Bupivacaine injection to treat exotropia and esotropia

Applications of bupivacaine in the non-surgical treatments of strabismus: a review

Bupivacaine (BUP) is an anesthetic from the family of aminoacyl anesthetics and has the highest myotoxicity among other groups of anesthetics. Intramuscular injection of BUP first causes acute libriform lysis and subsequently with the regeneration process, stronger myofibrils are formed within 3-4 weeks. Satellite cells, which are actually myogenic stem cells, are preserved in the early stage and during the destruction of muscle fibers. In fact, these cells are responsible for the subsequent regeneration of fibers. BUP is one of the few medicines that is able to increase muscle strength. In animal studies on rabbits, a decrease has been observed in the diameter of the global layer in the first week and an increase in type-I myosin occurs after 60 days, especially in the global muscle layer. There are numerous studies according to BUP injection for the non-surgical management of horizontal strabismus. To intensify the effects of the injection, botulinum toxin injection can also be used simultaneously in the antagonist muscles. In general, although the rate of improvement in strabismus varied among different studies, BUP injection alone corrects about 5-8 prism diopters. Together with botulinum toxin, BUP corrects about 15 prism diopters. The stability of this improvement is up to 10 years after injection. No significant difference has been observed in response rate between patients with esotropia and exotropia. Unlike the large molecule of botulinum toxin, which spreads slowly to its site of action, the BUP molecule is small and must be in direct contact with myofibrils before absorption into the bloodstream to exert its effect. Therefore, the injection volume should be about 3 cc with a concentration of 0.75 g per deciliter. Although BUP is promising non-surgical strabismus management, especially in small angle and residual horizontal strabismus, however, it has its own limitations. The need for direct infusion of a relatively large volume of BUP may be one of its major drawbacks that limits its usage in an office method.

Treatment of convergence insufficiency type intermittent exotropia with bupivacaine injection to the medial rectus combined with lateral rectus recession

PURPOSE

To evaluate the outcomes of combined bupivacaine HCL (BPX) injection in the medial rectus (MR) muscle with recession of the lateral rectus muscle in the treatment of convergence insufficiency-type intermittent exotropia (CI-IXT).

METHODS

The medical records of patients who underwent combined injection-recession treatment from January 2019 to January 2020 for CI-IXT were reviewed retrospectively along with a group of age-matched controls with IXT without CI who underwent only unilateral LR recession during the same period. The following data were extracted from the record: age at surgery, average follow-up period, angle of deviation at distance and near and the difference between them before and after surgical procedure, correction of near and distance deviations, and recession dosage. Successful outcome was defined as a distance deviation in primary gaze between ≤10^Δ of exophoria/tropia and ≤5^Δ of esophoria/tropia.

RESULTS

A total of 10 patients and 20 controls were included. Average follow-up was 13.9 ± 3.67 months in the BPX group and 15.9 ± 3.61 months in the control group (P = 0.17). Postoperative distance deviation measured 8.30^Δ ± 5.88^Δ in the BPX group and 14.67^Δ ± 9.83^Δ in the control group (P = 0.80). Distance-near differences were significantly reduced in the CI-IXT group receiving BPX, by a mean of 6.60^Δ, from a preoperative mean of 10.50^Δ ± 3.65^Δ to 3.90^Δ ± 3.26^Δ (P < 0.01).

CONCLUSIONS

BPX injection combined with unilateral lateral rectus recession yields outcomes comparable to bilateral lateral rectus recession for distance deviations, and results in reduction of the distance-near difference in the angle of exotropia.

The efficacy of bupivacaine for the treatment of strabismus

INTRODUCTION

Bupivacaine (BPX) is a widely used local anesthetic. Ophthalmologists have found a unique use of BPX to alter the elasticity and contractile properties of extraocular muscles to straighten strabismus. The utilization of BPX to treat strabismus has been well documented. The purpose of this review is to examine the overall efficacy of BPX when used in isolation for the treatment of strabismus, based on the published literature.

METHODOLOGY

A literature search was carried out to identify papers published between the years 1980 and 2021, which examined the impact of BPX as a stand-alone treatment for strabismus.

RESULTS

Eight articles were identified as matching the inclusion criteria. The authors reported that volumes of ≤1.00 mL are unlikely to be significant enough to improve ocular alignment and increasing volume strength is associated with greater changes in ocular alignment. The overall change in ocular alignment varied from 0-16PD between the different studies included, with similar effects being noted for deviations between 10 and 20PD and deviations as large as 55PD. It has been documented that there is no significant difference in the outcomes of BPX treatment for esotropia and exotropias, but some clinical differences have been noted with esotropia (or the lateral rectus) responding better to BPX. Bupivacaine has been demonstrated to be less effective in patients with chronic nerve palsies. All but one author documented increases in the injected muscle's volume and maximum cross-sectional area from month one to three followed thereafter by a gradual decrease in both measurements. It was noted that despite the reduction in both measurements, the change in ocular alignment continued to show improvements. No sight-threatening or persistent complications were reported within any of the studies or case reports included within this review. In the interest of patient experience, the majority of patients reported that BPX improved their eye alignment, while a third reported feelings of discomfort during the procedure.

CONCLUSION

Bupivacaine is a viable option for the treatment of small angle deviations and is not recommended for use in long-standing cranial nerve palsies or those associated with atrophy. Care is needed in determining the required dose to avoid the need for re-injection and impacting patient experience.

Evaluation of temporal muscle trophism in relation to the manipulation time and infiltration of 0.5% isobaric bupivacaine through a pterional approach

INTRODUCTION

There are different techniques for the reconstruction of the temporal muscle (TM) in the pterional approach (PA) in order to avoid and reduce atrophy, it has not been able to avoid it in its entirety. The administration of bupivacaine generates regeneration of muscle fibres. There are no studies in the medical literature that evaluate the time of TM manipulation and the use of bupivacaine for the treatment of atrophy after pterional approach, the present investigation aim is to describe the effects of these variables.

PATIENT AND METHODS

Longitudinal study, including patients from 18-80 years old with pterional approach at 2016-2017. We evaluated the effects of the TM manipulation times and the administration of 0.5% bupivacaine on the trophism and function of TM.

RESULTS

Twenty-nine patients underwent a PA; 16(55.17%) count with criteria for 0.5% bupivacain infiltration. We found a negative correlation between manipulation times and trophism, with no statistically significance (p>.05). We evaluated presurgical and postsurgical index of Helkimo and Fonseca's index, finding an increase of disfunction with statistically significance (p<.05). In patients who were infiltrated with 0.5% bupivacaine we observed a mean difference in the TM's trophism of 0.275±1.18mm, in contrast with no infiltrated which was 2.39±1.30mm (t[27] = -5.118, p=.0001).

CONCLUSIONS

The manipulation of the TM during a pterional approach conditioned an impact on the quality of life according to the disfunction indexes, due to atrophy. This investigation exhibits that de administration of 0.5% bupivacaine during surgery offers a decrease in the TM atrophy.

Bupivacaine Injection for Management of Lagophthalmos Due to Long-Standing Idiopathic Facial Nerve Palsy

PURPOSE

To report the results of bupivacaine injection into the orbicularis oculi muscle to treat lagophthalmos in patients with long-standing Bell palsy.

METHODS

In this prospective interventional case series, bupivacaine, 5 ml of a 0.750% solution, was injected into the preseptal and pretarsal area of the orbicularis oculi in each of 10 patients with idiopathic peripheral facial nerve palsy. The measures of vertical eyelid apertures during open and closed eyes were made before the procedure and 1, 3, and 6 months after injection.

RESULTS

A total of 10 eyes including 2 men and 8 women with an average age of 43 years (26-64 years) were studied. The mean amount of lagophthalmos before injection and after 6 months of follow up were 3.9 mm and 2.3 mm, respectively (p = 0.01)). The mean amount of corneal exposure before injection and after 6 months of follow up was 1.05 mm and 0.25 mm, respectively (p < 0.01). The mean scleral show in open eyes before injection and after 6 months of follow up were 1.20 mm and 0.75 mm, respectively (p = 0.08). The mean scleral show in closed eyes before injection and after 6 months of follow up were 1.95 mm and 1.15 mm, respectively (p = 0.01). All the patients reported significant decrease in epiphora.

CONCLUSION

Bupivacaine injection in the paretic orbicularis oculi muscle improves eyelid closure and lagophthalmos and epiphora.

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.

The effects of bupivacaine injection and oral nitric oxide on extraocular muscle in the rabbit

AIM

Nitric oxide (NO) plays a key role in muscle regeneration, which is the primary response, observed during bupivacaine-induced extraocular muscle (EOM) hypertrophy. Our aims were to investigate the effects of bupivacaine injection into the rabbit EOM and the interaction with NO.

MATERIALS AND METHODS

Superior rectus (SR) muscles of 24 New Zealand albino rabbits were studied. Single muscle twitch tension (SMTT) and tetanic muscle tensions at 50, 75, and 100 Hz were recorded using a 15 V stimuli. The rabbits were equally allocated into three groups. Measurements were performed without any drug treatments in group 1. In groups 2 and 3, bupivacaine, 0.5 ml of a 0.50 % solution, was injected into the EOM, and after 21 days, measurements were performed. Oral isosorbide dinitrate (NO donor) at 20 mg/day was given each day prior to measurements in group 3.

RESULTS

SMTTs were 69.9 (66.7-77.6), 187.7 (114.9-252.1) and 204.2 (135.3-311.6) mg in groups 1, 2, and 3 respectively. SMTTs for both groups 2 and 3 were significantly higher than that for group 1 (p < 0.05). Compared with group 1, group 2 exhibited a 3.8-11.7 % increase in the tetanic tensions at 50, 75, and 100 Hz, but none of these differences were statistically significant. The increase was 47.5-137.5 % in group 3 relative to group 2, and the differences were statistically significant except at 100 Hz. The enlargement of the muscle fibers after bupivacaine injection was shown histopathologically.

CONCLUSION

Bupivacaine injection increased the EOM tension in rabbits to some extent. NO augmented the effect of bupivacaine.