Effect of hyaluronidase on ocular motility in sub-Tenon's anesthesia: randomized controlled trial

PURPOSE: To assess the effect of hyaluronidase additive on the onset and degree of ocular akinesia in sub-Tenon's anesthesia for cataract surgery. SETTING: Routine cataract operating list. METHOD: This double-blind randomized controlled study comprised 100 patients who had phacoemulsification cataract surgery. Patients were randomized to 1 of 2 groups. For sub-Tenon's anesthesia, Group A received 5 mL lignocaine 2% with sodium hyaluronidase 150 IU/mL and Group B, 5 mL plain lignocaine 2%. Akinesia was assessed by scoring movement in the 6 positions of gaze. Scores ranged from 0 (complete akinesia) to 3 (no akinesia). Movements were measured at 30 seconds and 1, 3, 5, and 10 minutes. Changes in motility scores were compared by the Mann-Whitney U test. RESULTS: There was no significant difference in akinesia between the 2 groups 30 seconds after the injection (P =.224); however, at 1 and 3 minutes, Group A achieved significantly better akinesia than Group B (P =.003 and P =.023, respectively). The median score after 3 minutes was 3.5 (interquartile range 0 to 7.5) in Group A and 7.0 (interquartile range 2.5 to 10.0) in Group B. There was no significant difference between the groups at 5 and 10 minutes (P =.225 and P =.831, respectively). CONCLUSIONS: The addition of hyaluronidase in sub-Tenon's anesthesia significantly improved the rapidity of the onset of akinesia. This benefit disappeared over time; after 5 minutes the akinesia observed in the group receiving hyaluronidase was similar to that in the group receiving lignocaine alone. Thus, there appears to be no benefit to adding hyaluronidase to the anesthetic solution in terms of final ocular akinesia.     

Sub-Tenon's local anaesthesia: the effect of hyaluronidase

AIMS: A prospective, randomised, double blind study was used to investigate the effect of hyaluronidase on the quality of block achieved with sub-Tenon's local anaesthesia. METHODS: 150 patients scheduled for elective cataract surgery were randomly allocated to either sub-Tenon's block with 3 ml lignocaine 2%/adrenaline 1:200 000 alone or with the addition of 30 IU/ml of hyaluronidase. The blocks were assessed for degree of akinesia and reduction of eyelid movement, and also post-injection and postoperative pain scores. RESULTS: Akinesia and reduction of eyelid movement measured 10 minutes after injection were significantly better in the group with hyaluronidase added to the anaesthetic solution. Postoperative pain scores were not significantly different between the two groups but the post-injection pain score was greater (marginally significant) in the group with hyaluronidase added. CONCLUSION: The addition of hyaluronidase significantly improves the quality of the motor blockade achieved with sub-Tenon's local anaesthesia, but has no effect on the sensory blockade.     

Sub-Tenon's block with an ultrashort cannula

PURPOSE: To evaluate the effectiveness and safety of an orbital block using an ultrashort, wide-bore blunt metal cannula to inject local anesthetic agents into the anterior sub-Tenon's space. SETTING: Department of Ophthalmology, North Riding Infirmary, Middlesbrough, United Kingdom. METHODS: Fifty-nine consecutive patients having routine phacoemulsification with intraocular lens implantation were studied. Five milliliters of lidocaine 2% with adrenaline 1:200000 and hyaluronidase 150 units was injected into the anterior sub-Tenon's space in the inferonasal quadrant via a 16-gauge, short (0.6 cm), blunt metal cannula. Horizontal and vertical movements were assessed before injection and 2, 4, and 6 minutes after injection (also at 8 and 10 minutes if akinesia was inadequate). The movements were scored from 0 (no movement) to 3 (full movement). Incyclotorsion and lid movements were assessed at the same intervals. In the first 15 patients, B-scan ultrasonography was performed before, during, and 2 minutes after the injection. If the aggregate akinesia score was higher than 4 at 6 minutes, a supplementary injection was given. Pain during the injection and surgery was assessed using a 10-point verbal rating score. The incidence, severity, and quadrant of chemosis and conjunctival hemorrhage were noted. RESULTS: Forty-eight patients (81.35%) had an aggregate akinesia score lower than 4 at 2 minutes and 58 (98.30%) at 4 minutes. One patient had an akinesia score higher than 4 at 6 minutes and required supplementary injection. Incyclotorsion was present in 42 patients (72.88%) at 2 minutes and in 19 (32.20%) at 4 minutes. Lid opening (levator function) was present in 33 patients (55.93%) at 2 minutes and in 19 (32.20%) at 4 minutes. Lid closure (orbicularis function) was present in 34 patients (57.62%) at 2 minutes and in 18 (30.50%) at 4 minutes. One patient required a supplementary injection at 10 minutes. Ultrasonography showed the injection caused rapid opening of sub-Tenon's space, with fluid spreading around the optic nerve. No pain on injection occurred in 67.79% of patients; 17 (28.81%) had a verbal rating score of 1, 1 (1.69%) had a score of 3, and 1 had a score of 5. No patient reported pain during surgery. A minor degree of chemosis and conjunctival hemorrhage occurred in 43 patients and 37 patients, respectively. Moderate chemosis occurred in 15 cases and severe chemosis in 1 case. CONCLUSIONS: Effective and predictable ocular anesthesia can be achieved using a blunt, ultrashort cannula for sub-Tenon's block. The technique greatly reduces the risks for globe perforation, muscle damage, and other serious complications.     

Addition of hyaluronidase to lignocaine with adrenaline for retrobulbar anaesthesia in the surgery of senile cataract.

A double-blind trial demonstrates the effectiveness of adding hyaluronidase to lignocaine with adrenaline in producing ocular akinesia and anaesthesia in retrobulbar nerve blocks. 92% of the blocks in which hyaluronidase was used for intracapsular cataract surgery were judged successful compared with 56% of those without added hyaluronidase (p less than 0.01).     

Re-evaluation of hyaluronidase in peribulbar anaesthesia.

AIMS/BACKGROUND: Hyaluronidase can augment the actions of local anaesthetics in peribulbar anaesthesia. However, evidence suggests satisfactory anaesthesia can be achieved using mixtures without hyaluronidase. A randomised double blind study was conducted on 50 patients, undergoing peribulbar anaesthesia, to validate this observation. METHODS: Patients received a standard mixture of local anaesthetic (0.5% bupivacaine and 2% lignocaine in a 1:1 ratio) with or without hyaluronidase (25 IU/ml of mixture), pH values 5.16 and 5.24 respectively. Time taken to establish satisfactory anaesthesia to allow surgery was noted. RESULTS: The onset time to globe akinesia in the control group ranged from 2 to 15 minutes (mean 5.64 and median 4 minutes) and in the hyaluronidase group from 2 to 12 minutes (mean 4.64 and median 4 minutes). The volume of local anaesthetic injected to achieve satisfactory anaesthesia ranged from 8 to 16 ml (mean 10.96, SD 1.95) in the control group and 10 to 18 ml (mean 11.64, SD 2.8) in the hyaluronidase group. A Mann-Whitney test to compare onset times to globe akinesia between groups gave a p value = 0.6 and 95% confidence interval (-1 to 2 minutes). CONCLUSION: Addition of 25 IU/ml of hyaluronidase to a standard pH unadjusted local anaesthetic mixture does not significantly reduce the time to the onset of satisfactory globe akinesia.     

A comparison of three sub-Tenon's cannulae

PURPOSE: To compare the quality of anaesthesia and complication rates between three sub-Tenon cannula of increasing length (anterior Greenbaum, mid Kumar-Dodds, and posterior Steven's sub-Tenon's cannulae). METHODS: A total of 150 patients undergoing cataract extraction were randomised to receive a sub-Tenon injection of 5 ml of 2% lidocaine with hyaluronidase with one of the three cannulae. The development of akinesia was assessed every 2 min over a 6-min period. Complications were also recorded. RESULTS: There was no difference in the onset of akinesia, with 46, 50, and 46 patients achieving adequate akinesia within 6 min for the anterior, mid, and posterior groups respectively (P>0.05). There was an increase in retained lid opening with anterior compared to mid and posterior cannulae (P=0.0001). There was significantly less retained lid closure with the posterior compared to the mid or anterior cannulae (P<00001). The mean (range, SD) scores for pain during injection were 0.4 (0-5, 0.83), 1.2 (0-9, 1.96), and 1.1 (0-6, 1.19) for the anterior, mid, and posterior groups, respectively. These were not significantly different between the anterior and mid groups, or the mid and posterior groups (P>0.05), but there was significantly more pain on injection with the posterior compared to the anterior groups (P<0.01). All patients scored intraoperative pain as zero. There was significantly more chemosis in the anterior group (76%) compared to the mid (20%) and posterior (32%) groups (P<0.0001). There were significantly (P=0.0004) more conjunctival haemorrhages in the anterior group (56%) than the mid (20%) or posterior (20%) groups. CONCLUSIONS: We have shown that all three cannulae provide high-quality anaesthesia with minor differences in retained muscle activity, chemosis, and haemorrhage rates.     

Techniques of facial nerve block.

The efficacy of different techniques of facial nerve block for cataract surgery was investigated. Forty four patients underwent either modified O'Brien, Atkinson, van Lint, or lid blocks. Intentional muscle activity of the orbicularis oculi muscle was recorded and the area under the EMG curve calculated for quantitative comparison of muscle activity between the groups before and after injection of lignocaine with the vasoconstrictor naphazoline nitrate. In addition, the force of lid closure was measured and lid motility determined on a subjective score scale. Whereas the modified O'Brien and lid blocks nearly abolished the muscle activity recorded in the EMG (p < 0.003), the Atkinson and van Lint blocks did not significantly affect these variables. The O'Brien and lid blocks decreased the force of lid closure and lid movements far more effectively than the Atkinson and van Lint blocks (p < 0.0001). The topographic distribution of a mixture of metrizamide and lignocaine solutions was evaluated radiographically in eight additional patients, to assess potential causes for differences in the efficacy of the block techniques. The radiological results showed involvement of the region of the facial nerve trunk and its temporal and cervical divisions by the modified O'Brien block. The lid block, on the other hand, affected terminal branches of the facial nerve's temporal division. In this study, complete lid akinesia was achieved by both the modified O'Brien block and the lid block. However, because the modified O'Brien block involves the risk of neural injury to the facial nerve or its main divisions, the lid block is recommended as the most effective and safe method to achieve akinesia of the orbicularis oculi muscle.     

The efficacy and safety of 0.75% levobupivacaine vs 0.75% bupivacaine for peribulbar anaesthesia

BACKGROUND: Levobupivacaine, the S(-)-enantiomer of racemic bupivacaine, is associated with a similar efficacy but a reduced potential for cardiovascular and central nervous system toxicity than racemic bupivacaine. Thus, this prospective, randomised, double-masked study was undertaken to assess the efficacy and safety of 0.75% levobupivacaine vs 0.75% bupivacaine, each with hyaluronidase, for peribulbar anaesthesia. METHODS: A total of 60 patients undergoing elective anterior segment surgery were randomly allocated to receive either agent by a single, inferotemporal peribulbar injection technique, supplemented with a medial canthus injection if necessary. Ocular akinesia and orbicularis oculi function were assessed by scoring systems at 2 min intervals until satisfactory akinesia was achieved, and movements were reassessed on the day after surgery to confirm regression of the block. RESULTS: The time taken to reach a state of satisfactory anaesthesia and akinesia was deemed to be the primary measure of efficacy. Both agents achieved this in a similar median time of 2 min after receiving 5 ml of the injectate, and the treatment difference was not statistically significant (P=0.24). Blood samples from the first 20 patients were taken at intervals up to 4 h. These were analysed for plasma levels and confirmed similar plasma concentration vs time profiles for the two agents. Seven patients in each group (23%) complained of pain on injection but the technique was generally well tolerated. Two patients in the levobupivacaine group experienced serious adverse events, but neither was considered related to the study medication. The most common minor post-operative adverse event was prolongation of the local anaesthetic block, which was reported by nine patients (four in the levobupivacaine group and five in the bupivacaine group). CONCLUSIONS: Levobupivacaine and bupivacaine are equally successful in achieving clinically satisfactory peribulbar anaesthesia with few adverse effects.     

Does the addition of hyaluronidase improve the quality of peribulbar anesthesia in cataract surgery? – A randomized double blinded study

Purpose

To determine the necessity of hyaluronidase as an anesthetic adjuvant for peribulbar anesthesia during cataract surgery and to assess differences in anesthetic outcomes in the absence of hyaluronidase.

Effect of volume used in sub-Tenon's anaesthesia on efficacy and intraocular pressure: a randomized clinical trial of 3 mL versus 5 mL

PURPOSE: To compare the effect of volume used in sub-Tenon's anaesthesia on efficacy and intraocular pressure (IOP). METHODS: A prospective, randomised clinical trial was conducted on 52 eyes of 52 consecutive patients undergoing sub-Tenon's anaesthetic for cataract surgery. Eyes were randomly assigned to either 3 mL or 5 mL volume of anaesthetic solution (0.5% bupivacaine/2% lidocaine in a 50:50 mixture). The main outcome measures were akinesia 5 min post-administration of anaesthetic, changes in IOP immediately after and 5 min after anaesthetic administration, and patient pain perception during procedure. RESULTS: The level of kinesia was greater in the 3 mL group (n = 25) compared to the 5 mL group (n = 27) (P = 0.001, Mann-;Whitney U-test). There was no significant difference in pain perception between the two groups (P = 0.464, student t-test). Although there was great variation in IOP changes following sub-Tenon's anaesthetic, there was a trend for a larger rise in mean IOP immediately after anaesthetic administration in the 5 mL group (mean +/- SD +5.6 +/- 4.2 mmHg) compared to the 3 mL group (+4.3 +/- 3.8 mmHg), but this did not reach statistical significance (P = 0.25, student t-test). CONCLUSIONS: A 5 mL volume of anaesthetic provides akinesia superior to a 3 mL volume in sub-Tenon's anaesthesia for cataract surgery.     

The effect of hyaluronidase on ultrasound-measured dispersal of local anaesthetic following sub-Tenon injection

PurposeTo determine by B-scan ultrasonography if the addition of hyaluronidase affects the dispersal of anaesthetic fluid after sub-Tenon's injection.DesignSingle-centre prospective randomised double-blind study.Materials and methodsWe performed a trial in 19 patients who were randomised to receive 5 ml of lidocaine 2% alone, or with hyaluronidase 15 IU/ml. A pre-anaesthetic B-scan ultrasound was performed followed by a standard infero-nasal sub-Tenon's injection. Further B-scan ultrasound studies were performed at 1, 3, and 5 min recording depth of local anaesthetic fluid. Data was analysed with Fisher's exact test and Student's t-test where appropriate. Results were considered significant when P<0.05.ResultsThe maximum depth of local anaesthetic was significantly less in the hyaluronidase group than the control group at 3 and 5 min (0.79 vs1.65 mm, P-value 0.01 and 0.43 vs1.52 mm, P-value 0.002 respectively). There were no statistically significant differences in the akinesia, pain and surgical satisfaction scores between the two groups.ConclusionsThe addition of hyaluronidase significantly augments the dispersal of local anaesthetic fluid, as measured by B-scan ultrasonography.Eye (2008) 22, 1065-1068; doi:10.1038/sj.eye.6702860; published online 25 May 2007.     

Sub-Tenon's anaesthesia: an efficient and safe technique

AIM—To evaluate sub-Tenon' s anaesthesia as an alternative to peribulbar anaesthesia.
METHODS—109 consecutive patients listed for various eye operations (including cataract, trabeculectomy, and vitrectomy) under peribulbar anaesthesia were operated on under sub-Tenon's anaesthesia instead. After topical anaesthesia a buttonhole was fashioned through the conjunctiva and Tenon's capsule 10 mm posterior to the limbus. 1.5 ml of lignocaine 2% was then delivered to the posterior sub-Tenon's space using a blunt cannula. The surgical procedure was performed immediately after the completion of the anaesthetic procedure. Chemosis, conjunctival haemorrhage, degree of akinesia, and pain scoring were analysed.
RESULTS—There were no anaesthesia related complications. The administration of the block was painless for 99.1% of the patients. In all, 97.3% reported no pain during surgery. There was no akinesia when assessed just after the completion of the block and akinesia was limited when assessed after surgery. Chemosis and conjunctival haemorrhage were frequent but caused no intraoperative problems.
CONCLUSION—Sub-Tenon's anaesthesia is an efficient and safe anaesthetic technique. It is a good alternative to peribulbar anaesthesia.

     

Intraoperative eye position after sub-Tenon's anesthesia for cataract surgery

BACKGROUND: To evaluate the incidence and extent of ocular deviation associated with sub-Tenon's anesthesia. METHODS: Seventy-five consecutive patients undergoing routine phacoemulsification with sub-Tenon's anesthesia at the Eye Unit, Royal Gwent Hospital, were prospectively enrolled in this observational case series. The exclusion criteria were patients taking warfarin, or patients with preexisting ocular motility disorders, allergy to local anesthetics, or previous surgery for squint or retinal detachment. Eleven patients were subsequently excluded from the study group as they required additional anesthesia blocks before measurements were taken for ocular deviation. We injected 5 mL of a local anesthetic mixture of 2% lignocaine and 7.5 mg/mL levobupivacaine in the sub-Tenon's space in the inferonasal quadrant. Ocular deviation was assessed objectively by means of the Krimsky test. Forced duction tests were performed before and after anesthesia. RESULTS: Hyperdeviation was documented in 49 (77%) eyes, exodeviation in 62 (97%), and hypodeviation in 6 (9.4%). No esodeviations were documented. Only 2 patients were orthophoric after anesthesia. Mean vertical deviation was 4.4 prism dioptres (PD) (SD 4.7 PD, 95% CI 3.2-5.5 PD, range 0-14 PD). Mean horizontal deviation was 19.5 (SD 9.6, 95% CI 17-22, range 0-50) PD. Forced duction test revealed no mechanical restriction before or after anesthesia. INTERPRETATION: This study suggests that there is an appreciable ocular deviation with sub-Tenon's anesthesia. Intraoperative ocular deviation may make certain procedures more difficult; therefore, we recommend a low threshold for an additional corrective block administered before surgery to rectify the deviation.     

Sodium bicarbonate--an alternative to hyaluronidase in ocular anaesthesia for cataract surgery

PURPOSE: To evaluate and compare the safety, efficacy and cost-effectiveness of 7.5% sodium bicarbonate buffered lidocaine (pH 7.2) with hyaluronidase mixed lidocaine (pH 4.6) for local anaesthesia in cataract surgery. METHODS: This prospective study comprised two parts. Part I: We evaluated the ocular and systematic anaesthetic safety and efficacy of 7.5% sodium bicarbonate buffered lidocaine on 112 consecutive patients undergoing cataract extraction with intraocular lens (IOL) implantation. At 12-week postoperative follow up final visual acuity and detailed fundus examination was done. Part II: It was conducted as a double blind, randomized comparative clinical trial involving 120 patients undergoing cataract surgery under retrobulbar anaesthesia. Patients were randomly assigned to one of the two groups: 60 eyes received 2 ml of 2% lidocaine with 1:200,000 epinephrine and 1 ml of 7.5% sodium bicarbonate, (0.299 mmol/ml); the remaining 60 eyes received 2 ml of 2% lidocaine with 1:200,000 epinephrine and 450 units of hyaluronidase (15 U/ml). In the event of incomplete akinesia, retrobulbar blocks were supplemented at 10 minutes. Onset and duration of anaesthesia and akinesia were assessed and compared in both groups. RESULTS: The pH-adjusted lidocaine group did not show any demonstrable variation in blood pressure (BP) or other systemic reaction. No anaesthesia-related adverse ocular effects were observed either during or after surgery. Thirty-one eyes (51.6%) achieved complete anaesthesia and akinesia within 5 minutes compared to 13 eyes (21.6%) in the hyaluronidase group. However, the overall mean onset time of anaesthesia and akinesia, repeat block rate and the duration of the anaesthesia were comparable in both the groups--p: 0.14). Twelve weeks postoperatively 88.39% of patients showed a best corrected visual acuity of 6/18 or better (73.21%-6/12 or better). CONCLUSION: In this study, sodium bicarbonate buffered 2% lidocaine was found to be a safe and effective local anaesthetic, with reduced time of onset, and improved quality of both anaesthesia and akinesia. Sodium bicarbonate (7.5%) may be used as an alternative to hyaluronidase in ocular anaesthesia. It is readily available and is cost effective.     

Isolated levator myositis

A 54-year-old woman presented with a 1-day history of ptosis of the left upper lid. On examination, the patient exhibited a moderate ptosis, poor levator function, lid lag on down-gaze, and no limitation of ocular motility. A computed tomography (CT) scan with contrast demonstrated enhancement of the levator muscle and levator aponeurosis on the involved side. Treatment consisted of systemic steroid administration and led to complete resolution of the ptosis in 2 weeks. The combined clinical and CT scan findings give a characteristic pattern of an isolated levator myositis.     

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.     

Topical anaesthesia with oxybuprocaine versus sub-Tenon's infiltration with 2% lignocaine for small incision cataract surgery

AIMS—To determine whether topical anaesthesia in small incision self-sealing phacoemulsification cataract surgery provides comparable anaesthesia to sub-Tenon's infiltration.
METHODS—Thirty five patients undergoing small incision self-sealing phacoemulsification cataract surgery were allocated randomly to receive topical anaesthesia with 0.4% oxybuprocaine or sub-Tenon's infiltration with 2% lignocaine. Pain experienced during the operation was assessed by asking the patient to score on a visual analogue graphic pain score chart.
RESULTS—The median pain score for the topical group (3) was significantly higher than that of the sub-Tenon's group (0) (p = 0.004).
CONCLUSION—Sub-Tenon's infiltration is superior to topical anaesthesia in ensuring patient comfort during small incision scleral tunnel self-sealing phacoemulsification cataract surgery.

     

Peribulbar anaesthesia for penetrating keratoplasty. A case series

PURPOSE: To prospectively analyse the efficacy and safety of peribulbar anaesthesia for penetrating keratoplasty through a noncomparative, consecutive series. METHODS: One hundred twenty-four (91.1%) of 136 patients undergoing penetrating keratoplasty (PK) from January 1997 to December 2001, were administered peribulbar anaesthesia. The anaesthetic mixture consisted 5 ml of lignocaine, bupivacaine, and hyaluronidase (to avoid evaluation bias) in the peribulbar space. A repeat injection of 3 ml was used if the primary injection was inadequate. Digital ocular compression was done for 10-15 minutes after the first injection. Each patient was analysed for degree of akinesia, subjective patient comfort, analgesia, subjective surgeon comfort, and types of surgical conditions. RESULTS: The age ranged from 19 to 86 years. Forty-nine of 124 patients (39.5%) received PK only and remaining 75 patients (60.5%) received additional procedures. A single injection was sufficient to achieve adequate akinesia (grade II and III) in 114 (92%) patients and 120 (97%) of patients were satisfied (graded pain as < or = grade II). During surgery, 6 (5%) phakic eyes developed episodes of positive intraocular pressure and 5 eyes (4%) developed chemosis. There were no other local or systemic adverse events. The surgeon level comfort was (grade II or more) 98% (122 of 124). CONCLUSION: One-point, low volume, peribulbar anaesthesia for penetrating keratoplasty is safe and efficacions.