (P = 0.026). However, postoperative hemodynamic status was similar in both groups. Conclusions: Compared with lidocaine, intracameral injection of Marcaine results in a shorter postoperative recovery period, reduced pain intensity, and higher satisfaction among patients after cataract surgery.

Pharmacologic interventions for mydriasis in cataract surgery

BACKGROUND

Cataract surgery is one of the most common surgical procedures performed worldwide. Achieving appropriate intraoperative mydriasis is one of the critical factors associated with the safety and performance of the surgery. Inadequate pupillary dilation or constriction of the pupil during cataract surgery can impair the surgeon's field of view and make it difficult to maneuver instruments.

OBJECTIVES

To evaluate the relative effectiveness of achieving pupillary dilation during phacoemulsification for cataract extraction using three methods of pupillary dilation: topical mydriatics, intracameral mydriatics, or depot delivery systems. We also planned to document and compare the risk of intraoperative and postoperative complications following phacoemulsification for cataract extraction, as well as the cost-effectiveness of these methods for pupillary dilation.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), which contains the Cochrane Eyes and Vision Trials Register) (2021, Issue 1); Ovid MEDLINE; Embase.com; PubMed; Latin American and Caribbean Health Sciences Literature Database (LILACS); ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not use any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 22 January 2021.

SELECTION CRITERIA

We included only randomized controlled trial (RCTs) in which participants underwent phacoemulsification for cataract extraction.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodology.

MAIN RESULTS

We included a total of 14 RCTs (1670 eyes of 1652 participants) in this review. Of the 14 trials, 7 compared topical versus intracameral mydriatics, 6 compared topical mydriatics versus depot delivery systems, and 1 compared all three methods. We were unable to calculate overall estimates of comparative effectiveness for most outcomes due to statistical heterogeneity among the estimates from individual studies or because outcome data were available from only a single study. Furthermore, the certainty of evidence for most outcomes was low or very low, due primarily to imprecision and risk of bias. Comparison 1: topical mydriatics versus intracameral mydriatics Four RCTs (739 participants, 757 eyes) of the 8 RCTs that had compared these two methods reported mean pupillary diameters at the time surgeons had performed capsulorhexis; all favored topical mydriatics, but heterogeneity was high (I2 = 95%). After omitting 1 RCT that used a paired-eyes design, evidence from three RCTs (721 participants and eyes) suggests that mean pupil diameter at the time of capsulorhexis may be greater with topical mydriatics than with intracameral mydriatics, but the evidence is of low certainty (mean difference 1.06 mm, 95% confidence interval (CI) 0.81 mm to 1.31 mm; I2 = 49%). Four RCTs (224 participants, 242 eyes) reported mean pupillary diameter at the beginning of cataract surgery; the effect estimates from all trials favored topical mydriatics, with very low-certainty evidence. Five RCTs (799 participants, 817 eyes) reported mean pupillary diameter at the end of cataract surgery. Data for this outcome from the largest RCT (549 participants and eyes) provided evidence of a small difference in favor of intracameral mydriasis. On the other hand, 2 small RCTs (78 participants, 96 eyes) favored topical mydriatics, and the remaining 2 RCTs (172 participants) found no meaningful difference between the two methods, with very low-certainty evidence. Five RCTs (799 participants, 817 eyes) reported total intraoperative surgical time. The largest RCT (549 participants and eyes) reported decreased total intraoperative time with intracameral mydriatics, whereas 1 RCT (18 participants, 36 eyes) favored topical mydriatics, and the remaining 3 RCTs (232 participants) found no difference between the two methods, with very low-certainty evidence. Comparison 2: topical mydriatics versus depot delivery systems Of the 7 RCTs that compared these two methods, none reported mean pupillary diameter at the time surgeons performed capsulorhexis. Six RCTs (434 participants) reported mean pupillary diameter at the beginning of cataract surgery. After omitting 1 RCT suspected to be responsible for high heterogeneity (I2 = 80%), meta-analysis of the other 5 RCTs (324 participants and eyes) found no evidence of a meaningful difference between the two methods, with very low-certainty evidence. Three RCTs (210 participants) reported mean pupillary diameter at the end of cataract surgery, with high heterogeneity among effect estimates for this outcome. Estimates of mean differences and confidence intervals from these three RCTs were consistent with no difference between the two methods. A fourth RCT reported only means for this outcome, with low-certainty evidence. Two small RCTs (118 participants) reported total intraoperative time. Surgical times were lower when depot delivery was used, but the confidence interval estimated from one trial was consistent with no difference, and only mean times were reported from the other trial, with very low-certainty evidence. Comparison 3: Intracameral mydriatics versus depot delivery systems Only one RCT (60 participants) compared intracameral mydriatics versus depot delivery system. Mean pupillary diameter at the time the surgeon performed capsulorhexis, phacoemulsification time, and cost outcomes were not reported. Mean pupil diameter at the beginning and end of cataract surgery favored the depot delivery system, with very low-certainty evidence. Adverse events Evidence from one RCT (555 participants and eyes) comparing topical mydriatics versus intracameral mydriatics suggests that ocular discomfort may be greater with topical mydriatics than with intracameral mydriatics at one week (risk ratio (RR) 10.57, 95% CI 1.37 to 81.34) and one month (RR 2.51, 95% CI 1.36 to 4.65) after cataract surgery, with moderate-certainty evidence at both time points. Another RCT (30 participants) reported iris-related complications in 11 participants in the intracameral mydriatics group versus no complications in the depot delivery system group, with very low-certainty evidence. Cardiovascular related adverse events were rarely mentioned.

AUTHORS' CONCLUSIONS

Data from 14 completed RCTs were inadequate to establish the superiority of any of three methods to achieve mydriasis for cataract surgery, based on pupillary dilation at different times during the surgery or on time required for surgery. Only one trial had a sample size adequate to yield a robust effect estimate. Larger, well-designed trials are needed to provide robust estimates for the comparison of mydriasis approaches for beneficial and adverse effects.