Retrobulbar anesthesia and retinal vascular obstruction

Retinal artery occlusion after ophthalmic surgery under regional anaesthesia: A narrative review

Two recent cases of central retinal artery occlusion under otherwise uncomplicated sub-Tenon's block that resulted in significant visual loss after cataract surgery prompted us to undertake a literature review of such cases. We identified 97 cases of retinal artery occlusion after ophthalmic surgery under regional anaesthesia that had no immediate signs of block-related complications. These occurred after various intraocular (87%) and extraocular (13%) operations, across a wide range of ages (19-89 years) on patients with (59%) or without (39%) known risk factors. The anaesthetic techniques included 40 retrobulbar blocks, 36 peribulbar blocks, 19 sub-Tenon's blocks, one topical anaesthetic and one unspecified local anaesthetic. Different strengths of lidocaine, bupivacaine, mepivacaine and ropivacaine, either alone or in various combinations, were used. The details of the anaesthetic techniques were often incomplete in the reports, which made comparison and analysis difficult. Only nine cases had their cause (optic nerve sheath injury) identified, while the mechanism of injury was unclear in the remaining patients. Various mechanisms were postulated; however, the cause was likely to be multifactorial due to patient, surgical and anaesthetic risk factors, especially in those with compromised retinal circulation. As there were no definite risk factors identified, no specific recommendations could be made to avoid this devastating outcome. We have provided rationales for some general considerations, which may reduce this risk, and propose anaesthetic options for ophthalmic surgery on the fellow eye if required, based both on our literature review and our personal experience.

Iatrogenic central retinal artery occlusion following retrobulbar anesthesia with adrenaline for vitreoretinal surgery: a case report

BACKGROUND

We describe a patient presenting with central retinal artery occlusion (CRAO) of the right eye after retrobulbar anesthesia with adrenaline for macular pucker surgery.

CASE PRESENTATION

The patient, a 67-year-old Caucasian man, developed a CRAO postoperatively by the next-day control likely due to the retrobulbar injection of a combination of Xylocaine and Bupivacaine with adrenaline as anesthetic.

CONCLUSIONS

The addition of adrenaline to the standard anesthetic solution could be a risk factor for serious complications, such as CRAO.

Regional Anesthesia for Pediatric Ophthalmic Surgery: A Review of the Literature

Ophthalmic pediatric regional anesthesia has been widely described, but infrequently used. This review summarizes the available evidence supporting the use of conduction anesthesia in pediatric ophthalmic surgery. Key anatomic differences in axial length, intraocular pressure, and available orbital space between young children and adults impact conduct of ophthalmic regional anesthesia. The eye is near adult size at birth and completes its growth rapidly while the orbit does not. This results in significantly diminished extraocular orbital volumes for local anesthetic deposition. Needle-based blocks are categorized by relation of the needle to the extraocular muscle cone (ie, intraconal or extraconal) and in the cannula-based block, by description of the potential space deep to the Tenon capsule. In children, blocks are placed after induction of anesthesia by a pediatric anesthesiologist or ophthalmologist, via anatomic landmarks or under ultrasonography. Ocular conduction anesthesia confers several advantages for eye surgery including analgesia, akinesia, ablation of the oculocardiac reflex, and reduction of postoperative nausea and vomiting. Short (16 mm), blunt-tip needles are preferred because of altered globe-to-orbit ratios in children. Soft-tip cannulae of varying length have been demonstrated as safe in sub-Tenon blockade. Ultrasound technology facilitates direct, real-time visualization of needle position and local anesthetic spread and reduces inadvertent intraconal needle placement. The developing eye is vulnerable to thermal and mechanical insults, so ocular-rated transducers are mandated. The adjuvant hyaluronidase improves ocular akinesia, decreases local anesthetic dosage requirements, and improves initial block success; meanwhile, dexmedetomidine increases local anesthetic potency and prolongs duration of analgesia without an increase in adverse events. Intraconal blockade is a relative contraindication in neonates and infants, retinoblastoma surgery, and in the presence of posterior staphylomas and buphthalmos. Specific considerations include pertinent pediatric ophthalmologic topics, block placement in the syndromic child, and potential adverse effects associated with each technique. Recommendations based on our experience at a busy academic ophthalmologic tertiary referral center are provided.

The entry point of the central retinal artery into the outer meningeal sheath of the optic nerve

INTRODUCTION

The entry point of the central retinal artery (CRA) into the outer meningeal sheath of the optic nerve posterior to the globe has been studied and debated for more than one hundred years. The authors have supervised an orbital anatomy course for more than two decades. This article summarizes previous studies of the CRA and presents the results of dissections of 67 orbits.

MATERIALS AND METHODS

Heads were hemisected prior to dissection at the Vagelos College of Physicians and Surgeons of Columbia University. The authors measured the entry point of the CRA with a caliper and noted the meridional orientation of the CRA.

RESULTS

The mean entry point was 10.65 mm posterior to the globe, with a range of 5 to 18 mm. Most commonly, the CRA entered the sheath in the inferior meridian, but some entered slightly inferomedially or inferolaterally.

CONCLUSIONS

The entry point of the CRA into the sheath of the optic nerve is variable, and without detailed angiography the clinician cannot know the course of the CRA prior to performing invasive intraorbital procedures. Knowledge of common variations in CRA entry into the outer meningeal sheath of the optic nerve should help to minimize injury during surgery.

Iatrogenic ophthalmic artery occlusion and retinal artery occlusion

Iatrogenic ophthalmic artery occlusion (IOAO) is a rare but devastating ophthalmic disease that may cause sudden and permanent visual loss. Understanding the possible etiologic modalities and pathogenic mechanisms of IOAO may prevent its occurrence. There are numerous medical etiologies of IOAO, including cosmetic facial filler injection, intravascular procedures, intravitreal gas or drug injection, retrobulbar anesthesia, intraarterial chemotherapy in retinoblastoma. Non-ocular surgeries and vascular events in arteries that are not directly associated with the ophthalmic artery, can also cause IOAO. Since IOAO has a limited number of treatment modalities, which lead to poor final visual prognosis, it is imperative to acknowledge the information regarding medical procedures that are etiologically associated with IOAO. We accumulated all searchable and available IOAO case reports (our cases and previous reported cases from the literature), classified them according to their mechanisms of pathogenesis, and summarized treatment options and responses of each of the causes. Various sporadic cases of IOAO can be categorized into three mechanisms as follows: intravascular event, orbital compartment syndrome, and increased intraocular pressure. Embolic IOAO, which is considered the primary cause of the condition, was classified into three subgroups according to the pathway of embolic movement (retrograde pathway, anterograde pathway, pathway through collateral channels). Despite the practical limitations of treating spontaneous (non-iatrogenic) retinal artery occlusion, this article will contribute in predicting and improving the prognosis of IOAO by recognizing the treatable factors. Furthermore, it is expected to provide clues to future research associated with the treatment of retinal artery occlusion.

Perioperative considerations and anesthesia management in patients with obstructive sleep apnea undergoing ophthalmic surgery

Obstructive sleep apnea (OSA) is a disorder characterized by breathing cessation caused by obstruction of the upper airway during sleep. It is associated with multiorgan comorbidities such as obesity, hypertension, heart failure, arrhythmias, diabetes mellitus, and stroke. Patients with OSA have an increased prevalence of ophthalmic disorders such as cataract, glaucoma, central serous retinopathy (detachment of retina, macular hole), eyelid laxity, keratoconus, and nonarteritic anterior ischemic optic neuropathy; and some might require surgery. Given that OSA is associated with a high incidence of perioperative complications and more than 80% of surgical patients with OSA are unrecognized, all surgical patients should be screened for OSA (eg, STOP-Bang questionnaire) with comorbidities identified. Patients suspected or diagnosed with OSA scheduled for ophthalmic surgery should have their comorbid conditions optimized. This article includes a review of the literature and highlights best perioperative anesthesia practices in the management of ophthalmic surgical patients with OSA.

Optical Coherence Tomography Angiography of Combined Central Retinal Artery and Vein Occlusion

Optical coherence tomography angiography (OCTA) is a new, noninvasive technology that enables detailed evaluation of flow in the retinal and choroidal vasculature. The authors believe this to be the first report to describe the optical coherence tomography angiography findings associated with combined central retinal artery occlusion (CRAO) and central retinal vein occlusion (CRVO).

Subconjunctival hemorrhage and vision loss after regional ocular anesthesia

PURPOSE

To report two cases of retinal vascular occlusion and associated subconjunctival hemorrhage in needle optic nerve injury during local bulbar anesthesia.

METHODS

Surgical records of these two subjects who presented with acute vision loss after cataract extraction were studied, and systemic workup and ocular imaging were carried out to establish the cause.

RESULTS

Computerized tomography showed evidence of optic nerve injury.

CONCLUSION

Subconjunctival hemorrhage could be an associated clinical finding in hypodermic needle injury-related retinal vascular occlusion during ocular anesthesia.

Traumatic Branch Retinal Vein Occlusion With Retinal Neovascularization Following Inadvertent Retrobulbar Needle Perforation

Retrobulbar injection of anesthesia is one of the most common procedures performed for ophthalmic surgery. Complications are rare but can be potentially serious, including retrobulbar hemorrhage, brainstem anesthesia, and inadvertent globe perforation. This is the preliminary report describing branch retinal vein occlusion (BRVO) secondary to accidental retrobulbar needle laceration with subsequent preretinal neovascularization.

Profound vascular stasis of retina and optic nerve following retrobulbar anesthesia

INTRODUCTION

We aim to describe a mechanism of vision loss following vitrectomy surgery with retrobulbar block (RBB) associated with severe vascular stasis of the optic nerve and macula in order to improve safety of local anesthesia for ophthalmic surgery.

CASE PRESENTATION

We report three cases of patients who underwent pars plana vitrectomy (PPV) with retrobulbar anesthesia with no retrobulbar hemorrhage or elevated intraocular pressure (IOP). At the beginning, in each case, hypoperfusion of optic nerve and macula was noted. In the case of one patient with significant vasculopathic risk factors, the vascular stasis was severe, while in the other two cases, it was mild-to-moderate. In all cases, the perfusion of posterior pole began to improve almost immediately following the start of PPV. Because the IOP was not elevated and no retrobulbar hemorrhage was present, this suggested a compartment syndrome in the intraconal space. The patient with severe vascular stasis developed finger-counting vision but had normal postoperative angiogram findings and unrevealing cardiovascular workup. In the other two milder cases, the occurrence of ischemia was not visually significant.

CONCLUSION

Intraoperative ischemia should be considered in all cases of unexplained vision loss after ophthalmic surgery using RBB. Attention to vasculopathic risk factors and intra-operative hemodynamic parameters, in addition to the use of parabulbar block, may avoid this complication and permanent vision loss.

Iatrogenic Central Retinal Artery Occlusion Following Retrobulbar Anesthesia for Intraocular Surgery

Purpose

To present clinical features of central retinal artery occlusion (CRAO) following retrobulbar anesthesia for intraocular surgery.

Methods

This observational case series describes 5 consecutive patients with acute CRAO following retrobulbar anesthesia for intraocular surgery. Data collected for this study included subject characteristics, retrobulbar anesthesia technique, treatment type, initial and final best-corrected visual acuity, and other ophthalmologic examinations.

Results

Mean subject age was 67.0 ± 8.2 years (range, 53 to 72 years). All patients had one or more vascular risk factors (e.g., hypertension, cerebral infarction, carotid artery stenosis) and presented with acute vision loss 1 day after uneventful intraocular surgery (cataract surgery in 2 eyes and vitrectomy in 3 eyes). All 5 patients received retrobulbar anesthesia during surgery, 4 of which involved the use of a sharp needle. No immediate complications were noted during intraocular surgery. Final visual prognosis was poor (from finger count to no light perception) although intraocular thrombolysis was attempted in 3 patients.

Conclusions

Iatrogenic CRAO is a potential complication of retrobulbar anesthesia for intraocular surgery in elderly patients with vascular risk factors. Unfortunately, this complication can lead to severe vision loss. We conclude that retrobulbar anesthesia for intraocular surgery should be performed with great care and special consideration for elderly patients with vascular risk factors.

Optic neuropathy following retrobulbar injection: a review

A retrobulbar block is a regional anesthetic nerve block in the retrobulbar space. Optic neuropathy following retrobulbar injection is a well-recognized and rare complication of the procedure with an unknown incidence. This article reviews the relevant literature regarding vision loss following this procedure. Mechanisms of injury to the optic nerve as well as methods that can be employed to minimize the risk of optic neuropathy will be explored, including alternatives to retrobulbar anesthesia.

Central retinal artery occlusion after phacoemulsification

PURPOSE

To report 2 cases of central retinal artery occlusion (CRAO) that occurred within 24 hours of routine phacoemulsification cataract surgery using peribulbar anesthesia.

METHODS

Case 1: An otherwise well 76-year-old woman with right pseudoexfoliation syndrome and bilateral open angle glaucoma presented with right visual acuity of counting fingers on the first postoperative day after cataract surgery. The CRAO was noted on fundoscopy. Emergency measures to reduce intraocular pressure (IOP) and hyperbaric oxygen treatment were performed. Case 2: A 59-year-old man with a history of non-Hodgkin's lymphoma, hypertension, hyperlipidemia, and ischemic stroke was similarly diagnosed with CRAO on the first postoperative day, with left visual acuity of counting fingers.

RESULTS

The final visual acuity remained at counting fingers in both cases.

CONCLUSION

Central retinal artery occlusion after routine cataract surgery is unusual. We review the literature on CRAO after routine intraocular procedures and propose three hypotheses regarding the potential mechanisms involved. A vasoconstrictive effect of the anesthetic agent on the central retinal artery, a rise in lOPs after anesthesia administration resulting in closure of the central retinal artery, and a mechanical effect of the volume of anesthetic on the central retinal artery are considered as plausible mechanisms, with a mechanical effect being the favored hypothesis.

Topical anesthesia for cataract surgery: the patients' perspective

Purpose. To evaluate the analgesic efficacy of 0.5% propacaine hydrochloride as topical anesthesia during phacoemulsification surgery. Methods. Intraoperative pain intensity was assessed using a 5-category verbal rating scale during each of three surgical stages. Pain scores from each surgical stage and total pain scores were compared for the factors of patient age, gender, cataract laterality, and type. Results. In comparison of cataract type subgroups, the mean total pain scores and mean stage 2 pain scores in both white mature cataract (WMC) and corticonuclear plus posterior subcapsular cataract (CN + PSC) groups were significantly higher than in the PSC-only (PSC) group (P < 0.05). Conclusion. Phacoemulsification with topical anesthesia is not a completely painless procedure. Pain intensity varies with cataract type and stage of surgery.

Comorbidities in combined retinal artery and vein occlusions

Background

Several general diseases cause blindness in patients with simultaneous combined retinal artery and vein occlusion.

Methods/patients

We examined 14 patients with acute unilateral visual loss due to combined retinal artery and venous occlusions. All 14 patients presented at the Polyclinic over a period of about 3 years. Fluorescein angiography was carried out in 12 patients to confirm the diagnosis. Ten patients underwent Doppler sonography and 11 echocardiography.

Results

Concerning systemic diseases, 11 of our 14 patients presented several cardiovascular risk factors, i.e., immunocytoma and arterial hypertension and hypercholesterolemia in one patient; another patient had chronic bronchitis, tachycardia and hypercholesterolemia. Six patients presented coagulation anomalies, and eight patients had arterial hypertension.

Doppler sonography revealed normal carotid arteries in nine of ten patients. In 8 of 11 patients, echocardiography displayed no cardiac abnormalities.

Ophthalmoscopy revealed no emboli in any of these patients.

Conclusion

Unilateral simultaneous combined incomplete retinal artery and venous occlusions should be considered as one entity. Eleven of our patients presented comorbidities reflecting several cardiovascular risk factors. Immunological diseases, malignancies and coagulopathies can cause this ocular disorder, resulting in blindness. No emboli were found in any of these patients. Patients suffering from acute visual loss must be examined for the presence of systemic diseases to enable therapy at an early stage.

Comparing remifentanil versus propofol effect on pain and homodynamic change of patients undergoing phacoemulsification with topical anesthesia

Introduction

The purpose of this study was to compare remifentanil versus propofol effect on pain and homodynamic in patients undergoing phacoemulsification with topical anesthesia.

Materials and Methods

A double blind clinical trial was conducted to research following the approval of the ethical committee research of the university. One hundred volunteer subjects were randomly assigned into two equal groups (n = 50). The subjects in the propofol group received 3mg/kg/hr while the patients in the remifentanil drug received 3 µg/kg/hr of this medication. Phaco time, blood pressure and heart rate before and after surgery, respiratory depression (O2 sat < 90%) and vomiting, pain scores, ophthalmologist satisfaction and demographic data were recorded.

Results

The results of analysis showed that there were no significant differences between the age, sex, and duration of operation of the two treatment groups. Systolic, diastolic blood pressure and heart rate were significantly lower in the propofol group .The propofol group complained of pain than the remifentanil group (P = 0.001) while the surgeon satisfaction was higher for the remifentanil condition (P = 0.01). No significant differences were found between the two groups with respect to respiratory depression .No patient suffered from nausea and vomiting.

Conclusions

The results of this study indicated that using appropriate dose of remifentanil instead of propofol results in less pain, more stable homodynamic condition, and satisfaction of surgeon without no respiratory depression or perioperative nausea and vomiting.

Acute Visual Field Defect following Vitrectomy Determined to Originate from Optic Nerve by Electrophysiological Tests

Purpose

To present our findings on the cause of an acute visual field defect (VFD) that developed in a patient on the day after vitrectomy for proliferative diabetic retinopathy.

Case

A 50-year-old man complained of a blind area in the superior visual field that developed one day after vitrectomy. The patient had undergone uncomplicated vitrectomy for a long-duration vitreous hemorrhage associated with proliferative diabetic retinopathy. Residual vitreous hemorrhage hampered a clear view of the fundus. Goldmann perimetry showed a horizontal VFD in the superior field. The area corresponding to the VFD was examined by multifocal electroretinograms (mfERGs) and multifocal visual evoked potentials (mfVEPs). The amplitudes of the mfVEPs were reduced with prolonged implicit times especially when the superior hemifield was stimulated, while the amplitudes and implicit times were within the normal range when other parts of the visual field were stimulated. In addition, the full-field photopic ERGs and photopic negative responses were attenuated in the right eye. These findings suggested that the VFD did not originate from alterations in the retinal inner and middle layer but in the ganglion cells. The visual acuity improved to 1.2 but his optic disc became pale and the VFD remained unchanged more than 12 years after the surgery.

Conclusion

We suggest that vitrectomy can cause ischemic optic neuropathy by interfering with the circulation associated with diabetes mellitus. Evaluations by mfERGs, mfVEPs, and full-field photopic ERGs were helpful in making the diagnosis.

Unanticipated vision loss after pars plana vitrectomy

Although advances in vitreoretinal surgical techniques and technology have helped to minimize the risks associated with surgical manipulation of the retina, retinal pigment epithelium, and optic nerve, unanticipated or unexplained visual loss still occurs. We review causes of vision loss encountered after pars plana vitrectomy, including retinal toxicities, vascular events, and optic neuropathies, and we suggest strategies to limit or prevent them.

Comparison of sedative drugs under peribulbar or topical anesthesia during phacoemulsification

BACKGROUND AND OBJECTIVE

To compare dexmedetomidine and midazolam+fentanyl sedation primarily based on patient satisfaction during phacoemulsification under topical and peribulbar anesthesia.

PATIENTS AND METHODS

Prospective, randomized, and double-blind study of 80 American Society of Anesthesiology grade I-II patients who underwent phacoemulsification with local anesthesia under sedation. Patients were divided into four groups (20 patients for each): dexmedetomidine and topical anesthesia, dexmedetomidine and peribulbar anesthesia, midazolam+fentanyl and topical anesthesia, and midazolam+fentanyl and peribulbar anesthesia. Patient and surgeon satisfaction were determined on a 5-point scale. The pain was determined by verbal pain scale intraoperatively and postoperatively. Drugs were given to a Ramsay sedation scale of 3. Topical and peribulbar anesthesia were performed by an ophthalmologist. Hemodynamic, respiratory, and intraocular pressure monitoring was done. Operative and recovery times were recorded.

RESULTS

In the midazolam+fentanyl groups, better patient and surgeon satisfaction scores were obtained (P < .005), verbal pain scale scores were significantly lower (P < .001), and patients needed less postoperative analgesia. Ramsay sedation scale scores were between 3 and 4 in all patients and there were no significant differences. Intraocular pressure alterations were similar between groups. Recovery time was longer in the dexmedetomidine groups (P < .05).

CONCLUSION

The study demonstrated that the midazolam+fentanyl combination provided high-level patient satisfaction scores, low-level pain scores, and shorter recovery time. Also, both of the peribulbar and topical anesthesia procedures showed similar efficiency.

[Safety of "needle" regional anaesthesia for anterior segment surgery under antiplatelet agents and anticoagulants therapies]

INTRODUCTION

cataracts preferentially affect the elderly. More than 560,000 procedures are performed annually in France on vulnerable patients that are exposed to cardio-circulatory conditions requiring antiplatelet and/or anticoagulants. Haemorrhagic complications resulting from cataract surgery and/or eye regional anaesthesia are rare but can lead to serious damage to eye function.

PATIENTS AND METHODS

in this study, we compared the management care of two types of antiplatelet and/or anticoagulants successively utilizing the following procedure: first, the cessation of antiplatelet agents and anticoagulants were relayed with rapid elimination agents (constituting our reference "before" cohort [November 2004-May 2005]), then the antiplatelet or anticoagulant management was continued without stint according to recent data from literature (constituting our "after" cohort (April 2007-March 2008)).

RESULTS

a reference population, consisting of 229 patients, was operated on exclusively with "surgical" sub-Tenon's anaesthesia. A second group, consisting of 178 patients, was operated on using "needle" regional anaesthesia. In both populations, nearly 33% of patients received antiplatelet or anticoagulant treatment. The incidence of subconjonctival haemorrhage occurred more frequently when anticoagulants agents were relayed (33% vs 0%; P<0,05), but there was no significant difference with antiplatelet agents (23% vs 8%; NS). The most common non-bleeding event was Chemosis and related to the type of anaesthetic technique utilized, although not serious it tended to jeopardize surgical comfort (anticoagulants: 35% vs 36% (NS), antiplatelet agents: 38% vs 40%; NS).

CONCLUSION

the technical changes do not explain fully that occurrence of the HSC, in patients under anticoagulant treatment, decreased in the second period. The achievement of "needle" regional anaesthesia in the anterior segment eye surgery is a safe technique that does not require stopping antiplatelet treatment or anticoagulation.

The operation was a success, but the patient cannot see

A 71-year-old African American woman presented with severe vision loss in her left eye one day following trabeculectomy with mitomycin C and retrobulbar anesthesia. She had a new left relative afferent pupillary defect and macular whitening. The optic disc appeared normal. Intraocular pressure and fluorescein angiography were normal. Westergren erythrocyte sedimentation rate and C-reactive protein were elevated. Temporal artery biopsy was positive for giant cell arteritis.

Side effects of postoperative administration of methylprednisolone and gentamicin into the posterior sub-Tenon's space

PURPOSE

To assess the incidence of postoperative emetic side effects after the administration of methylprednisolone and gentamicin into the posterior sub-Tenon's space at the end of routine cataract surgery.

SETTING

St. Luke's Hospital, Gwardamangia, Malta.

METHODS

A double-blind double-armed prospective study comprised 40 patients who had uneventful sutureless phacoemulsification under sub-Tenon's local infiltration of 3 mL of plain lignocaine. At the end of the procedure, Group A (n = 20) had 20 mg/0.5 mL of methylprednisolone and 10 mg/0.5 mL of gentamicin injected into the posterior sub-Tenon's space and Group B (n = 20) had the same combination injected into the anterior sub-Tenon's space. Postoperatively, all patients were assessed for symptoms of nausea, vomiting, and headache. A chi-square test was used to assess the statistical significance of results.

RESULTS

Sixty percent in Group A developed postoperative emetic symptoms, headache, or both; 1 patient in Group B developed symptoms.

CONCLUSIONS

The administration of methylprednisolone and gentamicin in the posterior sub-Tenon's space was related to a high incidence of side effects including nausea, vomiting, and headache. All adverse effects were self-limiting.

Subtenon lidocaine vs topical proparacaine in adult strabismus surgery

Intraoperative subtenon 2% lidocaine and topical 0.5% proparacaine in patients undergoing strabismus surgery were compared. No additional systemic analgesics and sedatives were used. Mean and total pain scores intraoperatively and postoperatively were not different. Each anesthetic agent provides good intraoperative anesthesia and postoperative analgesia. Topical 0.5% proparacaine may be preferred because of its easy administration and fewer side effects, lack of hospital admission, and immediate and predictable alignment of the eyes.

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

PURPOSE

To assess the safety and efficacy of phacoemulsification under a topical anesthesia combined with intracameral lidocaine 0.5%.

SETTING

Department of Ophthalmology, Chang Gung Memorial Hospital, Taoyuan, Taiwan, China.

METHODS

A prospective randomized double-blind study was designed in which patients had phacoemulsification performed under topical anesthesia (4 drops of nonpreserved lidocaine 2%) with 0.15 mL intracameral placebo (balanced salt solution) in 1 eye (Group 1) and topical anesthesia with intracameral nonpreserved lidocaine 0.5% in the other eye (Group 2). Endothelial changes, including cell density, coefficient variation of cell size, and percentage of hexagonal cells, were measured by noncontact specular microscopy. Preoperative and postoperative best corrected visual acuity was also documented. The degree of pain throughout surgery was ranked on a 10-point visual analog pain scale.

RESULTS

Thirty-three patients were recruited. There was no significant difference in preoperative and postoperative mean endothelial parameters between the 2 groups. Furthermore, mean endothelial cell loss was similar. Mild or no pain (score 0 to 1) was reported by 48.5% in Group 1 and 90.9% in Group 2. Patients reported less pain with combined topical and intracameral lidocaine anesthesia (P = .001, Mann-Whitney test). Vision was significantly improved in both groups. However, 1 patient in Group A developed vitreous loss as a result of involuntary eye movement.

CONCLUSION

Combining topical anesthesia with intracameral lidocaine 0.5% [corrected] anesthesia was safe and effective in phacoemulsification with intraocular lens implantation.

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.

Prospective study comparing lidocaine 2% jelly versus sub-Tenon's anaesthesia for trabeculectomy surgery

AIMS

To compare the analgesic properties of lidocaine 2% jelly versus sub-Tenon's anaesthesia with lidocaine 2% without adrenaline (epinephrine) for trabeculectomy surgery.

METHODS

A prospective randomised clinical trial. 59 consecutive patients scheduled for trabeculectomy at the Toronto Western Hospital were randomly assigned to topical unpreserved lidocaine 2% jelly or sub-Tenon's anaesthesia with 2% lidocaine. Both groups received a standardised sedative consisting of midazolam, fentanyl. and/or propofol. The visual analogue scale was utilised to measure intraoperative pain. Patient comfort, physician assessment of intraoperative patient compliance, volume of local anaesthetic used, need for supplemental anaesthesia, and any complications were recorded. The two groups were compared using the Student's t test.

RESULTS

The sub-Tenon's anaesthesia group and the lidocaine 2% jelly group did not vary significantly in subjective pain score (18.3 (SD 16.2) v 19.8 (12.4) respectively, p = 0.739) and surgeons' satisfaction scale (3.6 (0.7) and 3.8 (0.6) respectively, p = 0.328). Four patients required additional anaesthesia, all of them in the sub-Tenon's group.

CONCLUSION

Topical lidocaine 2% jelly is as effective as sub-Tenon's anaesthesia for pain control in patients undergoing trabeculectomy. Lidocaine 2% jelly is similar to sub-Tenon's anaesthesia in patient comfort and surgeon satisfaction.

Comparative clinical trial of topical anesthetic agents in cataract surgery

PURPOSE

To assess the efficacy of lidocaine gel, bupivacaine drops, and benoxinate drops as topical anesthetic agents in cataract surgery.

SETTING

Kasr El-Aini Hospital, Cairo University, Cairo, Egypt.

METHODS

This prospective randomized study comprised 90 patients scheduled for routine cataract extraction. Patients were randomized into 3 groups of 30 each based on which anesthetic agent they received: lidocaine 2% gel, bupivacaine 0.5% drops, or benoxinate 0.4% drops. Subjective pain at application of the agent and intraoperatively was quantified by the patients using a verbal pain score (VPS) scale from 0 to 10. The duration of discomfort at application, duration of surgery, rate of supplemental sub-Tenon's anesthesia, and complications were recorded.

RESULTS

The mean VPS at application was 2.97, 1.53, and 1.03 in the lidocaine, bupivacaine, and benoxinate groups, respectively; the VPS in the lidocaine group was statistically significantly higher than in the other 2 groups (P<.001). The mean duration of pain at application was 25 seconds, 14 seconds, and 6 seconds in the lidocaine, bupivacaine, and benoxinate groups, respectively, and was statistically significantly higher in the lidocaine group (P<.001). The mean VPS during surgery was 1.6, 4.1, and 7.1 in the lidocaine, bupivacaine, and benoxinate groups; the lidocaine group had a statistically significantly lower mean VPS than the other 2 groups (P<.001). The incidence of supplemental sub-Tenon's injection was 3.3%, 10.0%, and 73.3%, respectively, and was statistically significantly lower in the lidocaine and bupivacaine groups than in the benoxinate group (P<.001). The patients' overall satisfaction was statistically significantly higher in the lidocaine and bupivacaine groups than in the benoxinate group (93.3%, 83.3%, and 33.3%, respectively) (P<.001). Three patients in the lidocaine group had corneal haze at the time of surgery, which was not statistically significant (P>.1).

CONCLUSIONS

Lidocaine gel was a better topical anesthetic agent than bupivacaine and benoxinate drops. Bupivacaine drops were effective in providing deep topical anesthesia.

Combined Topical and Intracameral Anesthesia in Penetrating Keratoplasty

BACKGROUND

The standard of care for penetrating keratoplasty (PKP) is either retrobulbar or peribulbar anesthesia combined with seventh cranial nerve akinesia or general anesthesia. These methods are known to be associated with rare but potentially serious adverse ocular and systemic events.

PURPOSE

To determine the safety and efficacy of combined topical and intracameral anesthesia in addition to intravenous sedation for repeat penetrating keratoplasty (PKP).

SETTING

Tertiary-care university hospital.

METHODS

In this prospective study, combined topical tetracaine 0.5% and 0.2 cc intracameral 1% lidocaine along with i.v. sedation with midazolam and fentanyl were used for patients undergoing repeat PKP in 15 eyes of 15 selected patients. The indication for surgery was failed corneal graft. Verbal pain scale (VPS, 0-3) was recorded preoperatively, intraoperatively at 3 time-points (after trephination, after placing 8 interrupted sutures, and after placing the running suture), and postoperatively (1 hour postoperatively, overnight pain, and 1 day postoperatively). Patient and surgeon satisfaction were assessed postoperatively using a scale (1-5). After surgery patients were asked for their preferences comparing the current use of topical anesthesia compared with retrobulbar anesthesia used for their initial PKP.

RESULTS

The mean intraoperative VPS score was 0.51 +/- 0.32 (range 0-1.33), and the mean postoperative VPS score was 0.47 +/- 0.50 (range 0-1.67). There were no serious intraoperative or postoperative complications. All patients reported high mean satisfaction score of 4.67 +/- 0.49 (range 4-5). The mean satisfaction score reported by the surgeon was 4.47 +/- 0.63 (range 3-5). All patients but 1 (93.3%) preferred combined topical over retrobulbar anesthesia, which they had in their previous surgery.

CONCLUSIONS

We found combined topical and intracameral anesthesia to be safe and effective in our selected group of patients undergoing repeat PKP, and it may provide a satisfactory alternative anesthetic modality for patients in whom general, retrobulbar, or peribulbar anesthesia may be contraindicated.

Central retinal artery occlusion after peribulbar anesthesia

We describe the development of central retinal artery occlusion (CRAO) in 2 patients after peribulbar (periconal) anesthesia during uneventful phacoemulsification. Although peribulbar anesthesia avoids direct optic-nerve injury, indirect injury presenting as CRAO may occur from vasospasm in response to the injection.

Complications of ophthalmologic nerve blocks: a review

Complications of ophthalmologic nerve blocks are rare, but they can have serious life- and sight-threatening consequences. Knowledge of the potential complications is essential for the anesthesiologist who performs ophthalmologic nerve blocks. However, most anesthesiologists are unfamiliar with these complications because the majority have been reported in the ophthalmology literature. We review the complications that may occur during the placement of ophthalmologic blocks and their appropriate prompt treatment.

Transient central retinal artery occlusion after posterior sub-Tenon's anesthesia

Two cases of transient central retinal artery occlusion were observed preoperatively after uneventful sub-Tenon's infusion of local anesthetic for cataract surgery and intraocular lens implantation. In these eyes, the retinal circulation reperfused spontaneously before surgery and there were no visual sequelae. A third case was observed in an eye after strabismus surgery with sub-Tenon's anesthesia. The patient was left with profound visual loss in this eye. The cause of this complication is unknown, but possible factors include mechanical pressure from the bolus of the anesthetic solution or localized vasoconstriction from the anesthetic, producing a decrease in ocular blood flow. Suggestions to avoid this problem include not inserting the cannula too posteriorly, not injecting forcibly against resistance, and using the minimum volume of anesthetic possible.

Patient-controlled analgesia and sedation with fentanyl in phacoemulsification under topical anesthesia

PURPOSE

To investigate the effects of intravenous (IV) patient-controlled sedation/analgesia with fentanyl during phacoemulsification surgery under topical anesthesia.

SETTING

Adnan Menderes University Medical School, Departments of Ophthalmology and Anesthesiology and Reanimation, Aydin, Turkey.

METHODS

In this double-blind randomized study, 68 patients were randomly allocated to 2 groups. In the fentanyl group comprising 34 patients, fentanyl was administered by patient-controlled analgesia (PCA) equipment in 5 microg bolus doses with a lockout period of 5 minutes after an IV loading dose of 0.7 microg/kg in 2 mL balanced salt solution. In the control group comprising 34 patients, a balanced salt solution was given without an analgesic drug by PCA equipment. Verbal pain scale (VPS) and sedation scores were recorded preoperatively and 5, 10, 15, 20, and 30 minutes after the start of surgery. Patient comfort and surgeon satisfaction were assessed postoperatively.

RESULTS

The sedation score was higher in the fentanyl group than in the control group at 5 and 10 minutes (P =.006 and P =.012, respectively). The VPS scores were higher in the control group than in the fentanyl group at 15 and 20 minutes (P =.02 and P =.016, respectively). Patients pressed the button for additional analgesia 2.6 times +/- 3.9 (SD) in the control group and 0.9 +/- 1.6 times in the fentanyl group (P =.025). Patient and surgeon satisfaction were higher in the fentanyl group than the control group (P =.023 and P =.018, respectively).

CONCLUSIONS

The results of this study suggest that IV PCA with fentanyl has supplemental effects on analgesia and sedation during cataract surgery under topical anesthesia and increases patient comfort and surgeon satisfaction.

Complications of peripheral blockade

The wide variety of peripheral blocks makes for a difficult endeavor in trying to grasp their many potential complications. However, the common features of these complications makes it possible to use the construct presented here, in combination with one's knowledge of anatomy, to be able anticipate many, if not most, of the complications of any particular peripheral regional anesthetic.

Neuro-ophthalmologic complications of cataract surgery

Neuro-ophthalmologic complications from cataract surgery are uncommon and include central nervous system toxicity, binocular diplopia, traumatic optic neuropathy and ischemic optic neuropathy. Retrobulbar blocks may be accidentally injected into the subarachnoid space with diffusion to the brainstem. This leads to cardiovascular, respiratory, and mental status compromise. Most patients have complete recovery with adequate support. Post-operative, binocular diplopia may occur secondary to anisometropia or previously unrecognized misalignment. Periocular injection may cause paresis or fibrosis of extraocular muscles. Anterior or posterior ischemic optic neuropathy can occur in the first 6 weeks after cataract surgery with or without periocular injection. The risk to the other eye is high with subsequent contralateral cataract extraction. Post-operative vision loss associated with direct traumatic needle injury is recognized immediately. Therefore, an orbital MRI may be warranted for a patient with an optic neuropathy in the first 24 hours after cataract surgery using periocular anesthesia. If evidence of needle injury is present on neuroimaging, a trial of steroids should be considered.

A comparison of topical and retrobulbar anesthesia for trabeculectomy

PURPOSE

To compare the safety and efficacy of topical versus retrobulbar anesthesia for primary trabeculectomy

METHODS

A prospective study of 36 consecutive patients undergoing trabeculectomy who were randomized to receive topical (n = 18) or retrobulbar (n = 18) anesthesia. Operating conditions, patient comfort, and surgical outcome were evaluated.

SETTINGS

Tertiary-care university hospital ambulatory surgical center.

RESULTS

There were no differences in operating conditions (P = 0.14), pain during (P = 0.54) or after (P = 0.76) surgery, or supplemental anesthesia required (P = 0.34) between the two groups. Very few patients in either group were bothered by touch sensation, tissue manipulation, or the microscope light. Chemosis, subconjunctival hemorrhage and eyelid hemorrhage were seen exclusively in the retrobulbar group (P <0.03), and were all attributable to the injection. Inadvertent eye movement was present more frequently in the topical group (P = 0.01), although this did not pose a problem to the surgeon. No surgical complications were encountered in either group.

CONCLUSION

Topical anesthesia is a safe and effective alternative to retrobulbar anesthesia for primary trabeculectomy.

Topical anesthesia in phacotrabeculectomy

PURPOSE

To study the safety and efficacy of topical anesthesia alone, without systemic sedation, in phacotrabeculectomy for cataract and primary open-angle glaucoma.

METHODS

In this prospective study, topical anesthesia with 2% lidocaine hydrochloride jelly without systemic sedation was used for combined phacoemulsification, posterior chamber intraocular lens implantation, and trabeculectomy in consecutive patients with primary open-angle glaucoma and concurrent cataract at the United Christian Hospital, Kowloon, Hong Kong, from September 2000 to May 2001. Visual analog pain score and change in vital signs were used to assess the intraoperative pain experience. Other outcome measures included postoperative visual acuity and intraocular pressure at 3 months.

RESULTS

Twenty-two eyes of 22 consecutive patients were included in the study. The mean intraoperative pain score was 0.9 (range, 0-3). Three patients reported discomfort intraoperatively. No injection of supplementary anesthetic was required in any of the eyes. None of the patients had significant increase of pulse rate or blood pressure during the whole surgical procedure. Six patients required oral analgesic for postoperative discomfort. The mean preoperative medically treated IOP was 20.3 +/- 5.9 mm Hg and the mean postoperative IOP at 3 months was 14.4 +/- 4.7 mm Hg. All except two patients had improved visual acuity. There was no serious intraoperative or postoperative complication.

CONCLUSION

Topical 2% lidocaine hydrochloride jelly without systemic sedation may be a safe and effective anesthetic method in phacotrabeculectomy for patients with primary open-angle glaucoma with coexisting cataract.

Topical versus retrobulbar anesthesia for combined phacotrabeculectomy: prospective randomized study

PURPOSE

To compare the safety and efficacy of topical and retrobulbar anesthesia for combined phacotrabeculectomy.

SETTING

Tertiary-care university hospital ambulatory surgical center.

METHODS

In this prospective study, 40 consecutive patients having combined phacotrabeculectomy were randomized to receive topical (n = 20) or retrobulbar (n = 20) anesthesia. Operating conditions, patient comfort, and surgical outcome were evaluated.

RESULTS

There was no significant between-group difference in operating conditions (P =.56), pain during (P =.41) or after (P =.23) surgery, or supplemental anesthesia required (P =.49). Few patients in either group were bothered by tissue manipulation or the microscope light, although more patients in the topical group were slightly bothered by touch sensation (P =.05). Chemosis, subconjunctival hemorrhage, and eyelid hematoma were seen almost exclusively in the retrobulbar group (P <.05). Inadvertent eye movement was present more frequently in the topical group (P =.04), although this did not pose a problem to the surgeon.

CONCLUSION

Topical anesthesia is a safe and effective alternative to retrobulbar anesthesia for combined phacotrabeculectomy.

Effect of sub-Tenon's and peribulbar anesthesia on intraocular pressure and ocular pulse amplitude

PURPOSE

To compare the effect of peribulbar and sub-Tenon's anesthesia on intraocular pressure (IOP) and ocular pulse amplitude (OPA) in the injected eye and the fellow noninjected (control) eye.

SETTING

Tel Aviv Medical Center, Tel Aviv, Israel.

METHODS

This prospective study measured IOP and OPA at baseline and 1 and 10 minutes after administration of lidocaine anesthesia in 40 consecutive adult patients having elective cataract surgery.

RESULTS

The IOP remained stable throughout the study with both modes of anesthesia. One minute after injection of the anesthetic agent, the OPA was significantly decreased in the injected eyes in both the sub-Tenon's (24%; P < .05) and peribulbar (25%; P < .05) groups. The decrease in the OPA in the sub-Tenon's group (14%; P < .05) was detectable after 10 minutes in the control eyes. In the peribulbar anesthesia group, the OPA in the control eyes increased significantly (9%; P < .05) 1 minute after injection of the anesthetic agent, returning to preinjection levels 10 minutes after the injection.

CONCLUSIONS

The OPA in the eyes in which lidocaine was injected decreased significantly in both the sub-Tenon's and peribulbar groups. These findings have implications for the management of patients whose ocular circulation may be compromised.

Cataract surgery under topical anesthesia in patients with coexisting glaucoma

PURPOSE

To evaluate and compare levels of patient discomfort and complications during phacoemulsification with implantation of a foldable intraocular lens (IOL) under topical lidocaine hydrochloride in patients with and without various forms of chronic open-angle and chronic angle-closure glaucoma.

SETTING

Two university eye centers in Germany.

METHODS

This prospective nonrandomized comparative study comprised 176 eyes of 176 patients with various forms of chronic open-angle glaucoma and chronic angle-closure glaucoma. Eyes with cataract and without a glaucoma diagnosis or history of intraocular surgery served as a control group (n = 212). All patients received a minimum of 5 doses (2 drops per dose) of topical lidocaine hydrochloride 2% before standard temporal clear corneal phacoemulsification and foldable IOL implantation. No intracameral anesthetic injection was given, and no systemic sedatives were used. The main outcome measures were the number of complications and adverse events.

RESULTS

The intraoperative complication rate in all patients (n = 388) was capsule tear, 1.3%; zonule tear, 1.8%; vitreous loss, 1.0%; iris prolapse, 0.8%. No statistically significant differences in intraoperative or early postoperative complications were found between the glaucoma and control groups. The mean pain scores of patients were 0.38 +/- 1.1 (SD) in the glaucoma group and 0.36 +/- 0.8 in the control group (P =.21) Patient preference for cataract surgery under topical anesthesia was similar in both groups.

CONCLUSIONS

Surgery-related complications and patient discomfort were similar in patients with and without glaucoma who had phacoemulsification and IOL implantation under topical anesthesia. These results indicate that topical anesthesia is safe for routine phacoemulsification with foldable IOL implantation in patients with glaucoma and does not compromise patient comfort.