Peribulbar versus retrobulbar anaesthesia for cataract surgery

Regional Anaesthesia, Contemporary Techniques, and Associated Advancements: A Narrative Review

In particular, the application of regional anaesthesia techniques in existing medicine can be characterized as experiencing regular changes in recent decades. It is useful for obtaining accurate and efficient pain management solutions, from the basic spinal and epidural blocks to the novel ultrasound nerve blocks and constant catheter procedures. These advancements do enhance not only the value of the perioperative period but also the patient's rated optimization as enhancing satisfaction, better precision, and the safety of nerve block placement. The use of ultrasound technology makes it even easier to determine the proper positioning of the needle and to monitor nerve block placement. Moreover, the duration and efficiency of regional anaesthesia are being enhanced by state-of-the-art approaches, which come in the form of liposomal bupivacaine, and better recovery plans and protocols, which shorten recovery time and decrease the number of hospital days. As these methods develop further, more improvements in the safety, efficacy, and applicability of regional anaesthesia in contemporary medicine are anticipated through continued research and innovation.

Levobupivacaine Combined with Cisatracurium in Peribulbar Anaesthesia in Cats Undergoing Corneal and Lens Surgery

The aims of the study included evaluating the effects of levobupivacaine combined with cisatracurium on akinesia and mydriasis when administered by peribulbar injection, and evaluating if the chosen dose of cisatracurium is enough to avoid the use of systemic neuromuscular blockade in cats. The animals were divided into four groups as follows: group L received 1.25 mg kg^-1 levobupivacaine administered by peribulbar injection; group LC received the same dose of levobupivacaine combined with 0.01 mg kg^-1 of cisatracurium administered by peribulbar injection; group C received 0.01 mg kg^-1 of cisatracurium administered by peribulbar injection; group GC received 0.01 mg kg^-1 of cisatracurium intravenously. Physiological variables, intraocular pressure, akinesia, and mydriasis were measured before and up to 30 min after peribulbar injection. The onset of akinesia, duration of akinesia, and train of four (TOF) were evaluated. Physiological variables remained in the physiological range in all groups. Effective akinesia and mydriasis were observed in all groups. The (TOF) was 0.9 in all groups. Throughout the study was observed in group LC a shortened onset of akinesia and a prolonging its duration. The peribulbar injection of cisatracurium and levobupivacaine provided effective akinesia and mydriasis, and shortened the onset of akinesia while prolonging its duration.

Local anaesthesia as a standard of care for penetrating keratoplasty?

BACKGROUND/OBJECTIVES

To determine preferences in the use of local anaesthesia (LA) versus general anaesthesia (GA) for penetrating keratoplasty (PK), and to examine the safety of LA for PK.

SUBJECTS/METHODS

A retrospective analysis of PKs performed at an ophthalmology department in Canada from 01/01/2008 to 01/01/2020 was conducted to investigate rate of major complications. A questionnaire was also sent out to cornea specialists in the United Kingdom (UK) and Canada to determine trends in anaesthesia use for PK. Data on anaesthesia use in keratoplasty data was also obtained from the National Health Service Blood and Tissue (NHSBT) register.

RESULTS

The retrospective study found that 2143 PKs were performed under LA by 4 surgeons. The following complications were revealed: 1 acute anxiety attack with tachycardia, 3 extraocular myotoxicity cases requiring squint surgery, 1 expulsive suprachoroidal haemorrhage and 1 retrobulbar haemorrhage. The survey revealed 92% of cornea specialists in Canada preferred LA to GA. In the UK, 4.5% of specialists preferred LA, with most preferring GA due to suprachoroidal haemorrhage risk. NHSBT data revealed that 86.6% of 6181 PKs performed in UK between 01/04/2015 and 31/03/2020 were done under GA.

CONCLUSIONS

LA is preferred for PK in Canada, in contrast to the UK where GA is preferred. Our retrospective study suggests a low incidence of LA-related complications. We suggest that LA should be considered for most cornea transplant techniques, including optical penetrating keratoplasty. Rising worldwide keratoplasty numbers, ageing populations and risks of pandemics (e.g. COVID-19) give more reason for reduced reliance on GA.

Comparing Blind and Ultrasound-Guided Retrobulbar Nerve Blocks in Equine Cadavers: The Training Effect

Simple Summary

Standing ophthalmic surgeries have become more and more common in horses. For these standing surgeries, the blind retrobulbar block is often used for anesthesia and akinesia of the eye. However, placing a retrobulbar block using this blind technique can lead to complications, for example, penetration of the globe, nerve injury or chemosis due to spreading of the local anesthetic in the region of the globe. For this reason, it might be better to perform the retrobulbar block using guidance by ultrasound. Ultrasound-guided retrobulbar block has only been described twice in the literature using equine cadavers. Comparison of the ultrasound-guided peribulbar technique to the blind technique has only been carried out once. Furthermore, the learning curve of ultrasound-guided retrobulbar nerve block placement has not been evaluated. Our study aimed to compare the blind and ultrasound-guided approaches to retrobulbar block placement in horses and to evaluate the success and complication rates, analyzing the effect of training on ultrasound guidance. A trend towards a significant improvement in accuracy was seen for ultrasound guidance, and larger scale follow-up studies might show a significant training effect on the use of ultrasound in retrobulbar nerve block placement and that the use of ultrasound guidance could be promising.

Abstract

In standing ophthalmic surgery in horses, a retrobulbar nerve block (RNB) is often placed blindly for anesthesia and akinesia. The ultrasound (US)-guided RNB may have fewer complications, but the two techniques have only been compared once in equine cadavers. This study compares the techniques for success and complication rates and analyzes the effect of training on US guidance. Twenty-two equine cadavers were divided into three groups: blind RNBs were performed bilaterally in eight cadavers, US-guided RNBs were performed bilaterally in seven cadavers, and after US-guided training, blind RNBs were performed bilaterally in seven cadavers. All RNBs were performed by the same two inexperienced operators, and a combination of contrast medium (CM; 1.25 mL) and methylene blue dye (1.25 mL) were injected (2.5 mL total volume). Needle positioning in the periorbita and the distance of the CM to the optic foramen were assessed using computerized tomography (CT). Dye spreading was evaluated by dissection. In group 1, 37.5% of the injections were in the optimal central position in the periorbita; in group 2, 75% and in group 3, 71.4%. There was no significant difference between the groups regarding needle position (groups 1 and 2 p = 0.056; groups 1 and 3 p = 0.069, groups 2 and 3 p = 0.8). The mean CM distribution distance was not significantly different between all groups. Group 1 had 18.75% intraocular injections versus 0% in group 2 and 7.1% in group 3 (not significant). US guidance showed no significant increases in accuracy nor decreases in complications. However, the effects on accuracy showed a trend towards significant improvement, and larger scale follow-up studies might show significant training effects on US guidance.

Peribulbar anesthesia for strabismus surgery in adult patients

PURPOSE

To evaluate the efficacy and safety of peribulbar anesthesia during strabismus surgery.

METHODS

Medical records of patients undergoing strabismus surgery and peribulbar anesthesia were reviewed. The overall efficacy of peribulbar anesthesia was evaluated as requirement of supplemental peribulbar anesthesia, impossibility to perform eye muscles surgery due to inadequate efficacy of the block and peribulbar block complications that occurred up to 6 weeks postoperatively. Presence of oculocardiac reflex (OCR) and presence of decreased visual acuity and afferent pupillary defect postoperatively were reported.

RESULTS

A total of 510 patients comprised our study group. The total amount of peribulbar injections was 717. Four patients (0.7%) required supplemental injection in the superonasal quadrant. Five of 510 (0.9%) required an anesthesiologic intervention with intravenous atropine. Eighty patients of 510 (15.6%) complained about transitory complete ptosis and/or amaurosis postoperatively. No complications were observed up to 6 weeks postoperatively.

CONCLUSION

Peribulbar anesthesia was an effective and safe option during strabismus surgery in adult patients.

Assessment of Visual and Retinal Function Following In Vivo Genipin-Induced Scleral Crosslinking

Purpose

Genipin has been proposed as a possible neuroprotective therapy in myopia and glaucoma. Here, we aim to determine the effects of prolonged genipin-induced scleral stiffening on visual function.

Methods

Eyes from Brown Norway rats were treated in vivo with either a single 15 mM genipin retrobulbar injection or sham retrobulbar injection and were compared to naïve eyes. Intraocular pressure, optomotor response, and electroretinograms were repeatedly measured over 4 weeks following retrobulbar injections to determine visual and retinal function. At 4 weeks, we quantified retinal ganglion cell axon counts. Finally, molecular changes in gene and protein expression were analyzed via real-time polymerase chain reaction (RT-PCR) and proteomics.

Results

Retrobulbar injection of genipin did not affect intraocular pressure (IOP) or retinal function, nor have a sustained impact on visual function. Although genipin-treated eyes had a small decrease in retinal ganglion cell axon counts compared to contralateral sham-treated eyes (−8,558 ± 18,646; mean ± SD), this was not statistically significant (P = 0.206, n = 9). Last, we did not observe any changes in gene or protein expression due to genipin treatment.

Conclusions

Posterior scleral stiffening with a single retrobulbar injection of 15 mM genipin causes no sustained deficits in visual or retinal function or at the molecular level in the retina and sclera. Retinal ganglion cell axon morphology appeared normal.

Translational Significance

These results support future in vivo studies to determine the efficacy of genipin-induced posterior scleral stiffening to help treat ocular diseases, like myopia and glaucoma.

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.

Ultrasound detection of iatrogenic injury during peribulbar eye block: a cadaveric study

Background

Ophthalmic eye blocks, such as retrobulbar, peribulbar and sub-Tenon’s, are traditionally conducted “blind”. Complications are rare but potentially devastating. Life-threatening complications include brain stem anesthesia and local anesthetic toxicity, whereas sight-threatening complications include globe perforation, optic nerve damage and ocular muscle damage. Ultrasound permits a view of orbital structures and can be used to guide needle placement. The ultrasound appearances of unintended local anesthetic injection into vital orbital structures have not been documented. This study aimed to record the ultrasound appearances of unintended injection locations.

Methods

The spherical shape of the eyeballs of three soft-fix Thiel embalmed human cadavers were restored using glycerol. Iatrogenic injury in peribulbar block was then simulated through injection of printers’ ink mixed with Thiel embalming fluid. Ultrasound was used to guide the needles and the tips were redirected to lie within the globe, lateral rectus and optic nerve. Ultrasound images were recorded during injection. The orbital cavities were then dissected via a superior approach to record the location and extent of injectate spread.

Results

Real-time globe rupture, ocular muscle injection and optic nerve injection were visible using ultrasound. Characteristic appearances were identified in each case. Dissection confirmed needle and injection placement.

Conclusions

The ultrasound appearance of block complications is important to document and should be an integral part of regional anesthesia training. This study is the first to provide such images for ophthalmic nerve blocks. It offers ophthalmic anesthetists and ophthalmologists the potential to diagnose severe complications rapidly and accurately with a potential impact on patient safety.

Prolonged Duration Topical Corneal Anesthesia With the Cationic Lidocaine Derivative QX-314

Purpose

Topical corneal local anesthetics are short acting and may impair corneal healing. In this study we compared corneal anesthesia and toxicity of topically applied N-ethyl lidocaine (QX-314) versus the conventional local anesthetic, proparacaine (PPC).

Methods

Various concentrations of QX-314 and 15 mM (0.5%) PPC were topically applied to rat corneas. Corneal anesthesia was assessed with a Cochet-Bonnet esthesiometer at predetermined time points. PC12 cells were exposed to the same solutions to assess cytotoxicity. Repeated topical corneal administration in rats was then used to assess for histologic evidence of toxicity. Finally, we created uniform corneal epithelial defects in rats and assessed the effect of repeated administration of these compounds on the defect healing rate.

Results

QX-314 (15 mM) and PPC (15 mM) caused similar total duration (114 ± 17 and 87 ± 16 minutes, respectively; P = 0.06) of anesthesia. The depth of anesthesia was similar between these low-dose groups at 15 minutes after application (1.8 ± 0.3- and 2.0 ± 0.8-cm filament lengths). QX-314 (100 mM) provided more prolonged corneal anesthesia (174 ± 13 minutes; P < 0.0001), with improved depth at 15 minutes (0.7 ± 0.3-cm filament length; P = 0.007). All tested concentrations of QX-314 demonstrated similar or less toxicity than 0.5% PPC.

Conclusions

Topical administration of QX-314 is effective for corneal anesthesia and demonstrates no histologic signs of local toxicity in a rodent model. In higher concentrations, QX-314 provides more than twofold the duration of anesthetic effect than does 0.5% PPC.

Translational Relevance

Our study reveals a clinically relevant compound providing prolonged duration topical corneal anesthesia.

Identification and Description of Reliable Evidence for 2016 American Academy of Ophthalmology Preferred Practice Pattern Guidelines for Cataract in the Adult Eye

Importance

Trustworthy clinical practice guidelines require reliable systematic reviews of the evidence to support recommendations. Since 2016, the American Academy of Ophthalmology (AAO) has partnered with Cochrane Eyes and Vision US Satellite to update their guidelines, the Preferred Practice Patterns (PPP).

Objective

To describe experiences and findings related to identifying reliable systematic reviews that support topics likely to be addressed in the 2016 update of the 2011 AAO PPP guidelines on cataract in the adult eye.

Design, Setting, and Participants

Cross-sectional study. Systematic reviews on the management of cataract were searched for in an established database. Each relevant systematic review was mapped to 1 or more of the 24 management categories listed under the Management section of the table of contents of the 2011 AAO PPP guidelines. Data were extracted to determine the reliability of each systematic review using prespecified criteria, and the reliable systematic reviews were examined to find whether they were referenced in the 2016 AAO PPP guidelines. For comparison, we assessed whether the reliable systematic reviews published before February 2010 the last search date of the 2011 AAO PPP guidelines were referenced in the 2011 AAO PPP guidelines. Cochrane Eyes and Vision US Satellite did not provide systematic reviews to the AAO during the development of the 2011 AAO PPP guidelines.

Main Outcomes and Measures

Systematic review reliability was defined by reporting eligibility criteria, performing a comprehensive literature search, assessing methodologic quality of included studies, using appropriate methods for meta-analysis, and basing conclusions on review findings.

Results

From 99 systematic reviews on management of cataract, 46 (46%) were classified as reliable. No evidence that a comprehensive search had been conducted was the most common reason a review was classified as unreliable. All 46 reliable systematic reviews were cited in the 2016 AAO PPP guidelines, and 8 of 15 available reliable reviews (53%) were cited in the 2011 PPP guidelines.

Conclusions and Relevance

The partnership between Cochrane Eyes and Vision US Satellite and the AAO provides the AAO access to an evidence base of relevant and reliable systematic reviews, thereby supporting robust and efficient clinical practice guidelines development to improve the quality of eye care.

Combined retro-peribulbar and subconjunctival anesthesia for evisceration surgery

PURPOSE

To evaluate the efficacy of retro-peribulbar and subconjunctival anesthesia associated with intravenous sedation in patients undergoing evisceration and orbital implant placement.

METHODS

The charts of 217 patients who underwent evisceration with trans-scleral implant placement were reviewed. Midazolam and fentanyl were used for intravenous sedation. For local anesthesia, a combination of lidocaine with epinephrine and bupivacaine was injected into the retrobulbar, upper peribulbar, and subconjunctival areas. The intraoperative pain and need for supplemental anesthetic injection were recorded prospectively.

RESULTS

The surgery was performed with local anesthesia in 116 patients (53%) and with general anesthesia in 101 patients (47%). Patients were significantly older in the local anesthesia group than in the general anesthesia group (mean age, 59.9 years vs 45.2 years; P < .05). Supplemental retrobulbar anesthesia was required in 5 patients (4.3%). Transition to general anesthesia was required in 1 patient (0.9%) due to severe anxiety. Orbital hemorrhage developed after retrobulbar injection in 1 patient (0.9%), but did not preclude performing evisceration.

CONCLUSIONS

Combined retro-peribulbar and subconjunctival anesthesia with intravenous sedation can provide safe and effective intraoperative analgesia for evisceration surgery with trans-scleral implant placement.

Retrobulbar anaesthesia for adjustable strabismus surgery in adults: a prospective observational study

OBJECTIVE

To characterize the ocular response to retrobulbar anaesthesia and to evaluate the efficacy of retrobulbar anaesthesia for adjustable strabismus surgery in adults.

DESIGN

Prospective observational study.

PARTICIPANTS

Adult patients undergoing adjustable strabismus surgery under retrobulbar anaesthesia.

METHODS

Surgical success was defined by ocular alignment within 10 prism diopters (PD) of orthotropia for horizontal rectus surgery and within 5 PD for vertical rectus surgery. After retrobulbar injection of Xylocaine with epinephrine, the onset time and the degree of visual impairment, ocular akinesia, and analgesia were evaluated. Postoperative parameters included the restoration of vision, onset of pain, resolution of ptosis, normalization of pupil, resolution of extraocular motility deficits, and the timing of postoperative adjustment. Perioperative complications were also documented.

RESULTS

A total of 33 patients were initially included in this study. Two patients experienced complications (perioperative retrobulbar hemorrhage, postoperative suprachoroidal hemorrhage) and were excluded from data analysis. Of the remaining 31 patients (mean age, 50.2 ± 14.8 years), surgical outcome was satisfactory in 30/31 (96.8%) patients at the first postoperative visit and in 15/19 (78.9%) cases at last follow-up (mean, 6.1 ± 1.6 months). Excellent intraoperative ocular akinesia and analgesia was achieved with retrobulbar anaesthesia. After retrobulbar injection, visual impairment was the first to resolve to preoperative levels within (mean ± SD) 3.7 ± 1.9 hours postinjection, followed by onset of pain at 4.1 ± 1.0 hours, resolution of ptosis at 4.3 ± 1.9 hours, and normalization of pupil reactivity at 6.1 ± 1.0 hours. The resolution of anaesthesia upon extraocular motility occurred within 5.7 ± 1.0 hours postinjection (range, 4.5-8.0 hours), allowing for subsequent same-day postoperative adjustment.

CONCLUSIONS

Retrobulbar anaesthesia in the context of adult, adjustable strabismus surgery is a relatively safe and effective technique. It provides excellent intraoperative analgesia and akinesia. Retrobulbar anaesthesia enables for same-day suture adjustments to be reliably performed.

Real-time ultrasound-guided retrobulbar block vs blind technique for cataract surgery (pilot study)

Background

Retrobulbar regional eye block aims to ensure eye globe akinesia and anesthesia during ophthalmic surgery, and despite the rarity of occurrence of complications due to the blind needle passage while performing either peribulbar or retrobulbar block, some of them are serious and may be life threatening.

Aim

The aim of this study was to estimate the accuracy and safety of real-time ultrasound-guided retrobulbar regional anesthesia in comparison with the blind technique for cataract surgery.

Design

This was a prospective randomized controlled trial.

Methodology

A total of 30 patients who met the inclusion criteria were registered in our research and were divided into two groups: 15 patients received real-time ultrasound-guided retrobulbar block compared to 15 patients who received the block using the blind technique.

Results

One patient out of the 30 was excluded from the analysis, and no statistically significant differences were observed between the two groups regarding the onset of akinesia, numeric pain rating scores, rate of complications, and degree of patient and physician satisfaction.

Conclusion

There were no statistically significant difference between real-time ultrasound-guided and blind retrobulbar regional eye blocks concerning the onset of action, total volume of injected local anesthetic solution, supplemental injection required, pain scores, and degree of patient satisfaction.

[Oral anticoagulation : Current overview and perioperative management in ophthalmic surgery]

Antithrombotic treatment with oral anticoagulants and antiplatelet agents can increase the risk for perioperative bleeding. In contrast to other surgical fields, the optimal perioperative management in ophthalmic surgery has not yet been exactly defined and, thus, is not standardized. In this contribution, we provide an overview of currently available oral anticoagulants and discuss potential strategies for the management of these agents in different ophthalmic surgical procedures.

Use of hyaluronidase as an adjunct to local anaesthetic eye blocks to reduce intraoperative pain in adults

BACKGROUND

Hyaluronidase has been used over many decades as an adjunct to local anaesthetic solution to improve the speed of onset of eye blocks and to provide better akinesia and analgesia. With the evolution of modern eye surgery techniques, fast onset and akinesia are not essential requirements anymore. The assumption that the addition of hyaluronidase to local anaesthetic injections confers better analgesia for the patient needs to be examined. There has been no recent systematic review to provide evidence that hyaluronidase actually improves analgesia.

OBJECTIVES

To ascertain if adding hyaluronidase to local anaesthetic solutions for use in ophthalmic anaesthesia in adults results in a reduction of perceived pain during the operation and to assess harms, participant and surgical satisfaction, and economic impact.

SEARCH METHODS

We carried out systematic searches in Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and four other databases in June 2017. We searched the trial registers at www.ISRCTN.com, ClinicalTrials.gov and www.clinicaltrialsregister.eu for relevant trials. We imposed no language restrictions.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) that evaluated the effect of hyaluronidase on pain experienced by adults during intraocular surgery using a rating scale.

DATA COLLECTION AND ANALYSIS

Two review authors (HR and KA) independently extracted data and assessed methodological quality using standard procedures as expected by Cochrane.

MAIN RESULTS

We included seven trials involving 500 participants that studied the effect of hyaluronidase on intraoperative pain. Four of the seven trials with 289 participants reported the primary outcome in a dichotomous manner, and we proceeded to meta-analyse the findings which showed a moderate heterogeneity that could not be explained (I2 = 41% ). The pooled risk ratio (RR) for these four trials was 0.83 with the 95% confidence interval ranging from 0.48 to 1.42. The reduction in intraoperative pain scores in the hyaluronidase group were not statistically significant. Among the three trials that reported the primary outcome in a continuous manner, the presence of missing data made it difficult to conduct a meta-analysis. To further explore the data, we imputed standard deviations for the other studies from another included RCT (Sedghipour 2012). However, this resulted in substantial heterogeneity between study estimates (I² = 76% ). The lack of reported relevant data in two of the three remaining trials made it difficult to assess the direction of effect in a clinical setting.Overall, there was no statistical difference regarding the intraoperative reduction of pain scores between the hyaluronidase and control group. All seven included trials had a low risk of bias.According to GRADE, we found the quality of evidence was low and downgraded the trials for serious risk of inconsistency and imprecision. Therefore, the results should be analysed with caution.Participant satisfaction scores were significantly higher in the hyaluronidase group in two high quality trials with 122 participants. Surgical satisfaction was also superior in two of three high quality trials involving 141 participants. According to GRADE, the quality of evidence was moderate for participant and surgical satisfaction as the trials were downgraded for imprecision due to the small sample sizes. The risk of bias in these trials was low.There was no reported harm due to the addition of hyaluronidase in any of the studies. No study reported on the cost of hyaluronidase in the context of eye surgery.

AUTHORS' CONCLUSIONS

The effects of adding hyaluronidase to local anaesthetic fluid on pain outcomes in people undergoing eye surgery are uncertain due to the low quality of evidence available. A well designed RCT is required to address inconsistency and imprecision among the studies and to determine the benefit of hyaluronidase to improve analgesia during eye surgery. Participant and surgical satisfaction is higher with hyaluronidase compared to the control groups, as demonstrated in moderate quality studies. There was no harm attributed to the use of hyaluronidase in any of the studies. Considering that harm was only rarely defined as an outcome measure, and the overall small number of participants, conclusions cannot be drawn about the incidence of harmful effects of hyaluronidase. None of the studies undertook cost calculations with regards to use of hyaluronidase in local anaesthetic eye blocks.

Intraoperative head drift and eye movement: two under addressed challenges during cataract surgery

PURPOSE

To objectively measure head drift during cataract surgery, and subjectively simulate eye movements and assess impact on surgical technique.

MATERIALS AND METHODS

Twelve consecutively recorded routine cataract operations in the Tennent Institute of Ophthalmology, Gartnavel General Hospital, Glasgow, were reviewed. The speculum was used as a fixed point and correlated with a superimposed virtual ruler to measure maximum head drift in each direction throughout the operations. To simulate intraoperative eye movement, we attached string to the cataract surgical simulator (Eyesi) eye and manually induced abduction and adduction. A calibrated scale secured to the Eyesi head ensured 5 mm eye movements were consistently created. Ophthalmology trainees performed the continuous curvilinear capsulorhexis (CCC) exercise without and with sequential eye movements. Movements were induced every three seconds. Scores were compared using a paired Student's T-test.

RESULTS

Mean head drift in the surgical recordings was 3.1 mm medially (range 2-7 mm), 2.9 mm laterally (range 2-4 mm), 2.6 mm superiorly (range 1-5 mm), and 1.9 mm inferiorly (range 1-4 mm). In 11 of 12 cases, the operating microscope had to be adjusted for head drift. Six junior trainees completed the CCC module on the Eyesi without then with eye movements. After introducing eye movements the mean Eyesi score reduced from 92.7 to 76.9 (P = 0.014), 'roundness of rhexis' score reduced from 89.4 to 57.5 (P = 0.020), and trainees operated 17 s faster (P = 0.016).

CONCLUSION

This study objectively demonstrates the under-reported clinical scenario of head drift during cataract surgery. By manipulating the Eyesi we have shown that eye movements reduce the quality of cataract surgery.

Complication of Peribulbar Block: Brainstem Anaesthesia

Peribulbar block is used to obtain anaesthesia and akinesia of the eye by injecting a local anaesthetic around the musclecone. A patient scheduled for cataract surgery received peribulbar block with 6 mL of 2% lidocaine hydrochloride. Following the injection, confusion, hypotension and dilatation of the contralateral pupil rapidly progressed to loss of consciousness and respiratory arrest. The patient was intubated and mechanically ventilated for 30 min. The patient regained her consciousness, was extubated and transferred to the intensive care unit for further follow-up. Although brainstem anaesthesia because of peribulbar block is very rare, this procedure should be performed with complete monitorisation and resuscitation equipment.

The treatment methods for post-stroke visual impairment: A systematic review

AIM

To provide a systematic overview of interventions for stroke related visual impairments.

METHOD

A systematic review of the literature was conducted including randomized controlled trials, controlled trials, cohort studies, observational studies, systematic reviews, and retrospective medical note reviews. All languages were included and translation obtained. This review covers adult participants (aged 18 years or over) diagnosed with a visual impairment as a direct cause of a stroke. Studies which included mixed populations were included if over 50% of the participants had a diagnosis of stroke and were discussed separately. We searched scholarly online resources and hand searched articles and registers of published, unpublished, and ongoing trials. Search terms included a variety of MESH terms and alternatives in relation to stroke and visual conditions. Article selection was performed by two authors independently. Data were extracted by one author and verified by a second. The quality of the evidence and risk of bias was assessed using appropriate tools dependant on the type of article.

RESULTS

Forty-nine articles (4142 subjects) were included in the review, including an overview of four Cochrane systematic reviews. Interventions appraised included those for visual field loss, ocular motility deficits, reduced central vision, and visual perceptual deficits.

CONCLUSION

Further high quality randomized controlled trials are required to determine the effectiveness of interventions for treating post-stroke visual impairments. For interventions which are used in practice but do not yet have an evidence base in the literature, it is imperative that these treatments be addressed and evaluated in future studies.

Assessment of Optical Quality at Different Contrast Levels in Pseudophakic Eyes

Purpose. To assess visual function using Optical Quality Analysis System (OQAS) at varying levels of contrast in pseudophakic eyes. Methods. The study included patients admitted to Seoul St. Mary's Hospital between January and February 2012: 143 pseudophakic eyes with one of five intraocular lens types, examined 2–6 months after cataract surgery, and 93 normal eyes (enhanced visual acuity (VA) < 0.1 logMAR) in age-matched controls. Subjects were examined at three contrast levels using the OQAS. Results. At 100%, 20%, and 9% contrast, simulated mean VA was 0.16 ± 0.18 logMAR, 0.30 ± 0.18 logMAR, and 0.52 ± 0.17 logMAR, in normal eyes, and 0.16 ± 0.12 logMAR, 0.33 ± 0.20 logMAR, and 0.56 ± 0.21 logMAR, respectively, in pseudophakic eyes. Simulated VA decreased significantly when contrast was reduced, regardless of ocular status, age group, and lens type (p < 0.05). There were no significant differences between normal and pseudophakic eyes among subjects aged 50–69 (p > 0.05). Among subjects aged 70–79, pseudophakic eyes showed improved simulated VA (p = 0.000) and objective scattering index values (p = 0.008). Conclusions. Patients with intraocular lenses have similar or superior visual function when compared to those with normal eyes at 2–6 months after cataract surgery, even under low-contrast conditions.