Serious complications of local anaesthesia for cataract surgery: a 1 year national survey in the United Kingdom

BACKGROUND: The techniques of sub-Tenon's, topical and topical-intracameral local anaesthesia (LA) have become common in routine practice. AIMS: This study aimed (i) to estimate the frequency of various LA techniques used in cataract surgery, (ii) to estimate the incidence of severe adverse events associated with each LA technique, and (iii) to document these adverse events. METHODS: This was a prospective, 13 month observational study of routine practice in the UK in 2002-2003. The British Ophthalmological Surveillance Unit sent a monthly mailing to UK ophthalmologists, asking for reports of "potentially sight-threatening or life-threatening complications of LA for cataract surgery". Current LA practice was assessed by questionnaire. RESULTS: Cataract surgery comprised 4.1% general anaesthesia, 92.1% LA without sedation and 3.9% LA with sedation. Of the estimated 375 000 LAs 30.6% were peribulbar, 3.5% retrobulbar, 42.6% sub-Tenon's, 1.7% sub-conjunctival, 9.9% topical and 11.0% topical-intracameral LA. "Potentially sight-threatening complications" were mostly associated with retrobulbar and peribulbar techniques and "potentially life-threatening" complications with all techniques except topical/intracameral LA. Eight neurological complications consistent with brainstem anaesthesia were reported: 7 with peribulbar or retrobulbar LA. Poisson regression analysis strongly indicated that rates vary with technique (p<0.001 for "potentially sight-threatening" complications, p = 0.03 for "neurological" complications). Because of likely under-reporting, further complications probably occurred during the survey period. CONCLUSIONS: This large survey found a lower rate of reported serious complications with sub-Tenon's, topical and topical-intracameral LA compared with retrobulbar and peribulbar techniques. These "newer" methods may be preferable for routine cataract surgery.     

Combined propofol sedation with sub-Tenon's lidocaine/mercaine infusion for strabismus surgery in adults

AIMS: To evaluate the safety and efficacy of propofol sedation combined with sub-Tenon's anaesthesia for strabismus surgery in adults. METHODS: Thirty-two consecutive patients aged 31-85 years underwent strabismus surgery under general (n=16) or local (n=16) anaesthesia. In the local anaesthesia (study) group, sedation was induced with a loading dose of midazolam, fentanyl, and propofol, followed by continuous infusion of propofol, 3-6 mg/k/h to deep sedation. A nasal tube was inserted to prevent airway obstruction. Sub-Tenon's anaesthesia included infusion of a 3-4 ml mixture (50 : 50) of lidocaine 2%/mercaine 0.5%. General anaesthesia consisted of premedication with midazolam, followed by fentanyl, esmeron-bromate, propofol, and tracheal intubation. Duration of surgery and anaesthesia, intraoperative oculocardiac reflex and arrhythmias, time to discharge, postoperative pain, nausea and vomiting, and patient and surgeon satisfaction were evaluated. RESULTS: The local anaesthesia group had a significantly shorter operative and anaesthesia time, fewer episodes of oculocardiac reflex or arrythmia/bradycardia requiring treatment, fewer early or late episodes of nausea and vomiting, and less pain. The patients and surgeon in this group reported higher satisfaction. CONCLUSION: Propofol sedation with local sub-Tenon's injection of lidocaine/mercaine is recommended for the induction and maintenance of anaesthesia during unilateral or bilateral strabismus surgery in adults. The method is quick and effective, without systemic or ocular side effects.     

右美托咪定和咪达唑仑在老年人玻璃体手术中应用的对比研究

目的比较右美托咪定和咪达唑仑在老年人玻璃体手术中的不同作用。方法选择择期拟行玻璃体手术老年人患者40例,随机分为右美托咪定组(20例)和咪达唑仑组(20例)。两组患者球周阻滞麻醉后右美托咪定组给予右美托咪定,咪达唑仑组给予咪达唑仑。对比观察2组患者平均动脉压(mean arterial pressure,MAP)、心率(heart rate,HR)、Ramsay镇静评分、视觉模拟法(visual analogues cale,VAS)疼痛评分。结果两组患者术中不同时间MAP、HR与麻醉前比较,右美托咪定组各时间点均显著降低(均为P<0.05),咪达唑仑组各时间点均显著增高(均为P<0.05);右美托咪定组术中MAP、HR比咪达唑仑组显著降低,差异均有统计学意义(均为P<0.05)。两组患者术中不同时间的Ramsay镇静评分与麻醉前比较,均明显增高(均为P<0.05),两组之间差异无统计学意义(P>0.05)。两组不同时间的VAS疼痛评分与麻醉前比较,均有明显增高(均为P<0.05),两组之间差异无统计学意义(P>0.05)。右美托咪定组术中没有一例患者辅助使用芬太尼,无躁动、烦躁不安;咪达唑仑组有14例患者由于术中疼痛使用芬太尼,有3例出现呼吸抑制,需要暂时辅助人工通气可使脉搏氧饱和度维持在正常范围,有6例患者出现躁动。结论右美托咪定用于老年人玻璃体手术是安全、有效的,值得临床推广应用。     

Effect of sedation on visual sensations in patients undergoing cataract surgery under topical anaesthesia: a prospective randomized masked trial

Purpose: The main aim of the study was to determine whether intravenous sedation with midazolam reduces the ability of patients to see during cataract surgery performed under topical anaesthesia. We also sought to determine the effects of sedation on patient’s level of disturbance to the microscope light and visualization of surgical instruments and on the overall of experience of the patients during surgery. Methods: A total of 78 patients, aged 40–75 years, were randomly divided into two groups: Group S, (sedation) who received intravenous midazolam 0.015 mg/kg, and Group NS, (no sedation) who did not receive midazolam. Patients with history of anxiety, those with history of intraocular surgery and those with severe chronic obstructive pulmonary disease were excluded. Topical anaesthesia was achieved by the application of 2% xylocaine gel over the conjunctiva. A blinded observer interviewed all the patients 30 min after the surgery using a standard questionnaire. Results: Significant number of patients (25.6%) in Group NS was disturbed a lot because of the microscope light compared to Group S (5.1%), p = 0.021. Also, statistically significant number of patients in Group S (48.7%) compared to Group NS (20.5%) was not sure about the images perceived during surgery and were unable to recollect them after the surgery, p = 0.008, and 12.8% of the patients in Group NS reported the visual experience as frightening compared to 2.6% of patients in Group S, p = 0.239. Conclusion: Our study confirms that intravenous midazolam reduces both the ability to see and recall intraoperative visual images in patients undergoing cataract surgery under topical anaesthesia.     

Intravenous sedation for ocular surgery under local anaesthesia.

Anterior segment ophthalmic surgery is commonly performed under local anaesthesia. In order to improve patient comfort, a variety of sedation techniques has been employed in the past. The object of this study was, firstly, to determine whether continuous intravenous sedation during surgery offered any advantages in patients premedicated with temazepam and metoclopramide, and, secondly, to compare midazolam to propofol for this purpose. Forty nine patients were randomly allocated to receive no intravenous sedation (n = 15), continuous propofol infusion (n = 17), or continuous intravenous midazolam infusion (n = 17) after peribulbar anaesthesia. Each technique provided cardiovascular and respiratory stability and allowed early recovery with minimal postoperative sequelae. Unexpected ocular field movement occurred more commonly in the patients receiving intravenous sedation, although statistical significance was not shown (p = 0.06). Significantly more patients in the intravenous sedation groups reported amnesia (p = 0.03). Patient acceptability was good irrespective of the technique used. This study suggests that continuous sedation using propofol or midazolam is not beneficial and should be avoided in ophthalmic patients who have received a simple premedication.     

An evaluation of the administration of sub-Tenon local anaesthesia by a nurse practitioner

AIM: To evaluate the administration of sub-Tenon local anaesthesia (LA) by a nurse practitioner. METHODS: 106 consecutive patients listed for cataract surgery were given sub-Tenon's anaesthesia by a nurse practitioner. The surgical procedure was performed within 15 minutes of the administration of the LA. Pain, state and adequacy of anaesthesia, appearance of the eye, and patient anxiety were measured. Patients' experiences of this new nursing role were gained through interview. RESULTS: At the beginning of surgery, few patients showed eye movement in any of the four quadrants and the surgeons reported that akinesia was inadequate in only seven (7.1%) cases. Three patients (3.3%) gave a pain score of 3 out of 10 or above during surgery whereas the surgeons assessed the pain relief to be inadequate in eight (8.1%) cases. Five (5.3%) patients required a top up of anaesthesia and 51 (39.8%) patients developed conjunctival chemosis in two or more quadrants. Overall, patients' comments indicate that they were pleased with the new service. CONCLUSION: The results suggest that nurse practitioner delivered sub-Tenon LA is an effective and safe method of LA administration for cataract surgery.     

Effectiveness of oxygenation and suction in cataract surgery: is suction of CO2-enriched air under the drape during cataract surgery necessary?

PURPOSE: To investigate the effectiveness of aspiration of expired air by a suction system on peripheral oxygen saturation (SpO(2)) and end tidal carbon dioxide (EtCO(2)) during cataract surgery. MATERIALS AND METHODS: In total, 160 pre-medicated patients aged between 40 and 70 years (ASA I-III, classification of patients according to the American Society of Anesthesiologists) scheduled for cataract surgery under retrobulbar or peribulbar block were examined in a randomised, single-blind manner. The patients were sedated with 3 mg midazolam i.v. 15 min before operation and were monitored with an anaesthesia monitor. Heart rate (HR), non-invasive mean arterial pressure (MAP), SpO(2) and EtCO(2) were continuously measured using a standardised monitor. The first group (non-suction group, n = 80) received 4 L min(-1) O(2) with nasal cannule while the second group (suction group, n = 80) received 4 L min(-1) O(2) with nasal cannule, and the expired air was aspired with a Y-piece suction system. EtCO(2) was measured with the line of the sampling tube in the anaesthesia monitor. Respiratory rate (RR) was counted for a period of 1 min at each measurement time with thoracic excursions. The results were evaluated by unpaired t-test and analysis of variance. RESULTS: Severe reduction of SpO(2) and raising of EtCO(2) were observed significantly in the first group during the operation. RR, HR and MAP increased due to hypoxaemia. In the second group, SpO(2) was stabilised at high levels and EtCO(2) did not increase. RR, HR and MAP levels remained within the normal limits. Differences between the two groups were statistically significant (P < 0.05). CONCLUSION: During cataract surgery with local anaesthesia, SpO(2) decreases and RR, HR and MAP increase because of reinspiration of expired air under the drape. Insufflation of O(2) and aspiration of expired air with a suction system have prevented severe reduction of SpO(2) and raising of EtCO(2). It was suggested that O(2) delivery and use of an aspiration system decreased the risk of hypoxaemia significantly in the patients undergoing the cataract surgery.     

Visual experience during phacoemulsification cataract surgery under topical anaesthesia

BACKGROUND/AIMS: Visual awareness during phacoemulsification cataract surgery is an important determinant of patient satisfaction with any anaesthetic technique. Topical anaesthesia could be associated with significant visual awareness because it does not affect optic nerve function. METHODS: The visual experience during phacoemulsification cataract surgery under topical anaesthesia (without sedation) was assessed for 106 consecutive unselected patients. Patients were interviewed immediately after surgery using a standardised questionnaire that explored specific aspects of their visual experience. RESULTS: Four patients were excluded because they had poor recollection of their visual experience. The visual awareness of the remaining 102 patients comprised operating microscope light (99), colours (73), flashes of light (7), vague movements (19), surgical instruments or other objects (12), change in light brightness during surgery (49), change in colours during surgery (30), and transient visual alteration during corneal irrigation (25). No patient found their visual experience during surgery unpleasant, though the operating microscope light was uncomfortably bright for two patients. Six patients lost light perception for a short interval during surgery. There was no association between the various visual phenomena reported and patients' age, sex, preoperative visual acuity, cataract morphology, coexisting ocular pathology, or previous experience of cataract surgery under local anaesthesia (p>0.05). CONCLUSIONS: Patients experience a wide variety of visual sensations during phacoemulsification cataract surgery under topical anaesthesia. Topical anaesthesia does not, however, appear to result in greater visual awareness than regional anaesthesia. Preoperative patient counselling should include information about the visual experience during surgery.     

Local anaesthesia for vitreoretinal surgery: an audit of patient and surgical experience

PURPOSE: Local anaesthesia for vitreoretinal surgery is little used as these procedures are deemed to be too long and uncomfortable for patients to tolerate. In this unit anterior intraconal local anaesthesia is used for most routine surgery. We undertook an audit to ensure that surgical standards and patient acceptability were not compromised. METHODS: A prospective observational audit was performed. Audit data included: Grade of anaesthetist and surgeon; details of anaesthetic and operation; compliance of patient; operating conditions and pain scores. Anaesthesia was provided with a combined peribulbar and intraconal anaesthetic, using bicarbonate buffered lignocaine and bupivacaine 50:50 mixture. RESULTS: 135 (76%) had local anaesthesia alone, 13 (7%) had local anaesthesia with sedation and 29 (16%) had general anaesthesia. 96.4% of patients were compliant and 98.8% of operating conditions were good or excellent. The mean perioperative pain score was 0.1 (range of 0-1), 97% said they would choose local anaesthesia again. CONCLUSIONS: LA for vitreoretinal surgery is a useful and flexible method of anaesthesia, which has been shown to have excellent patient tolerance.     

Effect of midazolam on anxiety level and pain perception in cataract surgery with topical anesthesia

PURPOSE: To study the effect of sedation on patients' anxiety level and perception of pain during cataract surgery under topical anesthesia. SETTING: Royal Eye Infirmary, Plymouth, England. METHODS: This prospective controlled double-blind clinical trial comprised 100 consecutive patients having routine phacoemulsification with posterior chamber intraocular lens implantation under topical anesthesia by a single experienced surgeon. Patients were randomized to receive intravenous midazolam (0.015 mg/kg body weight) 15 minutes before surgery or no sedation. The main evaluation criteria were the anxiety based on the 6-item, short form of the State-Trait Anxiety Inventory, the pain score using a visual analog scale, and overall patient satisfaction. RESULTS: All operations were uneventful, and no side effects were noted from the use of midazolam. Anxiety scores were significantly higher on arrival at the hospital than just before the commencement and after the conclusion of the surgery in both groups (P<.05). Patients were less anxious after administration of midazolam, but this did not achieve statistical significance. The mean pain score was 0.29 (range 0 to 4) in the sedation group and 0.38 (range 0 to 4) in the control group; the difference between groups was not statistically significant. The patients were equally satisfied in both groups, with mean scores of 3.84 (range 0 to 4) and 3.88 (range 2 to 4), respectively. CONCLUSIONS: Patients who had cataract surgery under topical anesthesia were highly satisfied with their operative experience and reported minimal pain during surgery. Anxiety levels diminished after arrival at the hospital, possibly because of reassurance by experienced staff. Intravenous midazolam did not seem to significantly reduce pain or anxiety.     

Expanding role of local anaesthesia in vitreoretinal surgery

PURPOSE: Local anaesthesia (LA) is increasingly common in vitreoretinal surgery. However, younger patients often have such surgery under general anaesthesia (GA). We reanalysed the anaesthetic practice for vitreoretinal surgery in our unit over a 19-month period. METHODS: A total of 1003 patients undergoing vitreoretinal surgery between August 2000 and February 2002 were studied. Type of surgery, patient pain score to anaesthesia and surgery, need for sedation and incidence of complications related to the local anaesthetic were recorded. Comparisons were made between this case series and previous data from our unit. RESULTS: In total, 920/1003 (91.7%) patients had LA. Total operations comprised 418 vitrectomies, 518 retinopexies with or without vitrectomy and 67 buckling procedures. More patients under the age of 35 years had LA than previously (60.2 vs 35.7%, P<0.001). In 920/920 (100%) of cases, LA was administered via intraconal injection, compared to 164/1221 (13.4%) of procedures previously. Significantly more patients under the age of 35 years required sedation (35.9%) than did older patients (19.2%). Overall, use of sedation was significantly increased since our previous study (20.2 vs 7.8%). Anaesthesia and surgery were well tolerated by patients. There were no cases of orbital haemorrhage or ocular perforation. Complications included bradycardia requiring atropine 1/920 (0.1%) and chemosis 88/920 (9.6%). CONCLUSIONS: LA is well tolerated and effective even in younger patients. Sedation may well be required in younger patients and for procedures involving scleral buckling. The main indication for GA was patient preference. Despite this, such patients accounted for only 5.2% of the total.     

A survey of local anaesthesia use in cataract surgery in Australia

A survey of the use of local anaesthesia in cataract surgery by ophthalmologists in Australia is presented. The main conclusions drawn from the survey were: 1. A marked trend towards the use of local anaesthesia in cataract surgery during the years 1983–88 throughout Australia. A less marked trend in country areas and in Western Australia. 2. The use of local anaesthesia did not correlate with the number of cataract operations performed by an ophthalmologist. 3. Day case cataract surgery was more often performed under local anaesthesia in private than in public hospitals. 4. Throughout Australia retrobulbar local anaesthesia was preferred to the peribulbar technique. 5. The most commonly used local anaesthetic mixture was 2% lignocaine and 0.5% marcaine with or without adrenaline and/or hyalase.     

Is intracameral lidocaine really effective in cataract surgery?

PURPOSE: To evaluate the usefulness of intracameral lidocaine in cataract surgery under topical anesthesia and especially if the patient wanted intravenous sedation preoperatively. METHODS: In this prospective study 96 patients were randomly assigned to receive 0.5 cc of balanced salt solution (Group 1) or 1% unpreserved lidocaine (Group 2). Patients who wanted sedation received intravenous midazolam hydrochloride. All surgery was done by one surgeon using a clear corneal technique. RESULTS: Mean pain scores were 0.73 (of a maximum 3) in Group 1 and 0.54 in Group 2; the difference between groups was not statistically significant. Forty patients in Group 1 (83%) and 44 patients in Group 2 (92%) reported no discomfort or only mild discomfort. The two study groups were comparable in need for intravenous midazolam. Logistic regression analysis showed a significant relationship between pain scores and intravenous sedation (p=0.02) but not with intracameral lidocaine or other tested variables. However, odds ratio for pain increased to 5.1 (95% CI; 1.29-20.41) in participants without intravenous sedation compared to those with sedation. CONCLUSIONS: The results of the present study suggest that intravenous sedation preoperatively seems to be an important determinant to relieve the sensation of discomfort/pain during small incision cataract surgery, but intracameral lidocaine was shown not to have a clinically useful role.     

A survey of local anaesthesia use in cataract surgery in Australia

A survey of the use of local anaesthesia in cataract surgery by ophthalmologists in Australia is presented. The main conclusions drawn from the survey were: 1. A marked trend towards the use of local anaesthesia in cataract surgery during the years 1983-88 throughout Australia. A less marked trend in country areas and in Western Australia. 2. The use of local anaesthesia did not correlate with the number of cataract operations performed by an ophthalmologist. 3. Day case cataract surgery was more often performed under local anaesthesia in private than in public hospitals. 4. Throughout Australia retrobulbar local anaesthesia was preferred to the peribulbar technique. 5. The most commonly used local anaesthetic mixture was 2% lignocaine and 0.5% marcaine with or without adrenaline and/or hyalase.     

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 preopera-tive 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.     

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.     

Effectiveness of local anaesthesia for external dacryocystorhinostomy

Purpose: To establish the effectiveness, complications and patient acceptance of local anaesthesia (LA) with intra‐venous sedation, for external dacryocystorhinostomy (DCR). Methods: Data were prospectively collected over a 4‐year period (1997?2000) on all patients undergoing external DCR under LA with intravenous sedation by one surgeon and one anaesthetist, using a standardized technique. Results: Of 183 DCR procedures, 145 (76.5%) were performed using LA in 123 patients aged 24?84 years (median 64 years). Eleven simultaneous bilateral DCR procedures were performed under LA. Another 11 patients had a contralateral DCR at a later date. In only three DCR (2.1%) was supplementation of LA required during the procedure because of pain. The only complication of the technique was one retrobulbar haemorrhage from the medial peribulbar injection. In this patient, the procedure was completed satisfactorily without further sequelae. All patients found the technique acceptable and all 11 patients who returned for surgery on the opposite side at a later date elected to have surgery under LA again. Conclusions: External DCR can be satisfactorily and safely performed under LA with a high level of patient acceptance.     

Ropivacaine versus lidocaine for deep-topical, nerve-block anaesthesia in cataract surgery: a double-blind randomized clinical trial

PURPOSE: To evaluate the safety and efficacy of ropivacaine versus lidocaine for deep-topical, nerve-block anaesthesia in cataract surgery. METHODS: This prospective controlled randomized double-blind study comprised 64 patients undergoing clear corneal phacoemulsification. Patients were equally divided into two group receiving either deep-topical anaesthesia with 1% ropivacaine-soaked sponge (Group R, n = 32) or 2% lidocaine-soaked sponge (Group L, n = 32). The level of intraoperative and postoperative pain was assessed by patients using a verbal analogue scale from 1 to 10. The duration of surgery, the need for supplemental anaesthesia, surgeon satisfaction, and intraoperative and early postoperative complications were recorded. The patients' heart rate, arterial blood pressure and peripheric oxygen saturation (SpO(2)) were obtained just before the anaesthesia and during the surgery. RESULTS: The demographic data of the patients and duration of surgery were similar in both groups. No significant difference in the mean pain scores of patients were found in the ropivacaine and lidocaine groups. Surgical satisfaction was also statistically insignificant. None of the patients had significant difference in heart rate, blood pressure or SpO(2) during the surgical procedure. CONCLUSION: Deep-topical anaesthesia with ropivacaine and lidocaine in cataract surgery is safe and the two anaesthetic agents do not present differences in the degree of analgesia achieved. Deep-topical anaesthesia with ropivacaine or lidocaine was equally effective in providing anaesthesia with sufficient quality for cataract surgery.     

Anaesthesia techniques for cataract surgery: a survey of delegates to the Congress of the International Council of Ophthalmology, 2002

BACKGROUND: Cataract surgery is performed using various regional, local, or topical anaesthetic techniques and agents and general anaesthesia. As there is continuous change in the popularity of these techniques, an estimate of current anaesthetic practices for cataract surgery around the world was derived. This allows comparison of techniques and practices internationally and may serve as a baseline for future surveys. METHODS: At the 2002 Congress of the International Council of Ophthalmology held in Sydney, Australia, ophthalmic surgeons from around the world were surveyed with regard to their anaesthetic techniques for cataract surgery. RESULTS: It was found that almost all cataract surgery was performed using regional anaesthesia. Surgeons performed just over half of the anaesthetics; however, in some countries anaesthetists performed the vast majority of eye anaesthetics. The most frequently employed technique was the peribulbar block, but a substantial minority were performed under topical anaesthesia. An anaesthesia-trained person monitored most patients during cataract surgery, and the most commonly used local anaesthetic was lignocaine. CONCLUSION: Although there is a single most frequent practice in the type of regional block employed for cataract surgery among the delegates, and general anaesthesia is seldom used, individual countries have very different results regarding the anaesthetic used and the role of the anaesthetist.     

Intraocular pressure and pulsatile ocular blood flow after retrobulbar and peribulbar anaesthesia

AIMS: This study investigated the effect of peribulbar and retrobulbar local anaesthesia on intraocular pressure (IOP) and pulsatile ocular blood flow (POBF), as such anaesthetic techniques may adversely affect these parameters. METHODS: 20 eyes of 20 patients who were to undergo phacoemulsification cataract surgery were prospectively randomised to receive peribulbar or retrobulbar anaesthesia. The OBF tonometer (OBF Labs, Wiltshire, UK) was used to simultaneously measure IOP and POBF before anaesthesia and 1 minute and 10 minutes after anaesthesia. Between group comparisons of age, baseline IOP, and baseline POBF were performed using the non-parametric Mann-Whitney test. Within group comparisons of IOP and POBF measured preanaesthesia and post-anaesthesia were performed using the non-parametric Wilcoxon signed ranks test for both groups. RESULTS: There was no statistically significant IOP increase post-anaesthesia in either group. In the group receiving peribulbar anaesthesia, there was a significant reduction in POBF initially post-anaesthesia which recovered after 10 minutes. In the group receiving retrobulbar anaesthesia, there was a persistent statistically significant reduction in POBF. CONCLUSIONS: Retrobulbar and peribulbar injections have little effect on IOP. Ocular compression is not needed for IOP reduction when using local anaesthesia for cataract surgery. Conversely, POBF falls, at least for a short time, when anaesthesia for ophthalmic surgery is administered via a retrobulbar route or a peribulbar route. This reduction may be mediated by pharmacologically altered orbital vascular tone. It may be safer to use other anaesthetic techniques in patients with ocular vascular compromise.