Role of Hyaluronidase in Diplopia after Peribulbar Anesthesia for Cataract Surgery

Frequency and Etiologies of Visual Disturbance After Cataract Surgery Identified in Neuro-Ophthalmology Clinics

BACKGROUND

To identify the frequency and etiologies of visual disturbances after cataract surgery in patients referred to Neuro-ophthalmology.

METHODS

This study is a retrospective chart review. Records of patients 18 years and older referred to neuro-ophthalmology clinics for new-onset visual disturbances within 6 months of cataract surgery were reviewed. Those with pre-existing neuro-ophthalmic disorders, combined intraocular procedures with cataract surgery, or inadequate follow-up were excluded. The main outcome measures were frequency and etiologies of visual disturbances after cataract surgery. Secondary analyses of a cohort of patients who had cataract surgery at our institution were performed to determine the frequency and etiology of visual disturbances after uneventful cataract surgery.

RESULTS

One hundred seventy-three patients met the inclusion criteria (internal referral: 36/173, from outside surgeons: 137/173). Sixty-one percent (106/173) were newly diagnosed with neuro-ophthalmic etiologies, including 21% (36/173) with afferent and 40% (70/173) with efferent disorders. Thirty-six percent (62/173) of patients had non neuro-ophthalmic causes and 3% (5/173) had systemic conditions responsible for visual disturbances postoperatively. Decompensated strabismus causing diplopia was the most common neuro-ophthalmic diagnosis after cataract surgery (50%, 53/106). Of the 13,715 patients who had cataract surgery performed at our institution over a 9-year period, 20 of 36 patients referred for visual disturbances were identified with neuro-ophthalmic etiologies of which 85% (17/20) had postoperative diplopia.

CONCLUSIONS

In our study, decompensated strabismus causing diplopia was the most common neuro-ophthalmic visual disturbance after cataract surgery. Detailed history and ocular alignment should be assessed before cataract surgery to identify patients with the risk.

Role of hyaluronidase as an adjuvant in local anesthesia for cataract surgery

Cataract surgery ranks among the commonest procedures performed worldwide. Approximately 51% of blindness worldwide is related to cataracts, affecting about 65.2 million people worldwide and more so in developing countries. Over the years, there has been a significant evolution in the surgical techniques of cataract extraction. The advancement in phacoemulsification machines, phaco-tips, and the availability of ophthalmic viscoelastic devices have played a substantial role in cataract surgery such that they are faster and more controlled than before. Similarly, anesthetic techniques in cataract surgery have advanced significantly from retrobulbar, peribulbar, and sub-Tenon's blocks to topical anesthesia. Though topical anesthesia eliminates the possible complications of injectable anesthesia, it is not suitable for use in uncooperative, anxious patients, pediatric age groups, and patients with cognitive disabilities. Hyaluronidase is an enzyme that breaks down hyaluronic acid in the retrobulbar tissue, facilitating uniform diffusion of the anesthetic drug and hastening the onset of anesthesia and akinesia. Hyaluronidase has been used in the last 80 years successfully as an adjuvant in retrobulbar, peribulbar, and sub-Tenon's blocks. Initially, the hyaluronidase enzyme was animal-derived and of bovine and ovine sources. Recombinant human-derived hyaluronidase, which has lesser allergic reactions, impurities, and toxicity, is now available. There is conflicting evidence regarding the efficacy of hyaluronidase as an adjuvant in retrobulbar and peribulbar blocks. This article summarizes a brief review of the literature on the role of hyaluronidase as an adjuvant in local anesthetic blocks in ophthalmic surgeries.

Brown Syndrome from Local Anesthesia for Inferior Orbital Fat Decompression

Patient: Female, 36-year-old

Final Diagnosis: Acquired Brown syndrome

Symptoms: Diplopia • vertical diplopia

Medication: —

Clinical Procedure: Local anesthesia • orbital fat decompression

Specialty: Ophthalmology

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.

Methods

In this double blinded randomized study, 202 patients reporting for surgery for senile cataract in their first eye under regional ocular anesthesia without pre-existing extra ocular movement restriction were randomly divided into 2 groups: Group 1 – anesthesia without hyaluronidase, Group 2 – anesthesia with 50 IU/ml Hyaluronidase. Peribulbar block with 5 ml of anesthetic mixture of 2% lignocaine with 1:200000 adrenaline and 0.5% bupivacaine with or without hyaluronidase was performed with 3 ml deposited in the infero-medial quadrant and 2 ml in the supero-medial quadrant followed by ocular massage. Surgeons’ score for akinesia, patients’ score for analgesia, augmentation of block if any and extra ocular movements on first post-operative day were compared between the groups.

Results

There was no statistically significant difference between the two groups in akinesia (p = 0.22, 0.68 and 0.98), analgesia (p = 0.44 and 0.09) or requirement of anesthetic augmentation (p = 0.3). Extraocular movement restriction was not noted in any patient. Onset of akinesia and analgesia was earlier in Group 2 (p = 0.004 and p = 0.005 respectively).

Conclusions

Hyaluronidase is not an essential adjuvant for peribulbar block for cataract surgeries. Appropriate deposition of a smaller volume of anesthetic agent and adequate ocular massage provide adequate and safe anesthesia.

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.

Pain Levels after Local Anaesthetic with or without Hyaluronidase in Carpal Tunnel Release: A Randomised Controlled Trial

Purpose. Hyaluronidase is an enzyme that temporarily liquefies the interstitial barrier, allowing easy dispersal of local anaesthetic through cleavage of tissue planes. This prospective, blinded, randomised controlled study investigates the utility of adding hyaluronidase to local anaesthetic in the setting of carpal tunnel release. Methods. 70 consecutive carpal tunnel release patients were recruited and randomised into a control group only receiving local anaesthetic and a hyaluronidase group receiving both hyaluronidase and local anaesthetic. Pain scores were rated using the visual analogue scale (VAS) by patients immediately after local anaesthetic injection and again immediately after the carpal tunnel release. Results. Preoperative VAS scores, taken after local anaesthetic injection, were greater than postoperative VAS scores. Postoperative VAS scores were significantly lower in the hyaluronidase group and tourniquet times were significantly shorter in the hyaluronidase group. Conclusion. Hyaluronidase addition to local anaesthetic in carpal tunnel release resulted in significant reductions in operative time and pain immediately after operation.

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.

A cadaveric feasibility study of the intraorbital cannula injections of hyaluronidase for initial salvation of the ophthalmic artery occlusion

BACKGROUND

Phthisis bulbi may follow cosmetic filler injections. Early attempts to inject hyaluronidase into the orbit after detection of devastating signs and symptoms may potentially mitigate the complications.

METHODS

Cannula routes along the orbital walls were studied. Depths of injections were determined in 30 dry skulls. Deep cannula insertions were carefully performed while avoiding exiting the orbit. Forty-six cadaveric orbits with intravascular latex injection were dissected to determine injection techniques, to verify structures at risk along the routes, and to evaluate substance dispersion.

RESULTS

The limited depths of the superior, lateral, medial, and inferior injection routes were 4.2, 3.8, 3.6, and 2.5 cm respectively, while the orbital width was 3.9 cm. The superior parasagittal injection was effective and rarely tears the superior ophthalmic vein, artery, and the optic nerve. The medial injection should be avoided because it may injure the lacrimal sac, the ophthalmic artery, and the optic nerve. Without limited depth, the lateral injection may damage the lacrimal gland and artery and proceeds to damage the optic nerve. The inferior parasagittal injection tends to exit into the infratemporal fossa but the inferior oblique injection may be safer and effective but more complicate with the depth of 4.2 cm.

CONCLUSION

The superior parasagittal injection is a recommended simple technique with a minimal chance of vascular injury. The inferior oblique injection requires more skill but it may be safer because of the lower position. For safety reasons, depth of each cannula insertion should not exceed the orbital width.

NO LEVEL ASSIGNED

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Overexpression and Enzymatic Assessment of Antigenic Fragments of Hyaluronidase Recombinant Protein From Streptococcus pyogenes

BACKGROUND

Hyaluronidase catalyzes the hydrolysis of hyaluronan polymers to N-acetyl-D-glucosamine and D-glucuronic acid. This enzyme is a dimer of identical subunits. Hyaluronidase has different pharmaceutical and medical applications. Previously, we produced a recombinant hyaluronidase antigenic fragment of Streptococcus pyogenes.

OBJECTIVES

This study aimed to improve the protein production and purity of hyaluronidase recombinant protein from S. pyogenes. In addition, the enzymatic activity of this protein was investigated.

MATERIALS AND METHODS

The expression of hyaluronidase antigenic fragments was optimized using IPTG concentration, time of induction, temperature, culture, and absorbance of 0.6-0.8-1 at 600 nm. Afterwards, the expressed proteins were purified and the enzymatic activity was assessed by turbid metric method.

RESULTS

Data indicated that maximum protein is produced in OD = 0.8, 0.5 mM Isopropyl β-D-1-thiogalactopyranoside (IPTG), 37ºC, NB 1.5x, without glucose, incubated for overnight. The enzymatic activity of the recombinant protein was similar to the commercial form of hyaluronidase.

CONCLUSIONS

The results showed that an antigenic fragment of the recombinant hyaluronidase protein from S. pyogenes has a considerable enzymatic activity. It can be suggested to use it for medical purposes. In addition, applications of bioinformatics software would facilitate the production of a smaller protein with same antigenic properties and enzymatic activity.

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.

[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.

Recombinant human hyaluronidase (rHuPH20): an enabling platform for subcutaneous drug and fluid administration

The extracellular matrix is a significant barrier to the effective subcutaneous delivery of many drugs, limiting both pharmacokinetic parameters and injection volumes. The space outside adipocytes in the hypodermis is not a fluid, but rather a solid extracellular matrix of collageneous fibrils embedded within a glycosaminoglycan-rich viscoelastic gel that buffers convective forces. The extracellular matrix limits the volume of drug that can be injected at a single site, as well as the rate and amount that reach the vascular compartment. A fully human recombinant DNA-derived hyaluronidase enzyme (rHuPH20) has been developed to leverage the historical efficacy of animal testes extract-derived spreading factors to reversibly modify the hypodermis, in light of discovery of the human hyaluronidase gene family. The application of this technology to increase both injection volumes and bioavailability from subcutaneous injection may overcome some key limitations of this route of administration in multiple settings of care.

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.