Safety and efficacy of topical anesthesia combined with a lower concentration of intracameral lidocaine in phacoemulsification

Intraoperative aberrometry in cataract surgery with topical versus peribulbar anesthesia

Purpose:

To study the effect of choice of anesthesia on the refractive outcomes of intraoperative aberrometry (IA) for intraocular lens power calculation in cataract surgeries.

Methods:

This prospective, interventional nonrandomized cohort study was conducted at a tertiary care hospital between March and August 2018. A total of 178 patients with age-related cataract were allocated into two groups. Group 1 received peribulbar anesthesia using a mixture of xylocaine 2% + adrenaline 0.125 mg/ml + hyaluronidase 15 IU/ml with a 23G, 32 mm needle, while Group 2 received topical anesthesia with proparacaine hydrochloride 0.05% drops. Intraoperative aphakic measurements and IOL power calculations were obtained in all patients with the optiwave refractive analysis (ORA) system. Analysis was performed to compare the baseline parameters and postoperative manifest refraction at month 1.

Results:

A total of 89 patients were included in group 1 and 89 in group 2. At baseline, the axial lengths (P = 0.66) and mean keratometry (P = 0.91) were comparable. The quality measure of captured wavefront data was comparable (0.25) between the groups. Also, the postoperative mean refractive spherical equivalents were comparable between the two groups (P = 0.98) at one month.

Conclusion:

IA can be utilized well for cataract surgeries performed under local anesthesia with good quality of captured wavefront, provided the eye can be aligned in centre with the fixation light of ORA.

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.

A comparison of patient pain and visual outcome using topical anesthesia versus regional anesthesia during cataract surgery

Purpose

The purpose of this study was to compare the level of patient pain during the phacoemulsification and implantation of foldable intraocular lenses while under topical, intracameral, or sub-Tenon lidocaine.

Patients and methods

This was a retrospective study. Three hundred and one eyes subjected to cataract surgery were included in this study. All eyes underwent phacoemulsification surgery and intraocular lens implantation using topical, sub-Tenon, or intracameral anesthesia. The topical group received 4% lidocaine drops, and the intracameral group received a 0.1–0.2 cc infusion of 1% preservative-free lidocaine into the anterior chamber through the side port combined with topical drops of lidocaine. The sub-Tenon group received 2% lidocaine. Best-corrected visual acuity, corneal endothelial cell loss, and intraoperative pain level were evaluated. Pain level was assessed on a visual analog scale (range 0–2).

Results

There were no significant differences in visual outcome and corneal endothelial cell loss between the three groups. The mean pain score in the sub-Tenon group was significantly lower than that in the topical and intracameral groups (P=0.0009 and P=0.0055, respectively). In 250 eyes without high myopia (< −6D), there were no significant differences in mean pain score between the sub-Tenon and intracameral groups (P=0.1417). No additional anesthesia was required in all groups.

Conclusion

Intracameral lidocaine provides sufficient pain suppressive effects in eyes without high myopia, while sub-Tenon anesthesia is better for cataract surgery in eyes with high myopia.

The effect of intracameral anesthesia on macular thickness and ganglion cell-inner plexiform layer thickness after uneventful phacoemulsification surgery: prospective and randomized controlled trial

BACKGROUND

To evaluate the effect of intracameral lidocaine anesthesia on macular thickness and macular ganglion cell-inner plexiform layer (GC-IPL) thickness following uneventful phacoemusification in healthy subjects.

METHODS

This is a prospective, randomized and double- masked study. One hundred eyes of 74 consecutive patients were randomized to receive intracameral preservative-free lidocaine 1 % (intracameral lidocaine group) or intracameral injection of balanced salt solution (sham injection group) at the time of the phacoemulsification surgery. Preoperative and postoperative macular thickness analyses with spectral domain optical coherence tomography (SD-ODT) were performed and the results between the two groups were compared.

RESULTS

Postoperatively, both the central foveal thickness (CFT) and the thickness of perifoveal macula were significantly improved in both groups (p < 0.001). There was no statistically significant difference between CFT and the inner and outer macular zone thicknesses of the two groups at any follow-up time. In both groups, GC-IPL thickness was significantly increased at the first week and first month visits (p < 0.001). There was no statistically significant difference between GC-IPL thickness measurements of the two groups at any follow-up time.

CONCLUSION

The current study demonstrated that supplementary intracameral lidocaine 1 % did not cause more macular thickening than the intracameral sham injection during a follow-up period of 3 months. The present study also showed a tendency for a transient increase in high definition SD-OCT-based GC-IPL thickness measurements within a few months following cataract surgery under both intracameral lidocaine anesthesia and intracameral sham injection.

Intracameral anesthesia for cataract surgery: a population-based study on patient satisfaction and outcome

Purpose

To evaluate if the standard anesthetic regimen – topical combined with intracameral anesthesia without sedation – in a population-based cohort of unselected cataract surgery cases is adequate, optimal, and good practice, or if improvements are necessary.

Methods

We conducted a prospective, observational study on all cases of cataract surgery during a 1-year period at one institution (n=1249). Data were collected from the patients’ records. Outcome measures were use of preoperative sedation, type of anesthesia, complications, and adverse events. In a subgroup of patients (n=124) satisfaction with the anesthetic regimen was evaluated using a short questionnaire.

Results

Most cases (90%, 1125/1249) had combined topical and intracameral anesthesia without sedation. Patients who chose preoperative sedation (midazolam hydrochloride sublingually) were significantly younger and more often female (P=0.0001 and P=0.011, respectively). In the questionnaire subgroup, the median pain score after surgery was 0.7 (visual analog scale, 0–10). A pain score of 1.9 or less was reported by 76% of the patients. Patients reporting a pain score of 2 or more had sedation and additional anesthetics more often. No significant difference was found regarding age, sex, pulse rate, oxygen saturation, first or second eye surgery, or adverse intraoperative events for patients with pain scores of 1.9 or less and 2 or more.

Conclusion

This large population-based series of small-incision phacoemulsification surgery shows that combined topical and intracameral anesthesia without sedatives is well tolerated for most phacoemulsification patients. It is also effective in cases when complications or adverse events occur. It is important to be responsive to the individual patient’s needs and adjust operating procedures if necessary, as there were a few patients who experienced insufficient anesthesia.