Cluster of diplopia cases after periocular anesthesia without hyaluronidase

Strabismus patterns after cataract surgery in adults

New-onset binocular diplopia after cataract surgery in adults is a rare but significant complication. The aim of this study was to analyze causes, risk factors, and treatment outcomes. Forty consecutive patients with new-onset binocular diplopia after uncomplicated cataract surgery were enrolled in this retrospective study at a tertiary medical center. We evaluated risk factors including type of anesthesia, preoperative presence of strabismus, and others regarding their effect on the development of diplopia after cataract surgery. We further analyzed ocular alignment and motility at presentation and during the clinical course. The majority of the patients with new-onset diplopia presented after cataract surgery on the left eye (28 of 40). Vertical strabismus occurred in 37 of 40 patients, and regional (peri- or retrobulbar) anesthesia was the main risk factor for postoperative diplopia (present in 37 of 40). There were four distinct ocular dysmotility patterns in patients with vertical strabismus: deficient elevation with (type 1a) or without over-depression (type 1b), deficient depression (type 2), or normal motility (type 3). After surgery of the right eye, most patients (6 of 9) showed type 2. After cataract surgery on the left eye, type 1a was most common (20 of 24). Three patients had horizontal strabismus due to a decompensated heterophoria or convergence insufficiency. In total, 17 patients required strabismus surgery (mean 1.3 operations, range 1-3). Regional anesthesia was the main risk factor for new-onset diplopia after cataract surgery in adults. Distinct strabismus patterns were observed for left and right eyes.d.

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Prevalence of Diplopia Related to Cataract Surgery among Cases of Diplopia

Purpose

To evaluate the prevalence of diplopia in Greece after cataract surgery among diplopia cases.

Methods

The authors retrospectively reviewed the medical records of 571 patients with diplopia over an 8-year period in order to evaluate the prevalence of diplopia related to cataract surgery. The surgical and anesthetic records were also reviewed. All patients had full orthoptic assessment including prisms with cover test in all gaze positions. The chi-square and cross-tabulation statistical tests were used for statistical analysis.

Results

Thirty-nine cases (6.8%) were having persistent diplopia related to cataract surgery. Type of anesthesia was peribulbar. Hyaluronidase was not used. Thirteen patients were men and 26 were women. Left eyes were involved in 22 cases (56.4%), right in 17 cases (43.6%). Mean age was 72.5 years. Patients were divided into four groups. Group 1 consisted of 29 patients related to surgical trauma due to anesthesia. Group 2 consisted of 7 patients related to pre-existing disorders. Group 3 consisted of 2 patients related to aniseikonia or anisometropia. Group 4 with 1 patient related to macular pathology. Vertical diplopia was mostly noted (28 cases). Twenty-nine patients were corrected with prisms, 9 needed strabismus surgery, and 1 needed both surgery and prisms.

Conclusions

Cataract surgery is not a common cause of persistent diplopia. However, this report highlights that prevalence of diplopia related to cataract is high among cases of diplopia in general, with diplopia being mostly vertical (p=0.001), affecting females (p=0.006), and being more common in left eyes, although results did not reach statistical significance (p=0.133).

Diplopia after Cataract Extraction

Diplopia after cataract extraction is an unexpected outcome for the patient and often a source of confusion for the physician, owing to its relative infrequency. This article reviews the pertinent literature on the subject. Mechanisms include anesthetic myotoxicity, surgical trauma, optical aberrations, cortical disorders in patients with congenital strabismus, and the unmasking of previously unnoticed ocular misalignment. As the population continues to age and cataract extraction is performed in increasing volume, familiarity with this uncommon but important outcome may help to clarify and effectively treat post-cataract-extraction diplopia.

Strabismus After Ocular Surgery

Many types of ocular surgery can cause diplopia, including eyelid, conjunctival, cataract, refractive, glaucoma, retinal, and orbital surgery. Mechanisms include direct injury to the extraocular muscles from surgery or anesthesia, scarring of the muscle complex and/or conjunctiva, alteration of the muscle pulley system, mass effects from implants, and muscle displacement. Diplopia can also result from a loss of fusion secondary to long-standing poor vision in one eye or from a decompensation of preexisting strabismus that was not recognized preoperatively. Treatment, which typically begins with prisms and is followed by surgery when necessary, can be challenging. In this review, the incidence, mechanisms, and treatments involved in diplopia after various ocular surgeries are discussed. [J Pediatr Ophthalmol Strabismus. 2017;54(5):272-281.].

Diplopia as the Complication of Cataract Surgery

The authors present systematic review of aetiology and treatment of diplopia related to cataract surgery. The problem is set in the modern perspective of changing cataract surgery. Actual incidence is discussed as well as various modalities of therapeutic options. The authors provide the guidance for the contemporary cataract surgeon, when to expect potential problem in ocular motility after cataract surgery.

Post-cataract surgery diplopia: aetiology, management and prevention

Diplopia is an infrequent but distressing adverse outcome after uncomplicated cataract surgery. Many factors may contribute to the occurrence of this problem, including prolonged sensory deprivation resulting in disruption of sensory fusion, paresis of one or more extraocular muscles, myotoxic effects of local anaesthesia, optical aberrations (for example, aniseikonia) and pre-existing disorders (for example, thyroid orbitopathy). The purpose of this review is to present the aetiology and clinical features of diplopia after cataract surgery and to discuss the possible modalities for the prevention and treatment of this frustrating complication.

Iatrogenic diplopia [corrected]

Diplopia is a very disturbing condition that has been reported as a complication of several surgical procedures. The following review aims to identify the ocular and nonocular surgical techniques more often associated with this undesirable result. Diplopia is reported as an adverse outcome of some neurosurgical procedures, dental procedures, endoscopic paranasal sinus surgery, and several ophthalmic procedures. The most common patterns and some recommendations in order to prevent and treat this frustrating outcome are also given.

Sub-Tenon's anesthesia: an update

Sub-Tenon’s block has become the most common technique of orbital regional anesthesia in many centers. It provides effective anesthesia to the orbit with a lower incidence of sight-threatening complications than sharp needle techniques. This article will discuss the relevant anatomy, finer points of sub-Tenon’s block technique, and the evidence supporting its safety.

Needle-based blocks for the 21st century ophthalmology

PURPOSE

This paper reviews history of the needle orbital blocks used in the earlier centuries and how they have evolved towards safer anaesthesia in the modern clinical practice.

METHODS

Material is derived from literature searches from major ophthalmic and anaesthetic journals on the use of orbital needle blocks over earlier centuries.

RESULTS

Needle-based anaesthetic techniques were described shortly after the invention of reliable medical needles. Atkinson popularized the classical retrobulbar block in a series of papers published in the early 20th century. This technique,which utilises a relatively long needle inserted towards the apex of the muscle cone behind the globe, has been criticized by some as unsuitable for modern 21st century ophthalmic surgery because of the extremely rare potential for serious complications. Satisfactory anaesthesia and akinesia can be obtained with short sharp or dull needles with slightly higher volumes of local anaesthetic agent placed in the farthest inferotemporal quadrant.

CONCLUSION

Aside from relative safety, modern needle blocks offer the advantage of lid akinesia without a need for a second injection for the seventh nerve that is often performed con-comitantly with retrobulbar block.

Diplopia and strabismus following ocular surgeries

Postoperative diplopia and strabismus may result from a variety of ocular surgical procedures. Common underlying mechanisms include sensory disturbance, scarring, direct extraocular muscle injury, myotoxicity from injections of local anesthesia or antibiotics, and malpositioning of extraocular muscles by implant materials. The most common patterns are vertical and horizontal motility disturbance. Treatment options include prisms, botulinum, occlusion, or surgery.

[Hyaluronidase: Here we go again]

OBJECTIVE

To summarize the benefits and lateral effects of hyaluronidase (H) use in ophthalmologic anaesthesia and to address its unavailability in current practice in France.

DATA SOURCES

The Medline data bank and the Cochrane database were consulted. The keywords employed separately or in combination were: H, regional anaesthesia, ophthalmologic surgery, local aneasthetics myotoxicity, diplopia.

STUDY SELECTION

Original articles since 1949 were selected. We also selected isolated clinical cases according to their relevance compared with the existing literature.

DATA SYNTHESIS

H is a "spreading factor" of animal origin used as an adjuvant in ophthalmic anaesthesia for more than half a century. It allows a moderate better block quality with a slightly quicker onset. It also limits the acute intraocular pressure increase secondary to periocular injection and seems to have a protective effect against local anaesthetics myotoxicity resulting in postoperative strabismus. However, during these last 50 years, numerous studies often ended in divergent results.

CONCLUSION

H seems to be a useful adjuvant in ophthalmologic anaesthesia in spite of his current unavailability in France. Recombinant H could be the solution in the near future.

Strabismus complications from local anesthetics

Strabismus developing after retrobulbar or peribulbar anesthesia for both anterior and posterior segment eye surgery may be due to myotoxicity to an extraocular muscle from the local anesthetic agent. Initial paresis often causes diplopia immediately after surgery, but later progressive segmental fibrosis occurs, and/or hypertrophy of the muscle, producing diplopia in the opposite direction from the direction of the initial diplopia. The inferior rectus muscle is most commonly affected. Usually a large recession on an adjustable suture of the involved muscle(s) yields good alignment. Using topical anesthesia or sub-Tenon's anesthesia can avoid this complication.

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

PURPOSE

To determine by B-scan ultrasonography if the addition of hyaluronidase affects the dispersal of anaesthetic fluid after sub-Tenon's injection.

DESIGN

Single-centre prospective randomised double-blind study.

MATERIALS AND METHODS

We 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.

RESULTS

The 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.

CONCLUSIONS

The addition of hyaluronidase significantly augments the dispersal of local anaesthetic fluid, as measured by B-scan ultrasonography.

Diplopia following cataract surgery: a review of 150 patients

AIM

To study the motility pattern, underlying mechanism, and management of patients who complained of double vision after cataract surgery.

METHODS

A retrospective case note analysis of 150 patients presenting with diplopia after cataract surgery to an orthoptic clinic over a 70-month period. Information was retrieved from orthoptic, ophthalmological, and operating room records.

RESULTS

A total of 3% of patients presenting to the orthoptic clinic had diplopia after cataract surgery. We grouped these according to the underlying mechanisms which were: (1) decompensating pre-existing strabismus (34%), (2) extraocular muscle restriction/paresis (25%), (3) refractive (8.5%), (4) concurrent onset of systemic disease (5%), (5) central fusion disruption (5%), and (6) monocular diplopia (2.5%). Twenty per cent of the patients could not be categorised with certainty. After infiltrational anaesthesia, extraocular muscle restriction/paresis was the commonest presentation, while decompensation of preexisting strabismus was commonest with topical anaesthesia.For the 150 patients seen, prisms were the commonest form of treatment prescribed (64%) either in isolation or in combination with other treatment, including surgery (19%). Convergence and divergence insufficiency/paresis patterns were also common. A changing motility pattern was noted in some patients who had early documentation, with increasing comitance over time (spread of comitance). Partial resolution made it difficult to clearly identify the underlying mechanism in patients with late documentation.

CONCLUSION

Double vision is a troublesome complication of otherwise successful cataract surgery. The use of topical anaesthesia does not abolish this surgical risk.

Prognostic factors for strabismus surgery after cataract surgery

PURPOSE

To evaluate the clinical features of strabismus that present after cataract surgery and determine the motor and sensory results after surgical correction of the strabismus.

SETTING

Department of Ophthalmology, the Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.

METHODS

Thirty-one patients who had strabismus surgery after cataract surgery between January 1996 and June 2004 were included in the study. The clinical features of strabismus and the factors contributing to successful strabismus surgery results were retrospectively analyzed. Sensory functional tests were performed postoperatively.

RESULTS

Fifteen patients (48.4%) had exotropia. The types of cataract included traumatic (35.5%), congenital (32.3%), and senile (25.8%). Prolonged deviation was the statistically significant factor contributing to final alignment (P = .023). Fourteen of 31 patients had stereoacuity measurement; all achieved a stereoacuity of 3000 seconds of arc. Five of the 14 patients (35.7%) had better than 200 seconds of arc.

CONCLUSIONS

The anatomical results and sensory function of the patients were generally good. When appropriate, surgical intervention to treat strabismus after cataract surgery should be offered, and this is important for restoration of fusion.

Persistent strabismus after cataract extraction

BACKGROUND

Transient ocular misalignment as a complication of parabulbar and peribulbar anesthesia has already been reported in the literature. The aim of our study was to present a case of irreversible iatrogenic vertical strabismus after cataract surgery, which had to be operated on.

METHODS

Clinical and orthoptic evaluation of a female patient with vertical diplopia after phacoemulsification cataract surgery.

RESULTS

One week after the uneventful surgery, a 68-year-old patient complained of a sudden vertical deviation in the operated eye. The patient had not had a history of previous motility disorders. On examination, the patient showed hypertropia in the left eye of 15-20 degrees in primary position. Three and 6 months postoperatively, there was no a spontaneous improvement, while the persistent vertical deviation was 40 prism dioptres. Strabismus surgery was required 1 year after the cataract surgery.

CONCLUSION

Diplopia is a complication of peribulbar anesthesia which could be persistent. The superior and inferior rectus muscle are especially vulnerable. Its occurrence may be technique--related and the incidence increases when hyaluronidase is not available.

Advances in ophthalmic regional anaesthesia

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

Persistent diplopia after retrobulbar anesthesia

PURPOSE

To determine the causative factors of persistent diplopia after retrobulbar anesthesia.

SETTING

Strabismus Section, Department of Ophthalmology, Seoul National University, Seoul, South Korea.

METHODS

Prism and alternate cover tests in the diagnostic positions of gaze and ductions/versions were performed in 28 patients with persistent diplopia 6 months after retrobulbar anesthesia. The Lancaster test, Bielshowsky head tilt test, double Maddox rod test, fundoscopic examination for torsion, forced duction test, force generation test, tensilon test, thyroid function test, and/or orbit computed tomography were performed when necessary.

RESULTS

Most of the patients (26 patients, 93%) did not have diplopia before retrobulbar anesthesia. Of the 14 patients with extraocular muscles imbalance, 12 patients showed vertical rectus overaction (11 superior recti, 1 inferior rectus) and 2 patients, mild vertical rectus underaction. Nine patients were presumed to have a sensory strabismus related to the preoperative poor vision, but this went unnoticed preoperatively. Three patients showed a small vertical deviation without any specific causative factors.

CONCLUSIONS

Fifty percent of the cases of diplopia were associated with either direct trauma or anesthetic myotoxicity to the extraocular muscles, in which overactions were more common than underactions. Thirty-two percent of the patients were presumed to have sensory strabismus, which suggested the importance of preoperative examination for strabismus as well as providing an explanation about the risk of postoperative diplopia before surgery.

Early exploration of diplopia with magnetic resonance imaging after peribulbar anaesthesia

We report the cases of five patients who have experienced postoperative diplopia after cataract surgery under peribulbar anaesthesia and in whom orbital Magnetic Resonance Imaging was performed immediately after the diagnosis. In four patients, the imaging study showed a T2 hyper-intensity signal and swelling of one extraocular muscle that was interpreted as oedema. Therefore, these cases were most probably a result of an accidental i.m. injection of local anaesthetics. In the other patient, the imaging study revealed no abnormality.

Effect of retrobulbar injection of lidocaine on saccadic velocities

PURPOSE

To determine whether exposing the extraocular muscles (EOMs) to lidocaine via retrobulbar injection for cataract surgery has a demonstrable negative effect on subsequent function of the muscle.

SETTING

York Finch Eye Associates, Humber River Regional Hospital, and Toronto Western Hospital Research Institute, Toronto, Ontario, Canada.

METHODS

This study comprised 37 eyes that had phacoemulsification and posterior chamber intraocular lens implantation; 13 eyes had retrobulbar lidocaine with hyaluronidase and 24 eyes, topical anesthesia. The postoperative saccadic velocities were compared with the preoperative velocities using a sensitive recording device. The results were compared within and between the retrobulbar lidocaine and topical anesthesia groups.

RESULTS

No detectable decrement in postoperative saccadic velocities was detected in any patient, and no difference was found between the groups.

CONCLUSIONS

Exposing EOMs to lidocaine for cataract surgery had no detectable negative effect on saccadic velocities 1 week after surgery.

Strabismus after regional anesthesia for cataract surgery

BACKGROUND

An adult strabismus clinic in a regional eye centre provided an opportunity to estimate the risk of postoperative diplopia from regional anesthesia after cataract surgery and to describe the management of these patients.

METHODS

Retrospective cohort analysis. All cases were referred over a 22-month period (November 1997 to September 1999) for investigation of postoperative diplopia after cataract surgery. The surgical and anesthetic records were reviewed to determine the number and location of injections, and the volume and type of regional anesthesia. The evolution and management of patients' diplopia was studied prospectively.

RESULTS

Twenty-one patients (12 women and 9 men aged 63 to 88 [median 76] years) were ascertained with postoperative diplopia. In 11 cases the right eye was affected, and in 10 cases, the left eye. Vertical diplopia occurred most commonly from inferior rectus restriction (16 cases). Three cases resolved without treatment, which indicated that the diplopia was transient. Four patients declined treatment, five required prism in eyeglasses only, and nine required strabismus surgery. One patient required surgery and prism in eyeglasses. Two patients required more than one strabismus operation to relieve the diplopia. For the period of data collection, we estimate the risk of nontransient postoperative diplopia from regional anesthesia as 2.6 cases per 1000 cataract procedures (95% confidence interval 1.9-4.7).

INTERPRETATION

Patients should be forewarned of the risk of diplopia after cataract surgery with regional anesthesia. The treatment of the diplopia may require prism in eyeglasses or strabismus surgery or both.

Vertical diplopia following peribulbar anesthesia: the role of hyaluronidase

PURPOSE

To estimate the incidence of vertical diplopia following peribulbar anesthesia in otherwise uncomplicated cataract surgery and to establish whether the use of hyaluronidase in the peribulbar injection mixture affected the likelihood of this complication.

METHODS

Nine hundred forty consecutive phacoemulsification procedures using peribulbar anesthesia were retrospectively reviewed to identify cases of postoperative vertical diplopia. Case notes were reviewed to establish the nature and timing of the onset of diplopia, the anesthetic technique, and whether hyaluronidase was used. The patterns of progression as demonstrated by serial Hess charts were compared.

RESULTS

There were 6 cases of vertical diplopia (incidence, 0.64%). All showed an immediate postoperative hypertropia in the injected eye changing during a 4- to 6-week period to hypotropia with restriction of upgaze. All applications of anesthesia were administered by consultant anesthetists, associate specialists, or residents under their direct supervision using 25-mm, 25-gauge needles with 2% lidocaine. Hyaluronidase was included in the injection mixture for 435 (46%) of the cases and was not included for 505 (54%) of the cases. All 6 cases of vertical diplopia occurred in the group in which hyaluronidase was not used, which has a significant association (chi-square test, 5.22; P = .023).

CONCLUSION

Hyaluronidase should be included in peribulbar anesthetics to reduce the risk of postoperative vertical diplopia.

Diplopia following cataract extraction

Diplopia following cataract extraction occurs in approximately 1% of cases or less. With over 1.5 million cataract extractions per year, this can lead to a considerable morbidity. It is typically a small vertical deviation and is distressing if unanticipated. The most common etiologies include surgical manipulation of orbital tissue from a bridle suture, extraocular muscle trauma from a retrobulbar needle or anesthetic, and unmasking an underlying strabismus or systemic condition with extraocular muscle involvement. Care must therefore be taken by obtaining a complete preoperative history and examination, document any preexisting strabismus and systemic condition, and avoid any direct extraocular muscle trauma or manipulation.

Anaesthesia-related diplopia after cataract surgery

BACKGROUND

We studied the incidence and clinical characteristics of persistent diplopia related to anaesthesia for cataract surgery in a general hospital.

METHODS

This was a retrospective review of anaesthesia for 3587 cataract surgeries. Of all the cases of diplopia referred to the ocular motility clinic after cataract surgery, those involving anaesthesia-related diplopia lasting longer than 1 month were studied.

RESULTS

During the study period, 3450 cataract surgeries were performed by phacoemulsification and 137 by extracapsular extraction. Retrobulbar block was used in 2024 cases, peribulbar block in 98, topical anaesthesia in 1420 and general anaesthesia in 43. Twenty-six cases of persistent diplopia were found (0.72% incidence), nine of which (0.25%) were considered to be related to anaesthetic factors; five of the latter involved the left eye. Five were caused by paresis of the inferior rectus muscle and three by fibrosis. In one patient, the inferior oblique muscle was affected. Anaesthesia was by retrobulbar block in eight cases (0.39%) and by peribulbar block in one. No diplopia was found in patients who had topical or general anaesthesia. Treatment was with surgery in two patients and with prisms in six. One patient continues to be studied.

CONCLUSIONS

Persistent diplopia can occur after cataract surgery using retrobulbar block predominantly through direct damage to the inferior rectus muscle. The overall incidence of anaesthesia-related diplopia in this series was 0.25%.

Ropivacaine-lidocaine versus bupivacaine-lidocaine for retrobulbar anesthesia in cataract surgery

PURPOSE

To compare the efficacy of ropivacaine mixed with lidocaine and bupivacaine mixed with lidocaine for retrobulbar anesthesia in cataract surgery.

SETTING

Philippine General Hospital, Manila, Philippines.

METHODS

This prospective double-masked study consisted of 80 patients randomized to receive ropivacaine 1%-lidocaine 2% (Group 1) or bupivacaine 0.5%-lidocaine 2% (Group 2) for retrobulbar anesthesia during extracapsular cataract extraction (ECCE). The main outcome measures were frequency of eye pain and amount of globe movement. The degree of pain was scored from 0 to 10 using a visual analog scale. Globe movement in 4 directions of gaze was measured with a ruler.

RESULTS

The number of patients with visual analog system scores greater than zero at 5 minutes after infiltration, 10 minutes after infiltration, intraoperatively, and 1, 2, and 4 hours postoperatively was 0, 0, 0, 1, 18, and 29, respectively, in Group 1 and 1, 1, 0, 1, 21, and 33, respectively, in Group 2. The mean globe movement at 5 minutes, 10 minutes after infiltration, and intraoperatively was 5.1 mm, 3.0 mm, and 0.6 mm, respectively, in Group 1 and 4.9 mm, 3.0 mm, and 0.3 mm, respectively, in Group 2. There were no significant differences in frequency of pain and amount of globe movement between the 2 groups at any time. No adverse reactions developed in either group. The duration of surgery was similar between groups.

CONCLUSION

Ropivacaine mixed with lidocaine and bupivacaine mixed with lidocaine were equally effective in producing ocular analgesia and akinesia for ECCE.

Persistent vertical binocular diplopia after cataract surgery

PURPOSE

To report the incidence of, and factors associated with, persistent vertical diplopia after cataract surgery.

DESIGN

Consecutive interventional case series.

METHODS

Retrospectively, all adult patients examined during a five year, five month period because of new onset persistent (>3 months) vertical binocular diplopia after cataract surgery were analyzed. All patients had their cataract surgery at the same outpatient ophthalmic surgery center, and were referred to the author, enabling calculation of incidence. Trends in anesthesia type and strabismus complications therefrom were also assessed. Comparison was made between ophthalmologist-administered retrobulbar anesthesia versus anesthesia staff-administered retrobulbar anesthesia. Incidence during a period in which hyaluronidase was not incorporated in the retrobulbar anesthetic was calculated.

RESULTS

Persistent vertical diplopia occurred after cataract surgery in 32 (0.18%) of 17,531 eyes that had cataract surgery. No patient whose cataract surgery was conducted with topical anesthesia (3817 eyes) had persistent vertical diplopia, whereas 32 (0.23%) of the 13714 eyes whose cataract surgery was done after retrobulbar anesthesia were affected. No cases of persistent postoperative diplopia were found among 7410 cataract surgery eyes after retrobulbar injection given by one cataract surgeon. There was a threefold greater number of left eyes involved than right eyes (P <.005). No significant (P >.20) increase in cases of persistent vertical diplopia was noted during a period of hyaluronidase shortage.

CONCLUSIONS

In this study, persistent binocular vertical diplopia after cataract surgery occurred in 0.23% of cases in which retrobulbar anesthesia was performed. No cases were found after topical anesthesia. Occurrence may be technique-related.

Second cluster of strabismus cases after periocular anesthesia without hyaluronidase

We describe a second cluster of cases of iatrogenic strabismus that occurred in clinical practices following cataract surgeries that occurred in 2000 when hyaluronidase was once again unavailable for use in periocular anesthetic regimens. Twelve cases of transient or permanent strabismus were referred by 4 anterior segment surgeons who had no previous cases of postcataract strabismus when performing periocular injections with hyaluronidase. The charts of the patients were reviewed retrospectively. Recurrence of an increase in postoperative strabismus when hyaluronidase became unavailable for a second time supports the concept that this enzyme may be more important than previously suspected in preventing damage to the extraocular muscles after periocular anesthetic injections.

Diplopia and ptosis following injection of local anesthesia without hyaluronidase

In a university ophthalmology department, a cluster of postoperative diplopia and ptosis cases occurred in the initial 3 months after hyaluronidase (Wydase) became unavailable for use with injection anesthesia. These cases suggest that hyaluronidase, when used with injection anesthesia, may protect extraocular muscles and nerves from the toxic effects of local anesthetic agents. The spreading action of hyaluronidase facilitates uniform diffusion of anesthetic agents. This prevents elevated extracellular tissue pressure, a cause of ischemic damage to extraocular muscles or nerves. Hyaluronidase may also prevent focal accumulations and concentrations of local anesthetic agents, which at high enough levels may cause myotoxic or neurotoxic damage, fibrosis, and contracture of extraocular muscles or nerves.

Anesthesia for intraocular surgery

Surgeons must decide on the type of anesthesia to use when performing cataract surgery. These "viewpoints" articles provide a well-balanced discussion offering the pros and cons of both topical anesthesia and retrobulbar/peribulbar injection. Dr. Dutton gives an overview of both techniques, focusing on relevant orbital anatomy. Drs. Hassan, Edelhauser and Kim, review the various types of topical anesthesia currently in use, and Drs. Spriggs and Broocker examine retrobulbar and peribulbar injections. Both techniques are associated with advantages and risks, so each surgeon must decide which technique is best suited for his or her own practice.