No-anesthesia clear corneal phacoemulsification versus topical and topical plus intracameral anesthesia. Randomized clinical trial

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.

Patient preference and pain-reported outcomes for topical versus subtenon anesthetic for cataract surgery

PURPOSE:

Cataract extraction and lens implantation is the most common surgical procedure performed worldwide, with surgeons opting for either a topical or a subtenon anesthetic in majority of cases. While complication rates and pain scores have been previously examined in a bid to determine which modality was better, patients who have had both eyes operated upon under different techniques have never previously been asked which method they prefer. We undertook this study to fill in this crucial gap in our knowledge.

METHODS:

This is a retrospective study of patients who have undergone bilateral cataract surgery with one eye operated on with topical anesthesia and the other eye with subtenon anesthesia. Patients were identified who had had surgery undertaken in the previous 6 months at Singleton Hospital, Swansea, where both eyes had been operated upon using different anesthetic techniques. Telephone interviews with these patients were performed and their pain scores recorded on a scale from 0 (no pain) to 10 (severe pain) for both eyes, with the patients then being asked which the method of anesthetic they preferred. Statistical analysis of pain scores was compared using Wilcoxon rank-sum testing.

RESULTS:

One hundred and fifty-two patients in total were identified. One hundred and forty-one of the applicable patients participated in the study. Of these, 78 patients received topical anesthesia for their first operation and 63 had subtenon block for their first operation. The mean pain scores reported for surgery with topical anesthesia and subtenon block were 2.30 and 1.38, respectively. The pain data were analyzed using a Wilcoxon signed-rank test, returning a z-score of 4.038. This result therefore suggests that patients experience statistically significantly less pain from cataract surgery when given a subtenon block. Patients expressed a preference for subtenon anesthesia, with 70% preferring subtenon block, 23% preferring topical anesthesia, and 7% having no preference.

CONCLUSIONS:

Patients report less pain with subtenon anesthesia compared with topical anesthesia in cataract surgery, where both eyes were operated upon with different anesthetic techniques. This is the first study in which patients who have had both anesthetic techniques performed independently for cataract surgery have had their pain scores reported and statistically analyzed.

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

Purpose:

To compare intracameral Ropivacaine to Lignocaine during phacoemulsification under augmented topical anesthesia, in terms of efficacy and safety.

Methods:

This prospective, randomized, double-masked clinical trial included subjects planned for phacoemulsification with posterior chamber intraocular lens implantation for visually significant uncomplicated senile cataract, under augmented topical anesthesia. Cases were randomized into two groups, Group A (Ropivacaine 0.1%) or Group B (Lignocaine 1.0%). The pain experienced by the patients during the surgery, mydriasis, post-op inflammation and endothelial cell change at six weeks after the procedure was evaluated. Surgeon's feedback was recorded to evaluate the cooperation of the patient during surgery.

Results:

A total of 210 subjects were screened and 184 were randomized to have 92 subjects in each group. There was no statistically significant difference seen on comparing Group A and B with respect to Age (P = 0.05), painful surgical steps (P = 0.85), visual analog scale scores (P = 0.65), surgeon's score (P = 0.11), postoperative inflammation (P = 0.90) and average ultrasound time during phacoemulsification (P = 0.10). Subjects in Group A fared better when compared to Group B with respect to endothelial cell loss (P = 0.0008), and augmentation in mydriasis (P < 0.001).

Conclusion:

Intracameral Ropivacaine and Lignocaine, both are equally effective in providing analgesia during phacoemulsification. However, intracameral Ropivacaine is superior to Lignocaine with regards to corneal endothelial cell safety, and augmenting mydriasis.

Development and Validation of a Questionnaire Assessing Patient Distress from Preoperative Fasting in Cataract Surgery

Purpose: To develop and psychometrically validate a questionnaire to measure patient distress with preoperative fasting related to cataract surgery.Methods: In this single-centered cross-sectional study, consecutive sampling of cataract patients was undertaken immediately preoperatively from February to December 2019. A questionnaire evaluating patient distress with fasting was designed and administered. Questionnaire development occurred in an iterative process and was conducted with consultation from expert investigators and patients. Validation and psychometric evaluation of the questionnaire were performed with Rasch analysis.Results: A preliminary version of the questionnaire was developed by 10 study investigators. Across five iterations of development, the questionnaire was administered to 186 cataract patients. Psychometric evaluation of the 13-item questionnaire demonstrated ordered thresholds, acceptable item calibration and fit, adequate internal consistency, ability to discriminate between three levels of distress from preoperative fasting and no notable differential item functioning. However, issues with mistargeting, clustering of items on the person-item map and multidimensionality remained. Given these concerns, 13 separate re-analyses were conducted via removal of certain items. A 6-item subset was determined to be well targeted, unidimensional, did not display item clustering and was able to discriminate between patients with high and low distress from preoperative fasting.Conclusion: A 6-item questionnaire is a valid, psychometrically robust and reliable measure for the assessment of patient distress with preoperative fasting in cataract surgery. Items include hunger, thirst, hoarseness, weakness, anxiety and nausea. Future studies should seek to validate this questionnaire across a variety of sociodemographic contexts, languages and specialties.

Perceived Surgeon Stress During No-Sedation Topical Phacoemulsification

Purpose

To determine the patient-related factors that contribute to surgeon stress during phacoemulsification cataract extraction (PCE) performed under unassisted topical anesthesia.

Methods

This is a prospective study of perceived surgeon stress during phacoemulsification by a single surgeon of consecutive patients undergoing PCE. At the conclusion of each procedure, the surgeon recorded the perceived stress according to the following three indices: surgeon score, qualitative score (yes or no), and total score (sum of itemized causes of stress). Patient variables included in the analysis included gender, age, diabetes mellitus, morbid obesity, intake of oral alpha blockers, floppy iris, laterality, pseudo-exfoliation, intraocular lens power, and initial visual acuity.

Results

During the 10-year study, 1097 eyes underwent surgery. The following patient variables were seen frequently: floppy iris syndrome (92), pseudo-exfoliation (72), and morbid obesity (36). Surgeon identified stress was reported after 250 procedures. On multivariable analysis, the following patient characteristics were associated with surgeon stress: age >80 years; morbid obesity; floppy iris syndrome; severe nuclear sclerosis; and poor baseline distance corrected visual acuity.

Conclusion

Several ocular and systemic patient-related characteristics contribute to surgeon stress during PCE.

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.

Preoperative fasting for ambulatory cataract surgery: asystematic review

Given the lack of policy standardization in Canada, this systematic review investigates the optimal duration of preoperative fasting in cataract surgery. A literature search was conducted on Ovid MEDLINE, with potential articles screened by 2 independent authors. The primary endpoint was the incidence of aspiration. Overall, 231 articles were screened, of which 6 were eligible. Two studies found no cases of aspiration in over 35 000 patients who underwent cataract surgery without preoperative fasting, some with intravenous sedation (50% in 1 series, less than 1% in the second). A survey of the British Ophthalmic Anaesthesia Society found that over 50% of centres did not require fasting before cataract surgery. Only 1 included report discussed a case of aspiration pneumonitis following cataract surgery with general anaesthesia and 14hours of preoperative fasting. In closing, further evidence is needed to delineate the risk of pulmonary aspiration based on fasting time in cataract surgery.

Sodium Ferulate Attenuates Lidocaine-Induced Corneal Endothelial Impairment

The introduction of intracameral anaesthesia by injection of lidocaine has become popular in cataract surgery for its inherent potency, rapid onset, tissue penetration, and efficiency. However, intracameral lidocaine causes corneal thickening, opacification, and corneal endothelial cell loss. Herein, we investigated the effects of lidocaine combined with sodium ferulate, an antioxidant with antiapoptotic and anti-inflammatory properties, on lidocaine-induced damage of corneal endothelia with in vitro experiment of morphological changes and cell viability of cultured human corneal endothelial cells and in vivo investigation of corneal endothelial cell density and central corneal thickness of cat eyes. Our finding indicates that sodium ferulate from 25 to 200 mg/L significantly reduced 2 g/L lidocaine-induced toxicity to human corneal endothelial cells, and 50 mg/L sodium ferulate recovered the damaged human corneal endothelial cells to normal growth status. Furthermore, 100 mg/L sodium ferulate significantly inhibited lidocaine-induced corneal endothelial cell loss and corneal thickening in cat eyes. In conclusion, sodium ferulate protects human corneal endothelial cells from lidocaine-induced cytotoxicity and attenuates corneal endothelial cell loss and central corneal thickening of cat eyes after intracameral injection with lidocaine. It is likely that the antioxidant effect of sodium ferulate reduces the cytotoxic and inflammatory corneal reaction during intracameral anaesthesia.

Lidocaine-Assisted Xylocaine Jelly Anesthesia versus one Quadrant Sub-Tenon Infiltration for Self-Sealing Sclerocorneal Incision Routine Phacoemulsification

Purpose

To compare the effect of Xylocaine jelly and intracameral lidocaine with one quadrant instant sub-Tenon infiltration for self-sealing sclerocorneal phacoemulsification.

METHODS

One hundred patients were enrolled into a prospective randomized study, receiving either a combination of topical 2% Xylocaine jelly and 0.5 ml of intracameral 1% lidocaine or sub-Tenon infiltration with 2 ml of 2% Xylocaine on the operating table. All patients underwent a standard divide and conquer phacoemulsification procedure through a superior sclerocorneal frown incision followed by implantation of a polymethylmethacrylate intraocular lens. Intraoperative pain was indicated by the patient by squeezing the bedside nurse's hand, who allocated it to particular stages of surgery on a chart. After surgery, patients assessed the pain experienced using a 10-unit visual analogue scale.

Results

Pain was indicated on 31 occasions during the operation in the sub-Tenon group (mainly the injection itself) and 67 times in the topical group. The median overall subjective pain score was 3 in the jelly group and 0 in the sub-Tenon. Five eyes (10%) had to be converted to sub-Tenon during the surgery because of intolerable pain.

CONCLUSIONS

Whereas lidocaine supported Xylocaine jelly anesthesia provided acceptable analgesia for 90% of patients operated, sub-Tenon anesthesia proved to deliver better intraoperative comfort in all patients receiving sclerocorneal incision cataract surgery.

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.

A single drop of 0.5% proparacaine hydrochloride for uncomplicated clear corneal phacoemulsification

Purpose:

The purpose of this study was to compare the efficacy of a single drop of 0.5% proparacaine hydrochloride in uncomplicated cataract surgery with phacoemulsification.

Materials and Methods:

Two hundred and ninety five patients scheduled for the phacoemulsification were divided into 2 groups based on the anesthetic agents they were to receive: 146 patients who received a single drop of 0.5% proparacaine 2 min before the start of the surgery (proparacaine group) and; 149 patients who received supplementation of 0.5% intracameral preservative free xylocaine (xylocaine group). A single surgeon performed all surgeries. Intraoperative and post-operative pain scores were evaluated on a visual analog scale. The surgeon noted his subjective impression of corneal clarity, discomfort while performing the surgery any supplemental anesthesia required and intraoperative complications. An anesthetist noted vital parameters and the need for intravenous sedation. Total surgical time was noted. Comparison of parameters was performed with the Chi-square test, and A P value less than 0.05 was considered as statistically significant.

Results:

No statistically significant difference was seen in the intraoperative (P = 0.24) and post-operative (P = 0.164) pain scores between groups. There was no pain (0 score) in 41.8% of patients in the proparacaine group and 46.3% of patients in the xylocaine group. The average surgical time (P = 0.279) and surgeon discomfort (P = 0.07) were not statistically significantly different between groups. No patients required supplemental anesthesia. There were no surgical complications that could compromise the visual outcome. An equal number of patients in both groups preferred same type of anesthetic technique for the fellow eye cataract surgery (89.11% for the proparacaine group and 90.18% for the xylocaine group). No patients in either group had changes in vital parameters or required intravenous sedation.

Conclusion:

A single drop pre-operatively, of proparacaine hydrochloride was comparable to the intracameral supplementation of preservative free xylocaine for phacoemulsification in uncomplicated cataract surgery without compromising the visual outcome. However, we recommend individualizing the anesthetic technique according to the requirements of the surgeon.

The effect of combined topical-intracameral anaesthesia on neuroleptic requirements during cataract surgery

OBJECTIVE

To evaluate whether the addition of intracameral lidocaine to topical anaesthesia during cataract surgery leads to a decrease in the administration of intraoperative midazolam and fentanyl.

DESIGN

Retrospective case-control study.

PARTICIPANTS

The eyes of 124 patients undergoing phacoemulsification were included in the study, with 62 in the intracameral group and 62 in the control group.

METHODS

A single-centre, retrospective chart review of cases between April and October 2007 in which patients had undergone small-incision phacoemulsification with foldable intraocular lens insertion and received preoperatively either topical tetracaine 0.5% with unpreserved intracameral lidocaine 1% (intracameral group) or topical tetracaine 0.5% alone (control group). Intraoperatively, midazolam and fentanyl were administered as needed based on pain and anxiety.

RESULTS

A total of 124 eyes (124 patients) were included. There was no statistically significant difference between the mean intraoperative midazolam doses given for the 2 groups (p = 0.08). The mean intraoperative dose of fentanyl was lower in the intracameral than in the control group (p < 0.0001). A comparison of intraoperative fentanyl requirements between groups using a multivariate regression analysis for age, gender, surgical time, and preoperative fentanyl levels confirmed the lower need for intraoperative fentanyl in the intracameral compared with the control group (p = 0.0037). There were no anaesthetic complications among any of the study patients.

CONCLUSIONS

Patients receiving topical tetracaine 0.5% with unpreserved intracameral lidocaine 1% during cataract surgery demonstrated a reduction in intraoperative fentanyl requirements. Surgeons performing cataract surgery under topical anaesthesia should consider the addition of intracameral lidocaine 1% to decrease fentanyl requirements and improve patient safety and comfort.

Manual small incision cataract surgery under topical anesthesia with intracameral lignocaine: study on pain evaluation and surgical outcome

The authors here describe manual small incision cataract surgery (MSICS) by using topical anesthesia with intracameral 0.5% lignocaine, which eliminates the hazards of local anesthesia, cuts down cost and time taken for the administration of local anesthesia.

Sub-Tenon's anaesthesia versus topical anaesthesia for cataract surgery

BACKGROUND

Local anaesthesia for cataract surgery can be provided by either sub-Tenon or topical anaesthesia. Although there is some work suggesting advantages to both techniques, there has been no recent systematic attempt to compare both techniques for all relevant outcomes.

OBJECTIVES

To compare the effectiveness of topical anaesthesia (with or without the addition of intracameral local anaesthetic) and sub-Tenon's anaesthesia in providing pain relief during cataract surgery.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (The Cochrane Library, 2006, Issue 2); MEDLINE (1990 to July 2006); EMBASE (1990 to July 2006) and reference lists of articles. There were no constraints based on language or publication status.

SELECTION CRITERIA

We included all randomized or quasi-randomized studies comparing sub-Tenon anaesthesia with topical anaesthesia for cataract surgery.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information. We also collected adverse effects information from the trials.

MAIN RESULTS

Seven studies involving 617 patients with 742 eyes operated on were examined. Five studies used unpaired data, with a single eye operated on; two studies used paired data with both eyes operated on. The surgical technique was clear corneal incision in five studies and scleral tunnel in two. The overall quality of the studies was not high, with one study triple blind (patient, surgeon and assessor blinded to treatment group) and three others single blind. The allocation of concealment and methods of randomization were only described in two studies. Three unpaired studies showed that sub-Tenon anaesthesia provided better intra-operative pain relief than topical anaesthesia (pooled weighted mean difference (fixed) 1.28, 95% CI 0.83to 1.72). The differences in the pain scores are not necessarily clinically significant although statistically significant. The differences are not large in magnitude and are skewed to the low end of the visual analogue scale but the studies are consistent throughout in reporting more pain in the topical anaesthesia group. This was also supported by the one paired study which showed that the mean pain score in the topical group was 1.13 (SD 1.57) compared with 0.57 (SD 1.28) in the sub-Tenon group (P < 0.001). Three of the studies used a 10-point visual analogue scale, while one used a novel 5-point scale. Further support was provided by other outcome measures. Sub-Tenon anaesthesia caused more chemosis and sub-conjunctival haemorrhage although this was purely aesthetic. The more serious complication of posterior capsule tear and vitreous loss occurred twice as much in the topical group than with sub-Tenon anaesthesia (4.3% versus 2.1%).

AUTHORS' CONCLUSIONS

Sub-Tenon anaesthesia provides better pain relief than topical anaesthesia for cataract surgery.

Topical anaesthesia alone versus topical anaesthesia with intracameral lidocaine for phacoemulsification

BACKGROUND

Cataract is defined as loss of transparency of the natural lens and is usually an age-related phenomenon. The only recognized treatment available for cataract involves surgery. An ideal anaesthetic should allow for pain-free surgery with no systemic or local complications. It should be cost effective and should facilitate a stress-free procedure for surgeon and patient alike. Topical anaesthesia involves applying anaesthetic eye drops to the surface of the eye prior to and during surgery. This has found large acceptance especially in the USA where it is used by 61% of cataract surgeons. Many surgeons who perform cataract surgery under topical anaesthesia also use intraoperative supplementary intracameral lidocaine (injected directly into the anterior chamber of the eye). The benefits and possible risks of intracameral lidocaine have been assessed by a number of randomized controlled trials, but the results have been conflicting and many of the endpoints have been heterogeneous.

OBJECTIVES

The primary objective of this systematic review was to assess pain during surgery and patient satisfaction with topical anaesthesia alone compared to topical anaesthesia with intracameral anaesthesia for phacoemulsification. The secondary objectives were to assess adverse effects and complications attributable to choice of anaesthesia and the need for additional anaesthesia during surgery.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2006, Issue 2), MEDLINE (1966 to May 2006), EMBASE (1980 to May 2006) and LILACs (1982 to 3 May 2006). We also searched the reference lists of the identified studies and the Science Citation Index. We did not have any language restriction.

SELECTION CRITERIA

We included only randomized controlled trials (RCTs) comparing topical anaesthesia alone to topical anaesthesia with intracameral lidocaine.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial quality and extracted data. For dichotomous outcomes data were presented as odds ratios. For continuous outcomes the weighted mean difference was employed. A random-effects model was used unless there were fewer than three trials in a comparison, where a fixed-effect model was used. We explored heterogeneity between trial results using a chi-squared test.

MAIN RESULTS

A total of eight trials comprising of 1281 patients were identified for analysis. Our data comparison showed a significantly lower intraoperative pain perception in patient groups using supplementary intracameral lidocaine, although the difference was small. No significant difference was demonstrated between the groups receiving topical anaesthesia alone and topical combined with intracameral anaesthesia in terms of the need for supplemental anaesthesia, intraoperative adverse events or corneal toxicity.

AUTHORS' CONCLUSIONS

The use of intracameral unpreserved 1% lidocaine is an effective and safe adjunct to topical anaesthesia for phacoemulsification cataract surgery.

Randomized comparative clinical study of cryoanalgesia versus topical anesthesia in clear corneal phacoemulsification

PURPOSE

To compare intraoperative pain scores and objective stress signs during clear corneal phacoemulsification under cryoanalgesia and topical anesthesia.

SETTING

Hospital Ramón y Cajal, Madrid, and Hospital Universitario Nuestra Sra. de la Candelaria, Tenerife, Canary Islands, Spain.

METHODS

Eighty-two patients were randomized to have phacoemulsification under cryoanalgesia or topical anesthesia. Uncooperative patients and those with shallow anterior chamber and small pupils were excluded. In case of breakthrough pain during the surgery, a supplemental anesthesia protocol was established. Each patient was asked to grade the severity of pain on a 4-point scale (verbal description score; 0=none, 1=little, 2=some, or 3=much). Immediately after surgery, the general discomfort and pain were evaluated. Surgeon stress was evaluated during surgery. A comparison of the 2 groups was performed using a statistical analysis of variance.

RESULTS

Supplemental anesthesia was required in 1 patient in each group. A total of 95.23% of patients would repeat the same technique under cryoanalgesia versus 97.5% under topical anesthesia. Similar pain levels and surgical stress scores were noted in both groups.

CONCLUSIONS

Cryoanalgesia clear corneal phacoemulsification was safe with an acceptable level of pain. It induced a physiological stress response to that of topical anesthesia (blood pressure and heart rate). Cryoanalgesia was preferred over topical anesthesia by some patients. It is a suitable technique for anesthetic allergy cases.

Advances in ophthalmic regional anaesthesia

Although retrobulbar and peribulbar regional anaesthetic techniques are used (by both anaesthesiologists and ophthalmologists) in various types of eye surgery, topical anaesthesia of the conjunctiva and cornea, followed--as needed--by sub-Tenon's block, is now common in routine cataract surgery. Intracameral administration of local anaesthetic by the ophthalmologist is also performed. Sedation during ophthalmic surgery is distinctly lighter than for other surgery because it is essential that the patient remains alert and can cooperate with the surgeon. Continuous insufflation of oxygen-enriched air is needed to ascertain that CO2 has been flushed away. With a catheter placed into the nostril, the patient (whose head is draped and 'hidden') can have the end-tidal CO2 monitored. Finger index (FI), a palpation method that assesses the ease of performing retrobulbar block, is introduced. Because of the risk of life-threatening complications in ophthalmic regional anaesthesia, the services of an anaesthesiologist must be available and training of anaesthesia residents in ophthalmic regional anaesthesia is highly recommended.

Viscoanesthesia. Part I: toxicity to corneal endothelial cells in a rabbit model

PURPOSE

To evaluate the toxicity of a solution combining sodium hyaluronate 1.5% with lidocaine (0.5%, 1.0%, or 1.65%) to the rabbit corneal endothelium.

SETTING

Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA.

METHODS

Each rabbit cornea was excised, and the endothelium was exposed to 1 of the following solutions for 20 minutes: viscoanesthetic solution (0.5%, 1.0%, or 1.65% lidocaine in sodium hyaluronate 1.5%; 5 corneas each), sodium hyaluronate 1.5% (n = 5), balanced salt solution (BSS(R)) (n = 5), mitomycin-C 0.02% (n = 2), dextran 15% (n = 2), or distilled water (n = 2). The endothelium was then stained with trypan blue and alizarin red. Two corneas were stained immediately after excision. Cell morphology and damage to the corneal endothelium were analyzed by microscopic examination.

RESULTS

The endothelium in the corneas of the viscoanesthetic groups was comparable to that in the sodium hyaluronate 1.5% and the BSS groups and to the corneas not exposed to any solution. In some areas of the 1.0% and the 1.65% viscoanesthesia groups, the corneal endothelial cells presented irregular intercellular borders. Staining with trypan blue, which indicates cellular damage, was observed in some linear areas corresponding to corneal folds in all groups. The folds were probably caused during manipulation for corneal excision and staining. The corneal endothelium was destroyed in the mitomycin group. In the dextran and distilled-water groups, morphological alterations probably resulting from osmotic changes were observed.

CONCLUSIONS

The 3 concentrations of viscoanesthetic solutions appeared to be safe to rabbit corneal endothelium.

Viscoanesthesia. Part II: toxicity to intraocular structures after phacoemulsification in a rabbit model

PURPOSE

To investigate the toxicity of a solution that combines sodium hyaluronate 1.5% with lidocaine (0.5%, 1.0%, or 1.65%) to intraocular structures.

SETTING

Center for Research on Ocular Therapeutics and Biodevices, Storm Eye Institute, Medical University of South Carolina, Charleston, South Carolina, USA.

METHODS

Phacoemulsification was performed in both eyes of 29 rabbits. They were divided into 3 groups; in each group (n = 7), 1 viscoanesthetic solution was used before capsulorhexis. After irrigation/aspiration, 0.2 mL of the solution was purposely left in the capsular bag. In 1 rabbit in each group, the solution was injected into the vitreous cavity through a posterior capsulorhexis. In 8 rabbits used as controls, balanced salt solution (BSS(R)) (n = 4) or sodium hyaluronate 1.5% (n = 4) was injected into the vitreous cavity. Enucleations were performed 15, 30, and 60 days postoperatively. Histological sections were cut and stained with hematoxylin-eosin, periodic acid-Schiff, and Masson trichrome stains.

RESULTS

Light microscopic evaluation of the eyes enucleated after 15, 30, and 60 days in the study and control groups showed similar findings in intraocular structures such as the ciliary body and retina. No evidence of an inflammatory reaction, cell necrosis, or cell degeneration was observed in the histological sections.

CONCLUSIONS

The use of viscoanesthesia during phacoemulsification appeared to be safe, with no histologic abnormalities observed with the 3 lidocaine concentrations. The efficacy of the anesthetic effects of these solutions will be addressed in clinical trials.

Ophthalmic regional anaesthesia

PURPOSE OF REVIEW

To summarize recent knowledge concerning ophthalmic regional anaesthesia.

RECENT FINDINGS

Ophthalmic regional anaesthesia has changed considerably over the past few years. Alternatives to retrobulbar anaesthesia have been proposed to reduce the number of complications without detriment to efficiency. Finally new local anaesthetics have been adopted and the indications have broadened, especially in vitroretineal surgery.

SUMMARY

New developments in ophthalmic regional anaesthesia are presented in this review. Different methods, indications and side effects are described in order to facilitate the clinician's choice, without any claim to single out an ideal technique.