Intracameral lidocaine as supplement to classic topical anesthesia for relieving ocular pain in cataract surgery

Efficacy and safety of intraoperative use of tropicamide 0.02%/phenylephrine0.31%/lidocaine1% intracameral combination during pediatric cataract surgery

BACKGROUND

To demonstrate the safety and efficacy of the intracameral use of tropicamide 0.02%/phenylephrine 0.31%/lidocaine 1% in pediatric cataract surgery, a combination widely used in adult patients but still off-label in children.

METHODS

Design: two-center, prospective, observational study.

SETTING

San Giuseppe Hospital, Milan and Meyer Children's Hospital, Florence.

STUDY POPULATION

children from 0 to 4 years of age undergoing cataract surgery with or without intraocular IOL implantation, in the absence of clinically significant systemic conditions, history of ocular surgery, concurrent ocular medication, hypersensitivity to any of the substances and post-traumatic cataracts. During the surgery, patients received the combination drug after the primary access to the anterior chamber. Efficacy was evaluated by achieving an adequate mydriasis in order to perform capsulorhexis, while safety was assessed by recording vital signs (heart rate, blood pressure, respiratory rate, temperature) pre- and post-administration of the substance.

RESULTS

This study included 53 surgical procedures of 36 patients: 41 eyes were left aphakic, while 12 eyes received primary IOL implantation. The pupil size was adequate to safely perform capsulorhexis in 52 procedures of 53. The difference in pupil enlargement was significant (6.0 ± 1.14 mm, P =  < 0.001). There were no notable changes in vital parameters.

CONCLUSIONS

The administration of intracameral tropicamide 0.02%/phenylephrine 0.31%/lidocaine 1% in pediatric cataract surgery is effective for obtaining an adequate mydriasis without any vital parameters changes throughout the procedure.

Use of Simultaneous Bilateral Cataract Surgery (SBCS) to Optimize Parameters Affecting the Subjective Perception of the Procedure

Introduction

Simultaneous Bilateral Cataract Surgery (SBCS) is still a relatively controversial procedure. The main objection is the risk of bilateral endophthalmitis or bilateral refractive error. However, SBCS has also some advantages (faster visual rehabilitation, lower risk of nosocomial infection, and lower cost). Performing surgery on both eyes in one session has one additional advantage which has not yet been described in the literature (according to the information available to authors). It allows surgeons to distinguish the effect of minor differences in the surgical protocol on the subjective perception of the procedure more accurately, which is a more suitable method than comparing two independent groups of patients.

Purpose

To compare the effect of minor changes in the surgical protocol during SBCS on intraindividual subjective perception of surgery (pain, pressure, glare, and perception of the duration of the surgery).

Methods

During the surgery of the right and left eyes of one patient, we randomly changed one surgical parameter (use of intracameral anesthesia, light intensity of the operating microscope, type of eyelid speculum, creation of the posterior circular capsulorhexis, and communication with the patient during surgery). Patients immediately after both surgeries subjectively evaluated the perception of pain (on the scale 0–10), pressure, and glare (on the scale 0–5) and estimated the duration of the surgery, separately for each eye. Each change was evaluated in a group of 50 patients.

Results

In the control group with no parameters changed, we noted no difference in subjective perception of the first and second surgery. In subgroups, where we changed the protocol, we detected only minor differences in subjective perception of pain, pressure, glare, and duration of the surgery. Only one statistically significant difference in subjective pain perception was in the subgroup where we used eye intracameral anesthesia (0.34 eyes with intracameral anesthesia, 0.44 eyes with only topical anesthesia). We did not note any statistically significant differences in the perception of the time of surgery.

Conclusion

SBCS can be used to optimize the parameters of cataract surgery. In our study, we noted a positive effect of intracameral anesthesia on subjective perception of surgery.

Topical anaesthesia plus intracameral lidocaine versus topical anaesthesia alone for phacoemulsification cataract surgery in adults

BACKGROUND

Phacoemulsification cataract surgery is usually performed in adults under local anaesthesia. Topical anaesthesia, which involves instilling anaesthetic drops to the ocular surface prior to and during surgery, has found large acceptance internationally. It is safe and allows for rapid patient turnover and visual recovery. Some surgeons have supplemented topical anaesthesia with intracameral lidocaine, reasoning that this may further reduce intraoperative pain, particularly during surgical stages involving manipulation of intraocular structures and rapid changes in fluid dynamics. This review, originally published in 2006 and updated in 2020, explores the efficacy and safety of using supplementary intracameral lidocaine in phacoemulsification cataract surgery.

OBJECTIVES

To assess whether supplementing topical anaesthesia with intracameral lidocaine for phacoemulsification cataract surgery in adults reduces intraoperative and postoperative pain, and to assess differences in participant satisfaction, need for additional intraoperative anaesthesia, surgeon satisfaction, measures of intraocular toxicity, and adverse effects attributable to choice of anaesthesia.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, LILACS BIREME iAH, and six trial registries on 4 February 2020. We also searched the reference lists of identified studies. There were no language restrictions.

SELECTION CRITERIA

We included only randomized controlled trials (RCTs) where participants underwent phacoemulsification for age-related cataract under topical anaesthesia with or without intracameral lidocaine either in two eyes of the same participant, or in different participants. We also included studies that used oral or intravenous sedation in addition to local anaesthesia.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed trial methodological quality using standard Cochrane procedures.

MAIN RESULTS

We identified five new RCTs in this updated review. We included a total of 13 trials in the review, conducted in the UK, the USA, Australia, Italy, Canada, Taiwan, Singapore, India, and Pakistan, and comprising 2388 eyes of 2355 participants (one study was a paired-eye study with each participant acting as their own control). The age range of participants was 34 to 95 years. We excluded studies that only included low-risk participants and excluded more difficult operative cases, for example hard lens nuclei or small pupils. We excluded studies assessing only participants with Fuchs' endothelial dystrophy. We judged one study as at high risk for selection bias. We assessed five studies as having an unclear risk of bias for random sequence generation and seven studies an unclear risk of bias for allocation concealment. We judged three studies as at high risk of performance bias, as the surgeon was not blinded, and two studies as at unclear risk of bias for this domain. No studies were judged as at high risk for detection bias, but five studies were judged to have an unclear risk of bias for this domain. We judged all 13 included studies to have a low risk of attrition bias and an unclear risk of reporting bias. Data from eight RCTs favoured topical anaesthesia plus intracameral lidocaine 0.5% to 1% over topical anaesthesia alone for reducing intraoperative pain when measured using a 10-point visual analogue scale, analysed as a continuous outcome. Mean pain score was 0.26 lower in the supplemental intracameral lidocaine group (95% confidence interval (CI) -0.39 to -0.13, 1692 eyes, moderate-quality evidence). Data from seven RCTs favoured supplemental intracameral lidocaine for reducing intraoperative pain when measured as a dichotomous outcome. The odds ratio of experiencing any pain was 0.40 versus the topical anaesthesia-only group (95% CI 0.29 to 0.57, 1268 eyes, moderate-quality evidence). Data from four RCTs did not show any additional benefit on postoperative pain when measured using a 10-point visual analogue scale (mean difference 0.12 points, 95% CI -0.29 to 0.05, 751 eyes, moderate-quality evidence). The impact on participant satisfaction was uncertain as only one small study investigated this outcome. The study suggested no difference between groups (mean difference 0.1 points, 95% CI -0.47 to 0.27, 60 eyes, low-quality evidence). Data from seven RCTs did not demonstrate a difference between groups in the need for additional intraoperative anaesthesia (odds ratio 0.88, 95% CI 0.56 to 1.39, 1194 eyes of 1161 participants; low-quality evidence), although this result is uncertain. A variety of measures were reported relating to possible intraocular toxicity. Data from four RCTs did not demonstrate a difference between groups in mean percentage corneal endothelial cell count change from pre- to postoperatively (mean difference 0.89%, 95% CI -1.12% to 2.9%, 254 eyes of 221 participants, moderate-quality evidence). Synthesis of the evidence from eight RCTs identified no difference in intraoperative adverse events between groups (odds ratio 1.00, 95% CI 0.32 to 3.16, 1726 eyes, low-quality evidence). This result should be interpreted with caution, mainly due to a lack of clear definitions of adverse events, low numbers of events, heterogeneity between studies, and large confidence intervals. Large observational studies may have been more appropriate for looking at this outcome.

AUTHORS' CONCLUSIONS

There is moderate-quality evidence that supplementation of topical anaesthesia with intracameral lidocaine 0.5% to 1% for phacoemulsification cataract surgery in adults reduces participant perception of intraoperative pain. The odds of experiencing any pain (as opposed to no pain) were 60% less for the topical anaesthesia plus intracameral lidocaine group versus the topical anaesthesia-only group. However, the numerical amplitude of the effect may not be of great clinical significance on the continuous pain score scale. Generally, the pain scores were consistently low for both techniques. We found moderate-quality evidence that there is no additional benefit of intracameral lidocaine on postoperative pain. There is insufficient evidence to determine the impact on participant satisfaction and need for additional intraoperative anaesthesia due to low-quality evidence. There is moderate-quality evidence that intracameral lidocaine supplementation does not increase measures of intraocular toxicity, specifically loss of corneal endothelial cells. There is low-quality evidence that the incidence of intraoperative adverse events is unchanged with intracameral lidocaine supplementation, but as RCTs are not the optimum medium for looking at this, this result should be interpreted with caution. Further research specifically investigating the adverse effects of intracameral anaesthesia might help to better determine its safety profile. Economic evaluations would also be useful for detailing cost implications.