A novel hybrid BonT-A and hyaluronic acid cannula-based technique for eyelid ptosis and periorbital rejuvenation

BACKGROUND

Eyelid ptosis is characterized by an inferior displacement of the upper eyelid when the eye assumes its primary position. Besides its aesthetic implications, ptosis can also adversely affect visual acuity.

OBJECTIVE

This study aimed to evaluate the simultaneous administration of IncobotulinumtoxinA (IncoBonTA) and hyaluronic acid effect in eyelid ptosis and ocular rejuvenation.

METHODS

A novel, non-surgical technique for eyelid ptosis management involving IncoBonTA and hyaluronic acid the co-administration within a single syringe, and applied using a cannula.

RESULTS

The dual action of IncoBonTA and hyaluronic acid in conjunction with the exact injection sites approaches improves overall aesthetic outcomes but also optimizes the restoration of eyelid functionality in palpebral ptosis.

CONCLUSIONS

The functional balance achieved among the contributory muscles-primarily the orbicularis oculi (OO) and its antagonists, the frontal muscle and levator palpebrae superioris (LPS), yields to both, cosmetic and functional.

Diagnostic yields and clinical features of ocular myasthenia gravis

To investigate clinical features and diagnosis process of ocular myasthenia gravis (OMG) in ophthalmology department.A total of 36 patients with ptosis or diplopia who had follow-up for at least 3 months between March 2016 and December 2019 were included in this study. Clinical symptoms of patients and the test results were analyzed. According to the positivity of serologic test, these patients were divided into 2 groups (confirmed OMG and possible OMG with relief of symptoms after antimyasthenic treatment) for comparison.Ptosis was present in 12 (33.33%) patients, diplopia was present in 14 (38.89%) patients, and both ptosis and diplopia were present in 10 (27.78%) patients. Acetylcholine receptor auto-antibody (AchR Ab) was positive in 14 (38.89%) of 36 patients and ice test was positive in 15 (71.43%) of 21 patients with ptosis. Unequivocal response to pyridostigmine was observed in 31 (86.11%) patients. For seropositive cases, AchR Ab titer was significantly higher in the group with 2 clinical symptoms than that in the 1 clinical symptom (P = .011).This study presents the usefulness and diagnostic validity of antimyasthenic treatment for OMG, especially seronegative OMG, with detailed symptom analysis.

Botulinum Toxin Injection for the Treatment of Strabismus: A Report by the American Academy of Ophthalmology

PURPOSE

To review the available evidence comparing the effectiveness of extraocular muscle botulinum toxin type A (BTXA) injection with eye muscle surgery for restoring ocular alignment in children and adults with nonparalytic, nonrestrictive horizontal strabismus.

METHODS

Literature searches in the PubMed Cochrane Library, and clinical trial databases with no date restrictions, but limited to articles published in English, were conducted last on January 10, 2021. The searches yielded 515 citations, 40 of which were reviewed in full text by the first author. Fourteen articles met the criteria for inclusion (randomized or nonrandomized comparative studies, or case series with a minimum 50 patients; evaluating extraocular muscle BTXA injection for initial or repeat treatment of horizontal, nonparalytic, nonrestrictive strabismus; with at least 6 months of follow-up) and were graded by a methodologist.

RESULTS

The 14 included studies consisted of 2 randomized clinical trials, 3 nonrandomized comparative studies, and 9 case series. All 5 comparative studies were graded level II evidence, and the 9 case series were graded level III evidence. Successful motor outcomes after BTXA injection were relatively consistent across 4 of the 5 comparative studies at 60%, when adjustment was made for differential selection bias in 1 of the studies. In the 4 studies, successful motor outcomes after surgery ranged from 66% to 77% with a mean follow-up of 23 to 75 months, and the outcomes were not significantly different from those after BTXA injection. In the fifth level II study, success was significantly higher with BTXA injection than with surgery (94% vs. 72%). The level III BTXA case series demonstrated higher motor success rates of 87% to 89% when children were treated in 2 muscles at a time; rates were lower in adults treated with single-muscle BTXA injection.

CONCLUSIONS

Extraocular muscle injection of BTXA achieves a high rate of successful motor alignment, comparable with that achieved after eye muscle surgery for nonparalytic, nonrestrictive horizontal strabismus. Good alignment may require multiple BTXA injections, and it is not yet clear whether sensory outcomes are equivalent for BTXA injections versus eye muscle surgery in young children.

Quantification of Global Ocular Motility Impairment in Graves' Orbitopathy by Measuring Eye Muscle Ductions

Background: The overall changes of ocular motility in Graves' orbitopathy (GO) are not easily quantifiable with the methods currently available, especially in clinical studies. The aim of the present study was to calculate parameters that quantify the changes of ocular motility in GO in relation to the Gorman score for diplopia. Methods: We studied 100 GO patients (Group 1) and 100 controls (Group 2). We also included 30 patients treated with intravenous methylprednisolone (iv-MP), assessed at baseline and after 12 and 24 weeks (Group 3), and 66 patients submitted to squint surgery, assessed at baseline and after 12 weeks (Group 4). Ocular ductions were measured in four gaze directions by a perimeter arc and were used to calculate a total motility score (TMS) as the sum of ductions in each direction; a biocular TMS (b-TMS) as the sum of the TMS of two eyes; and an asymmetry ratio (AR) as the sum of the differences of the corresponding ductions between the two fellow eyes divided by the mean difference found in controls. Quality of life was accessed by a specific questionnaire (Graves' orbitopathy quality of life [GO-QoL] questionnaire). Results: TMS and b-TMS were lower, while AR was higher, in Group 1 compared with controls (p < 0.001). In Group 1, TMS and b-TMS were inversely correlated with the Gorman score (p < 0.001) and AR was higher in patients with constant diplopia compared with the others (p < 0.001). In Group 3, TMS and b-TMS increased after treatment in responders to iv-MP (p < 0.001). In Group 4, TMS and b-TMS improved in all patients after surgery (p < 0.01), while AR and GO-QoL score improved only in those without residual constant diplopia (p < 0.001). Conclusion: We describe a quantitative method to assess eye motility dysfunction in any stage of GO to be used as an outcome measure in clinical studies.

Botulinum toxin injection without electromyographic guidance in consecutive esotropia

Purpose

To investigate the efficacy of botulinum toxin injection without electromyographic guidance for the treatment of consecutive esotropia.

Methods

A retrospective study was performed on 49 subjects with consecutive esotropia who received botulinum toxin injection in the medial rectus muscles without the use of electromyographic guidance. Treatment was considered successful if the final ocular alignment was orthotropic or esodeviation was ≤10 prism diopters (PD) during distant fixation.

Results

The mean age was 15.2 ± 8.3 years. The mean esodeviation before injection was 21.8 ± 9.1 PD at distance and 21.3 ± 8.3 PD at near. The mean number of injections per patient was 1.3 ± 0.7, and 46 patients (93.9%) received two or fewer injections. At 6 months after the final injection, the mean angle of esodeviation was 7.3 ± 6.0 PD at distance and 7.5 ± 6.6 PD at near (all p<0.001), and 69.4% showed successful alignment. By multivariate analysis, an initial postoperative esodeviation of ≤18 PD at one month after exotropia surgery was considered to be a predictive factor for successful botulinum toxin injection (P = 0.007). Vertical deviation and/or ptosis occurred in 4 patients (8.2%) at two weeks after injection, which all resolved within three months. There was no recurrence of exotropia up to the final follow-up examination.

Conclusion

Botulinum toxin injection without electromyographic guidance is safe and effective in the treatment of consecutive esotropia without causing recurrent exotropia. Successful botulinum toxin injection is likely in patients with an initial postoperative esodeviation of 18PD or less at one month after exotropia surgery.

Botulinum toxin in the treatment of partially accommodative esotropia with high AC/A ratio

Purpose

To study the outcome of botulinum toxin (BTX) treatment (group 1) in partially accommodative esotropia with high accommodative convergence/accommodation (AC/A) ratio, in comparison with bilateral medial rectus muscles recessions and posterior fixation (group 2).

Methods

In a retrospective comparative study, children aged 3–8 years old treated between 2011 and 2016, with partially accommodative esotropia with high AC/A ratio, deviation at distance of 10 prism diopters or more, and at least 1 year of follow-up, were included. Visual acuity, alternate prism and cover test, stereoacuity, biomicroscopy, and cycloplegic retinoscopy were carried out at initial, baseline visit, 6 months and 1 year after BTX injection or surgery. Main outcome variables were deviation at distance and near, improvement in stereoacuity, and percentage of success. We used multiple regression or proportional odds analysis to control for potential confounding variables.

Results

Of 95 patients, 84 were eligible, 48 children in group 1 and 36 in group 2. Deviation and stereoacuity were similar in the two groups at 6 months, but significantly better in the BTX group at 1 year (median distance deviation 0 prism diopters vs 5 prism diopters, p<0.01), although differences were not clinically relevant. Percentage of success was also significantly better only at 1 year (93% vs 72%, p = 0.01). Change in distance-near disparity was not significantly different in the two groups in the period of study.

Conclusions

Botulinum toxin could be superior to, or as effective as surgery, at middle term, in the treatment of partially accommodative esotropia with high AC/A ratio.

Vigabatrin-Induced Retinal Functional Alterations and Second-Order Neuron Plasticity in C57BL/6J Mice

Purpose

Vigabatrin (VGB) is an effective antiepileptic that increases concentrations of inhibitory γ-aminobutyric acid (GABA) by inhibiting GABA transaminase. Reports of VGB-associated visual field loss limit its clinical usefulness, and retinal toxicity studies in laboratory animals have yielded conflicting results.

Methods

We examined the functional and morphologic effects of VGB in C57BL/6J mice that received either VGB or saline IP from 10 to 18 weeks of age. Retinal structure and function were assessed in vivo by optical coherence tomography (OCT), ERG, and optomotor response. After euthanasia, retinas were processed for immunohistochemistry, and retinal GABA, and VGB quantified by mass spectrometry.

Results

No significant differences in visual acuity or total retinal thickness were identified between groups by optomotor response or optical coherence tomography, respectively. After 4 weeks of VGB treatment, ERG b-wave amplitude was enhanced, and amplitudes of oscillatory potentials were reduced. Dramatic rod and cone bipolar and horizontal cell remodeling, with extension of dendrites into the outer nuclear layer, was observed in retinas of VGB-treated mice. VGB treatment resulted in a mean 3.3-fold increase in retinal GABA concentration relative to controls and retinal VGB concentrations that were 20-fold greater than brain.

Conclusions

No evidence of significant retinal thinning or ERG a- or b-wave deficits were apparent, although we describe significant alterations in ERG b-wave and oscillatory potentials and in retinal cell morphology in VGB-treated C57BL/6J mice. The dramatic concentration of VGB in retina relative to the target tissue (brain), with a corresponding increase in retinal GABA, offers insight into the pathophysiology of VGB-associated visual field loss.

The Use of Botulinum Toxin in Strabismus Treatment

There is a long and extensive experience with the use of Botulinum Toxin type A (BoNT-A) injection in the treatment of different types of strabismus and oculomotor palsies. The frequency of its use varies depending on the country and institution. It is a short procedure, may reduce general anesthesia exposure, causes minimal scarring compared to surgery, and can be proposed as an early treatment in unstable strabismus. Over many years, the experience of using BoNT-A indications has been refined and new applications have been reported. The use of BoNT-A in the postoperative period, after strabismus surgery or during surgery, can also be beneficial.

A Rare Case of Mixed Adenoneuroendocrine Carcinoma (MANEC) of the Gastroesophageal Junction with HER2/neu Overexpression and Distinct Orbital and Optic Nerve Toxicity after Intravenous Administration of Cisplatin

BACKGROUND

Mixed adenoneuroendocrine carcinomas (MANECs) are rare malignancies with both neuroendocrine and non-neuroendocrine components. To date, the prognosis of gastroenteropancreatic MANECs remains dismal, and treatment options are mainly based on guidelines for the treatment of pure neuroendocrine carcinomas or small cell lung cancer. Established first-line therapy in the metastatic situation is cisplatin and etoposide. Platinum derivatives are known to cause a variety of side effects also involving the visual system. Severe orbital and optic nerve toxicities have been described mainly after intracarotid infusion of cisplatin.

CASE REPORT

Herein we report a rare case of a 60-year-old male patient suffering from MANEC of the gastroesophageal junction with HER2/neu overexpression who developed severe orbital and ocular neurotoxicity (grade 3 according to CTCAE v4.03) after intravenous cisplatin.

CONCLUSION

We discuss diagnostic approaches and differential diagnoses in this clinical situation. Before starting treatment with intravenous and topical steroids, it is crucial to rule out meningeal and cerebral spread as well as paraneoplastic and endocrine syndromes.

Complete ophthalmoplegia in Ipilmumab and Nivolumab combination treatment for metastatic melanoma

Ipilimumab and Nivolumab are novel monoclonal antibodies that have recently been used successfully for treatment of metastatic melanoma. Ipilimumab is a human monoclonal antibody against Cytotoxic T Lymphocyte Antigen 4 (CTLA4) receptor, which suppresses T-cell proliferation and stimulates an inflammatory response against cancer cells. Nivolumab is an IgG4 monoclonal antibody against the cytotoxic T lymphocyte associated programmed death 1 receptor (PD-1). Ipilimumab and Nivolumab combination treatment has been shown to induce remission and prolong survival in patients with metastatic melanoma. The side effect profile of these medications has not been well studied. One entity of the side effects reported in the literature is immune-related adverse events (irAEs). There have been few case reports where these events were serious and irreversible. In this case report, we describe a fatal and severe diffuse panmyositis that involved the cardiac, respiratory, and extraocular muscles in a patient with metastatic melanoma secondary to combination treatment with Ipilimumab/Nivolumab.

Changing muscle function with sustained glial derived neurotrophic factor treatment of rabbit extraocular muscle

Recent microarray and RNAseq experiments provided evidence that glial derived neurotrophic factor (GDNF) levels were decreased in extraocular muscles from human strabismic subjects compared to age-matched controls. We assessed the effect of sustained GDNF treatment of the superior rectus muscles of rabbits on their physiological and morphological characteristics, and these were compared to naïve control muscles. Superior rectus muscles of rabbits were implanted with a sustained release pellet of GDNF to deliver 2μg/day, with the contralateral side receiving a placebo pellet. After one month, the muscles were assessed using in vitro physiological methods. The muscles were examined histologically for alteration in fiber size, myosin expression patterns, neuromuscular junction size, and stem cell numbers and compared to age-matched naïve control muscles. GDNF resulted in decreased force generation, which was also seen on the untreated contralateral superior rectus muscles. Muscle relaxation times were increased in the GDNF treated muscles. Myofiber mean cross-sectional areas were increased after the GDNF treatment, but there was a compensatory increase in expression of developmental, neonatal, and slow tonic myosin heavy chain isoforms. In addition, in the GDNF treated muscles there was a large increase in Pitx2-positive myogenic precursor cells. One month of GDNF resulted in significant extraocular muscle adaptation. These changes are interesting relative to the decreased levels of GDNF in the muscles from subjects with strabismus and preliminary data in infant non-human primates where sustained GDNF treatment produced a strabismus. These data support the view that GDNF has the potential for improving eye alignment in subjects with strabismus.

The Effect of Botulinum Toxin Augmentation on Strabismus Surgery for Large-Angle Infantile Esotropia

PURPOSE

To determine whether botulinum toxin augments the effect of strabismus surgery in pediatric patients with large-angle infantile esotropia.

DESIGN

Retrospective, comparative, case series.

METHODS

Setting: Tertiary-care pediatric hospital.

STUDY POPULATION

Patients with large-angle infantile esotropia.

INTERVENTION

Treatment with botulinum toxin-augmented bilateral medial rectus muscle recessions ("augmented-surgery group") or traditional bilateral medial rectus muscle recessions ("surgery-only group").

MAIN OUTCOME MEASURE

The effect of surgery on ocular alignment at 4 months, measured in prism diopters of change per mm of surgery (PD/mm).

RESULTS

There were 14 patients in the augmented-surgery group and 16 patients in the surgery-only group. The mean effect on alignment was significantly greater in the augmented-surgery group compared to the surgery-only group at 4 months (5.7 ± 1.3 vs 4.0 ± 1.4 PD/mm, P = .002) and at 1 year (5.4 ± 1.2 vs 3.7 ± 1.2 PD/mm, P = .002). There was a partial loss of treatment effect between 4 months and 1 year in both groups, which was similar in magnitude (P = .57). On linear regression, there was a trend toward a positive correlation between botulinum toxin dose and treatment effect, but this was not statistically significant (P = .09).

CONCLUSIONS

Botulinum toxin augments the surgical effect of medial rectus muscle recession. Botulinum toxin-augmented surgery may be an alternative to traditional options for large-angle infantile esotropia. A surgical dosing table is proposed for this technique.

Peribulbar and Retrobulbar Combined Anesthesia for Vitreoretinal Surgery using Ropivacaine

PURPOSE

To evaluate the efficacy and clinical effects of local retrobulbar anesthesia using ropivacaine in vitreoretinal surgery.

METHODS

Prospective study. A total of 919 vitreoretinal operations were followed. The operations were divided into three groups, depending on the degree of anesthesia needed. Group A: Vitrectomies with episcleral procedures (208 vitrectomies for detached retina or perforating trauma). Group B: Episcleral procedures only (410 operations for detached retina without vitrectomy). Group C: Vitrectomies without episcleral surgery (301 operations for macular pucker or hole, proliferative diabetic retinopathy, or silicone oil removal). Anesthesia was administered using a 23-gauge Atkinson-type retrobulbar needle, after topical anesthesia. Six mL of the solution containing 7.5 mg ropivacaine/mL were injected into the peribulbar space, and the other 4 mL deeper, into the retrobulbar space. The degree of infiltration of the palpebral region, the motor block in the extrinsic ocular muscles, and pain felt were checked and rated.

RESULTS

Swelling of lids was seen in 885 patients (96%); in 21 (2%) swelling was partial. In 13 patients (1%) there were no signs of infiltration. The motor block was total in 801 (87%) eyes, while 118 (12%) had reduced ocular movements. The degree of anesthesia was as follows, considering the three groups together: no pain = 855 (93%) patients; moderate pain = 44 (4%) patients; very strong pain = 20 (2%) patients. No adverse events or side effects were observed.

CONCLUSIONS

Ropivacaine used for retrobulbar-peribulbar combined anesthesia in vitreoretinal surgery showed excellent clinical efficacy as regards analgesia and muscle akinesia.

Effects of retinoic acid signaling on extraocular muscle myogenic precursor cells in vitro

One major difference between limb and extraocular muscles (EOM) is the presence of an enriched population of Pitx2-positive myogenic precursor cells in EOM compared to limb muscle. We hypothesize that retinoic acid regulates Pitx2 expression in EOM myogenic precursor cells and that its effects would differ in leg muscle. The two muscle groups expressed differential retinoic acid receptor (RAR) and retinoid X receptor (RXR) levels. RXR co-localized with the Pitx2-positive cells but not with those expressing Pax7. EOM-derived and LEG-derived EECD34 cells were treated with vehicle, retinoic acid, the RXR agonist bexarotene, the RAR inverse agonist BMS493, or the RXR antagonist UVI 3003. In vitro, fewer EOM-derived EECD34 cells expressed desmin and fused, while more LEG-derived cells expressed desmin and fused when treated with retinoic acid compared to vehicle. Both EOM and LEG-derived EECD34 cells exposed to retinoic acid showed a higher percentage of cells expressing Pitx2 compared to vehicle, supporting the hypothesis that retinoic acid plays a role in maintaining Pitx2 expression. We hypothesize that retinoic acid signaling aids in the maintenance of large numbers of undifferentiated myogenic precursor cells in the EOM, which would be required to maintain EOM normalcy throughout a lifetime of myonuclear turnover.

Ptosis induced by topical steroid eye drops: Two cases reports

RATIONALE

Ptosis is a rare complication of periocular steroid use. Studies report that local injections of steroids produce ptosis. We describe the first 2 cases of ptosis because of long-term treatment with topical steroid eye drops.

PATIENT CONCERNS

Two cases admitted to our hospital because of ptosis of their right eye after long-term treatment with topical steroid eye drops. Both of them had uncontrolled Posner-Schlossman syndrome.

DIAGNOSIS

Two cases were diagnosed as steroid-related ptosis.

INTERVENTIONS

Regulatory anti-inflammation therapy was prescribed for case 1, and after inflammation control, phacoemulsification was done for her. Six months after steroid withdrawal, the levator resection of the right eye was performed. Case 2 refused our advice of steroid reduction and ptosis surgery.

OUTCOMES

After surgery, case 1 retained a symmetrical appearance during a 1-year follow-up. In the surgery, we found thin levator muscles and slack levator palpebrae superioris aponeurosis (LPSA) in the affected eye. Postoperative transmission electron microscopy revealed typical signs of apoptosis in levator muscle cells.

LESSONS

We suggest topical application of steroids induces levator muscle apoptosis and LPSA weakness, and results in ptosis.

Comparison of Botulinum Toxin With Surgery for the Treatment of Acute-Onset Comitant Esotropia in Children

PURPOSE

To determine whether botulinum toxin is as effective as strabismus surgery in the treatment of acute-onset comitant esotropia in children.

DESIGN

Retrospective, nonrandomized, comparative clinical study.

METHODS

Setting: Tertiary care pediatric hospital.

STUDY POPULATION

Forty-nine children with acute-onset comitant esotropia.

INTERVENTION

Treatment with either botulinum toxin ("chemodenervation group") or standard incisional strabismus surgery ("surgery group").

MAIN OUTCOME MEASURE

Success rate at 6 months (total horizontal deviation of 10 prism diopters or less and evidence of binocular single vision).

RESULTS

There were 16 patients in the chemodenervation group and 33 patients in the surgery group. The success rate was not significantly different at 6 months (81% vs 61%, P = .20) or at 18 months (67% vs 58%, P = .74). The median angle of deviation and median stereoacuity were not significantly different at 6 or 18 months. The chemodenervation procedure was not inferior to incisional strabismus surgery at 6 months. The duration of general anesthesia (5 vs 71 min, P < .001) and time in the post-anesthesia care unit (37 vs 93 min, P < .001) were significantly shorter in the chemodenervation group. Botulinum toxin injection payment averaged $874 per procedure compared with $2783 for strabismus surgery.

CONCLUSIONS

Botulinum toxin is at least as effective as surgery in the treatment of acute-onset comitant esotropia at 6 months while reducing the duration of general anesthesia and healthcare costs.

Subacute sarcoid myositis with ocular muscle involvement; a case report and review of the literature

Sarcoidosis is a chronic granulomatous disease that can affect multiple organs. The lungs, eyes, and skin are known to be highly affected organs in sarcoidosis. There have been reports based on random muscle biopsy that 32-80% of systemic sarcoidosis comprises noncaseating granulomas; however, muscle involvement in sarcoidosis is generally asymptomatic and has an unknown frequency. We describe a case of acute to subacute sarcoid myositis of the skeletal and extraocular muscles. Typical ophthalmic involvement (manifested by infiltration of the ocular adnexa, intraocular inflammation, or infiltration of the retrobulbar visual pathways) and extraocular sarcoid myositis (as with the present case) is infrequently reported. It is important to keep in mind the rare yet perhaps underestimated entity of sarcoid myositis, and to utilize muscle biopsy and imaging tests for appropriate diagnosis and management of patients with sarcoidosis.

Isolated extraocular orbital mass: a rare presentation of sarcoidosis

We report a case of orbital sarcoidosis in a 66 year old male who presented with one month history of right eye swelling and intermittent diplopia. MRI revealed an enhancing infiltrative soft tissue mass in the inferior aspect of the right orbit and biopsy of the mass demonstrated non-necrotizing granulomas. Chest CT scan was normal and PET scan showed no other organ involvement. He was treated with tapering doses of prednisone over six months. Although relapse occurred while tapering prednisone to 20 mg per day, he responded well to the addition of azathioprine with complete resolution of visual difficulties and orbital the mass on repeat MRI. Sarcoidosis, presenting as an isolated orbital mass is rare, can be successfully treated and should be included in differential diagnosis.

Prolongation of Relaxation Time in Extraocular Muscles With Brain Derived Neurotrophic Factor in Adult Rabbit

PURPOSE

We tested the hypothesis that short-term treatment with brain derived neurotrophic factor (BDNF) would alter the contractile characteristics of rabbit extraocular muscle (EOM).

METHODS

One week after injections of BDNF in adult rabbit superior rectus muscles, twitch properties were determined in treated and control muscles in vitro. Muscles were also examined for changes in mean cross-sectional areas, neuromuscular junction size, and percent of myofibers expressing specific myosin heavy chain isoforms, and sarcoendoplasmic reticulum calcium ATPases (SERCA) 1 and 2.

RESULTS

Brain derived neurotrophic factor-treated muscles had prolonged relaxation times compared with control muscles. Time to 50% relaxation, time to 100% relaxation, and maximum rate of relaxation were increased by 24%, 27%, and 25%, respectively. No significant differences were seen in time to peak force, twitch force, or maximum rate of contraction. Brain derived neurotrophic factor treatment significantly increased mean cross-sectional areas of slow twitch and tonic myofibers, with increased areas ranging from 54% to 146%. Brain derived neurotrophic factor also resulted in an increased percentage of slow twitch myofibers in the orbital layers, ranging from 54% to 77%, and slow-tonic myofibers, ranging from 44% to 62%. No significant changes were seen SERCA1 or 2 expression or in neuromuscular junction size.

CONCLUSIONS

Short-term treatment with BDNF significantly prolonged the duration and rate of relaxation time and increased expression of both slow-twitch and slow-tonic myosin-expressing myofibers without changes in neuromuscular junctions or SERCA expression. The changes induced by BDNF treatment might have potential therapeutic value in dampening/reducing uncontrolled eye oscillations in nystagmus.

Botulinum toxin injection for restrictive myopathy of thyroid-associated orbitopathy: success rate and predictive factors

PURPOSE

To evaluate the rate of and predictive factors for successful treatment of restrictive myopathy in thyroid-associated orbitopathy (TAO) using botulinum toxin injection.

METHODS

Twenty patients with restrictive myopathy of TAO were enrolled in the study. Abnormal thyroid function test results were not a prerequisite for inclusion. In each extraocular muscle 25 units of botulinum toxinA were injected. The success rate, calculated at 2 years or last follow-up before surgery, was defined as proportion of the cases with esotropia of <10(Δ), vertical deviation of <5(Δ), and no diplopia in primary position and downgaze for at least 1 year. Both univariate analysis and multivariate logistic regressions were performed to identify the factors associated with success.

RESULTS

The procedure was successful in 11 cases (55%): in 8 patients with predominantly esotropia, 1 patient with predominantly hypotropia, and 2 patients of mixed type. Four factors were significantly associated with the success: type of deviation (P = 0.007), lower amounts of hypotropia (P = 0.001) and esotropia (P = 0.05), and lower degree of extorsion (P = 0.01). In the multivariate logistic regression, only lower amount of hypotropia was significantly associated with the success (P = 0.09, OR = 1.36).

CONCLUSIONS

Botulinum toxin injection can be an effective alternative for the treatment of the restrictive myopathy in TAO. The best candidates for injection of the toxin are patients with esotropia, smaller angle of horizontal and vertical deviations, and lower degree of extorsion.

Inferior Oblique Botulinum Toxin Injection: A Postoperative Diplopia Test for Secondary Inferior Oblique Muscle Overaction

PURPOSE

To evaluate the utility of botulinum toxin injection into the inferior oblique muscle for secondary inferior oblique muscle overaction.

METHODS

A retrospective review of 18 patients and 23 injections performed over a 9-year period. Indications and deviations in primary position and contralateral gaze before and after injection were recorded. Functional outcomes and further management (conservative vs surgical) were observed.

RESULTS

In 14 patients, chemodenervation resulted in a temporary improvement in symptoms. Eleven of these patients went on to have inferior oblique myectomy with resolution of their diplopia. Two patients preferred to receive regular injections of botulinum toxin as a treatment.

CONCLUSIONS

Botulinum toxin chemodenervation of the inferior oblique muscle in cases of secondary inferior oblique muscle overaction is useful where one needs to establish a risk of overcorrection following planned inferior oblique muscle weakening. This is particularly true in cases where the primary position deviation may be small but symptoms of diplopia exist on contralateral side gaze, giving rise to a narrowed field of binocular single vision.

Tonic pupil after botulinum toxin-A injection for treatment of esotropia in children

A total of 27 children with esotropia (mean age, 3.9 years; range, 9 months to 13.8 years) were enrolled in a 9-month observational study following botulinum toxin A (BTX-A) injection of one (n = 7) or both (n = 20) medial rectus muscles. BTX-A dosage ranged from 3.0 to 6.0 units per muscle. Three participants developed tonic pupil, noted at the first follow-up visit, occurring 12-19 days after injection. All 3 cases occurred in the left eye of participants who underwent bilateral BTX-A injection by the same surgeon. Anisocoria diminished from a maximum of 4 mm at the 2-week visit to 1-2 mm in all patients over the 9-month postinjection data collection period. No adverse visual outcomes were noted. Tonic pupil is an infrequently reported complication of BTX-A injection for strabismus. The experience of our investigator group suggests the need for careful injection technique and thorough preinjection counseling.

Quantitative Intraoperative Torsional Forced Duction Test

PURPOSE

We developed a method for quantifying intraoperative torsional forced ductions and validated the new test by comparing patients with oblique dysfunction and controls.

DESIGN

Comparative case series.

SUBJECTS

We studied 33 eyes with oblique dysfunction (9 with presumed congenital superior oblique palsy [SOP], 13 with acquired SOP, 7 with Brown syndrome, and 4 with inverted Brown syndrome) and 31 controls. We also studied 6 eyes after superior oblique (SO) disinsertion and 2 eyes after inferior oblique (IO) disinsertion.

METHODS

Under deep general anesthesia, the 12 and 6 o'clock positions at the limbus were marked and the globe was maximally excyclorotated and incyclorotated without retroplacement until the first resistance was felt, and the angle of rotation (in degrees) was read on a Mendez ring by the surgeon. A photograph was taken in each position to be read by a masked observer.

MAIN OUTCOME MEASURES

Maximal excyclorotation and maximal incyclorotation in each oblique dysfunction and in controls by both surgeon's report and photographic assessment. We duplicated the photographs to evaluate test-retest reliability and to evaluate agreement between the surgeon's assessments and the photographic assessment.

RESULTS

Surgeon's assessment revealed greater maximal excyclorotation in eyes with presumed congenital SOP than in controls (median, 40 vs. 30 degrees). Maximal excyclorotation in eyes with acquired SOP was similar to that in controls (30 degrees in both). Eyes with Brown syndrome and inverted Brown syndrome had lower maximal excyclorotation than in controls (10 and 20 vs. 30 degrees, respectively). Maximal incyclorotation in eyes with inverted Brown syndrome was lower than in controls (12.5 vs. 30 degrees), whereas it was similar to that of controls in eyes with presumed congenital SOP, acquired SOP, and Brown syndrome (30 degrees in each condition). Median maximal excyclorotation after SO disinsertion was 62.5 degrees, and maximal incyclorotation after IO disinsertion was 60 degrees. Photographic assessment yielded findings essentially identical to the surgeon's report. Test-retest reliability of the photographic reading was excellent, and agreement between the surgeon's report and the photographic reading was also excellent (95% limits of agreement, 4.4 and 11.6; intraclass correlation coefficient, 0.97 and 0.82, respectively).

CONCLUSIONS

The new torsional forced duction test enables quantitative assessment of SO and IO tightness and laxity.

The role of tissue resection length in the determination of post-operative eyelid position for Muller's muscle-conjunctival resection surgery

PURPOSE

To investigate the relationships between pre-operative marginal reflex distance (MRD), tissue resection length, phenylephrine response, and change in MRD with surgery for a cohort of individuals undergoing Muller's muscle conjunctival resection (MMCR) surgery.

METHODS

All cases of MMCR surgery performed over a 13-year period at a single institution were screened for entry. Individuals with adequate photographic documentation and follow up were included. Patients with previous or concurrent upper eyelid, orbital or eyebrow disease of surgery were excluded. Marginal reflex distance (MRD) was calculated based on photographs utilizing public domain software. Data was plotted for inspection and appropriate statistical tests were performed.

RESULTS

During the study period 198 eyes fit criteria for analysis. A loose association between tissue resection length and change in MRD with surgery was found (r = 0.176, p < 0.05); this relationship was not significant in ANOVA analysis (p = 0.367). There was a strong association between MRD change with surgery and pre-operative MRD (r = 0.498, p < 0.01). Approximately 28% of the sample responded to 2.5% phenylephrine drop instillation with a greater than 2 mm increase in MRD. The response to phenylephrine was strongly associated with pre-operative MRD (r = -0.441, p < 0.01). A regression on change in MRD with surgery with tissue resection, phenylephrine response >2 mm and pre-operative MRD as variables revealed a model with pre-operative MRD as the only significant predictor (p < 0.01).

CONCLUSION

Tissue resection length and phenylephrine response play small roles relative to pre-operative MRD in the determination of change in MRD with MMCR surgery.

[Comparative evaluation of efficacy of the upper part of the face endoscopic lifting in dynamics of postoperative period]

Comparative estimation of results for endoscopic lifting of the face upper part in dynamics of early and late postoperative period was adduced. In accordance to results of analysis, concerning the eyebrows height in a control terms, there was established, that through one year postoperatively the eyebrows have a tendency towards ptosis due to activity of the eyes circular muscles. Deterioration of the result achieved post-operatively is less prominent in patients after preliminary chemical denervation of mimic muscles. Chemical denervation of the eyes circular muscles, using injections of botulinic toxine type A before 2 weeks preoperatively secures a stable fixation of tissues in early postoperative period, what permits to escape loss of the result achieved, secures the results improvement in late postoperative period in 3.7 times.

Transient sixth cranial nerve palsy following orgasm abrogated by treatment with sympathomimetic amines

PURPOSE

To describe a unique disorder where a transient 6th nerve palsy leading to diploplia following orgasm developed in a 28-year-old woman. This coincided with a weight gain of 100 pounds in a short time without a corresponding change in dietary habits.

MATERIALS AND METHODS

She was treated with the sympathomimetic amine dextroamphetamine sulfate.

RESULTS

Indeed she immediately responded to treatment with dextroamphetamine sulfate sustained release capsules with complete resolution of the episodes of 6th nerve palsy following orgasm.

CONCLUSIONS

The main importance of this case is that it suggests that orgasm causes a transient generalized decrease in sympathetic nervous system activity and that the achievement of an orgasm may require an increase in the sympathetic nervous system activity.

Botulinum toxin treatment in glaucomatous patients: a pilot study

PURPOSE

The purpose was to evaluate the efficacy of the treatment of iatrogenic entropion (IE), in patients affected by primary open angle glaucoma (POAG), by botulinum toxin injections (BTI).

PATIENTS AND METHODS

20 patients of the "Glaucoma Center" of the Hospital "Umberto I" (Rome) were examined. These patients had POAG and used prostaglandin analogues (PA). Mean age was 75.5 years old (range 68-83); they had been suffering from PAOG since 10 years and were not affected by other relevant systemic diseases. One to three BTI were made into the lower orbicularis muscle using a 0.3 G needle (0.025 to 0.05 units for each injection site).

RESULTS

The results were particularly significant in 18 out of 20 patients. Two patients showed slight improvements. A rating scale ranging from 0 to 6 points (0 corresponded to 'no effect' and 6 to the 'complete' resolution of the entropion) was used to evaluate the goals of the treatment. The average rating was 5.37 points.

CONCLUSIONS

The entropion due to glaucoma therapy with PA can be successfully treated with BTI in the orbicularis muscle, despite offering temporary therapeutic effects.

Short-term response of mitomycin C on the human rectus muscle following strabismus surgery: histological, ultrastructural, and biomechanical evaluation

This study investigated the inflammatory effect of intraoperative mitomycin C (MMC) on adhesion reformation in human rectus muscles. Ten consecutive patients who underwent medial rectus resection had their postoperative rectus muscles divided into two groups: control group (n = 10) and MMC group (n = 10). In the MMC group, the muscle was soaked for 2 min with MMC, prepared as a 0.2 mg/mL (0.02%) solution. The 0.02% MMC reactions were examined using histological analysis with hematoxylin-eosin (inflammatory response) and Masson's trichrome (collagen fibrils), immunoreactivities of cyclooxygenase-II (inflammatory response), and collagen type I and III, scanning electron microscopy analysis to quantify the diameter and D-periodicity of collagen fibrils, and atomic force microscopy analysis to quantify the diameter, D-periodicity, and adhesion force of collagen fibrils. The rectus muscles treated with 0.02% MMC showed a significantly increased inflammatory response (p < 0.05), increased collagen density (p < 0.0001), increased fibril diameter (p < 0.001 or p < 0.05), and decreased fibril adhesion force (p < 0.005) compared to the rectus muscles in the control group. MMC simultaneously caused an inflammatory response as well as nanostructural and biomechanical property changes in the collagen fibril network.

Botulinum toxin injection as primary treatment for esotropia in patients with cerebral palsy

PURPOSE

Botulinum toxin type A is a potent neurotoxin that blocks the release of acetylocholine at the neuromuscular junction of cholinergic nerves. Cerebral palsy is cause of ocular disorders. There is an increased presence of strabismus, refractive errors, and reduced visual acuity. The purpose of this study was to assess the efficacy of botulinum toxin injection in the treatment of esotropia in patients with cerebral palsy.

MATERIAL AND METHODS

Seven patients were included in the study. All patients had a full ophthalmic examination on initial visit, including cycloplegic refraction and duction. The angle of esotropic deviation at distance was recorded in prism diopters. The botulinum toxin type A was administered into the medial rectus muscle under general anesthesia.

RESULTS

Mean age of the patients was 12 years. The mean angle of deviation pretreatment was 36.6 PD. Successful motor alignment (orthotropia +/- 10 PD) was achieved in the botulinum toxin type A group in 57.1% of patients.

CONCLUSIONS

The use of botulinum toxin in the treatment of esotropia in children and adolescents with cerebral palsy is an alternative to conventional surgical therapy.

Effects of sequential injections of hepatocyte growth factor and insulin-like growth factor-I on adult rabbit extraocular muscle

PURPOSE

To determine whether hepatocyte growth factor (HGF) and insulin-like growth factor-I (IGF-I) have synergistic effects in promoting extraocular muscle fiber growth and force generation.

METHODS

A superior rectus muscle of adult rabbits was treated with either a single injection of HGF or sequential injections of HGF followed 1 week later by IGF-I. One week after HGF alone and 1 week after the IGF-I injection, the superior rectus muscles from treated and control orbits were examined for alterations in force generation as well as changes in myofiber size.

RESULTS

Injection of HGF alone did not result in changes to muscle force, specific tension, or myofiber cross-sectional area; however, it did result in a significant increase in numbers of satellite cells. Sequential injection of HGF and IGF-I resulted in significantly increased force, specific tension, and myofiber cross-sectional areas as well as increased numbers of satellite cells.

CONCLUSIONS

Preinjection with HGF augments the treatment effect of IGF-I. This synergistic effect is likely a result of HGF-induced activation of satellite cells and should allow a reduction in IGF-I dosing required to produce a given increase in extraocular muscle force generation.

Long-term follow-up of bilateral botulinum toxin injections versus bilateral recessions of the medial rectus muscles for treatment of infantile esotropia

PURPOSE

To compare long-term outcomes of botulinum toxin A injection with incisional surgery for the management of infantile esotropia.

SUBJECTS AND METHODS

Medical records of infants <24 months treated for esotropia with either botulinum toxin injection (botulinum group) or bilateral medial rectus muscle recessions (surgery group) were reviewed. Minimum follow-up was 48 months, and patients with accommodative esotropia or inferior oblique muscle overaction were excluded. Success was defined as alignment with 10(Δ) of orthophoria without surgery (botulinum group) or without reoperation (surgery group) and compared by the use of an adjusted odds ratio (aOR).

RESULTS

The record review identified a total of 51 patients, with 25 in the botulinum group and 26 in the surgery group. Median pretreatment deviation was similar in the botulinum and surgery groups (40(Δ) vs 45(Δ); P = 0.37), but median age at treatment was earlier in the botulinum group (10 vs 12.5 months; P = 0.01). The mean number of injections in successfully treated botulinum group patients was 1.4. The success rate was similar in the botulinum (68%) and surgery (77%) groups (aOR = 0.87, P = 0.87). The median follow-up time was longer in the botulinum group (84 vs 75 months; P = 0.02). Gross stereopsis was demonstrable in 10 of 15 patients in the botulinum group and 9 of 13 in the surgery group (aOR = 3.6, P = 0.46).

CONCLUSIONS

There was no difference in binocular alignment with botulinum toxin versus surgical treatment. Botulinum toxin injection may be considered a primary treatment for infantile esotropia.

Repeated triamcinolone acetonide injection in the treatment of upper-lid retraction in patients with thyroid-associated ophthalmopathy

OBJECTIVE

To evaluate the efficacy and safety of repeated subconjunctival injections of triamcinolone in the treatment of upper-lid retraction with thyroid-associated ophthalmopathy.

DESIGN

Interventional controlled retrospective clinical study.

PARTICIPANTS

We studied 23 eyes in 15 patients as the nontreatment control group and 35 eyes in 21 patients as the treatment group.

METHODS

In the treatment group, triamcinolone acetonide was subconjunctivally injected into each lid as 4 doses of 20 mg at 1-month intervals. After the treatment, the eyes were divided into 2 groups, response and nonresponse, based on the improvement in margin reflex distance. The eyes of the nontreatment group received no medicine. The eyes were examined regularly.

RESULTS

The rate of spontaneous improvement in the nontreatment group was 17.4%. The mean rate of effectiveness was 68.6%. The improvement of upper-lid retraction was 2.31 mm (0 to 7 mm). The margin reflex distance was significantly smaller at 1 month after the initiation of treatment. Mean lid retraction time before treatment was 4.58 months in the response group versus 9.91 months in the nonresponse group. In the eyes presenting upper-lid retraction up to 6 months before treatment was initiated, the response rate was 83.3%. The response rate was only 36.4% when lid retraction developed more than 6 months before the procedure. The muscle thickness of the levator/superior rectus complex was significantly reduced after treatment in the response group (5.13 ± 0.85 mm at last follow-up vs. 5.69 ± 0.93 mm at baseline).

CONCLUSIONS

Repeated subconjunctival injection of triamcinolone is an effective and safe treatment for upper-lid retraction due to thyroid-associated ophthalmopathy.

Bupivacaine injection myotoxicity on extraocular muslces. A strabismus alternative treatment: extended histological changes induced in a rabbit model

PURPOSE

To evaluate longer term histological changes of extraocular muscles induced by bupivacaine toxicity.

METHODS

The superior rectus and inferior rectus of white rabbits were injected with 0.4 mg of agent in 0.3 ml of bupivacaine., Then, histological changes of these rectus muscles were examined at 1,2,4 and 8 weeks after injection.

RESULTS

Bupivacaine injection induced myotoxic changes in both orbital and global layers. Regenerating myofibers were found at 1 week after injection. These changes were reduced by 4 weeks post injection. At 4 weeks increasing muscle fiber size in both orbital and global layer were seen. There was no scar formation after 8 weeks post injection.

CONCLUSIONS

Extraocular muscle bupivacaine injection can cause acute myonecrosis followed with regeneration. After 8 weeks the muscles recovered with arranged myofibers almost at normal level. However we found increased myofiber diameter at 4 weeks after injection which was remained stable until 8 weeks post injection, Further investigation about functional change in these muscles is needed to facilitate application of this methodology.

Childhood myasthenia gravis: clinical features and outcomes

OBJECTIVE

To study the clinical features, treatment, outcome and factors that affected the outcome of myasthenia gravis (MG) in children.

MATERIAL AND METHOD

Children aged 16 years or less with diagnosed myasthenia gravis (MG) seen at Queen Sirikit National Institute of Child Health over a 15-year period with a minimum follow-up of 6 months were reviewed. Demographic, clinical characteristics, treatment and the outcome were analyzed.

RESULTS

One hundred and nineteen MG patients, 100 patients (84%) were ocular MG (OMG) and 19 patients (16%) were generalized MG (GMG). Median age of onset was 4.1 years. OMG patients had the age of onset earlier than GMG patients (p = 0.01). Female to male ratio was 1.8: 1. Ptosis was a clinical feature in 99%, accompanied with ophthalmoplegia in 63%, diplopia in 19.3%, extremity weakness in 13.4%, respiratory muscle weakness in 9%, head tilt in 10.1%, dysphagia in 7.5%, hyperthyroidism in 3.4% and epilepsy in 2.5%. One hundred and six patients who had ptosis as the initial symptom 67% were bilateral ptosis, 33% were unilateral ptosis, 10 patients progressed to GMG in 2 years. Almost all patients were treated with pyridostigmine and prednisolone. At the end of follow-up, 60.5% had pharmacological remission for more than 3 months, 18.5% had complete remission without medication. No definite factors associated with the remission were identified.

CONCLUSION

OMG is the majority of MG patients and the age of onset is earlier than GMG. Early treatment by prednisolone may have the favorable effect on OMG in the progression to GMG and subsequent involvement to the other eye.

Treatment of congenital esotropia with botulinum toxin type A

PURPOSE

To examine the effect of botulinum toxin type A injections given transconjunctivally into the medial recti muscles in patients with congenital esotropia.

METHODS

Eighty-two patients with congenital esotropia were treated with botulinum toxin type A transconjunctival injections into the medial recti muscles.

RESULTS

A Kaplan--Meier curve shows a 24-month success rate of 87% (n = 53) with alignment within 20 prism dioptres (PD) of the 80 patients who were seen at least 1 year following the last injection. Seven of the 80 patients underwent standard monocular surgery with recession of the medial rectus and resection of the lateral rectus muscle. Two patients were lost during follow-up.

CONCLUSION

Botulinum toxin type A injections into the medial recti muscles are a valuable alternative to conventional strabismus surgery.

Succinylcholine activation of human horizontal eye muscles

PURPOSE

Succinylcholine (Sch) can induce contracture in slow, multiply innervated muscle fibres of the extraocular muscles in animals of different species. Slow muscle fibres also exist in human eye muscle but their physiological properties have not been studied.

METHODS

Isometric tension development was recorded in the lateral and medial rectus muscles in 12 patients operated under general anaesthesia. A strain gauge probe was attached with 5-0 silk sutures to the muscle tendon. Recordings were made in 12 eye muscles with the tendon attached to the globe and in four muscles detached from the globe. Muscle activation was produced by i.v. injection of Sch at a dose of 0.2-0.3 mg/kg bodyweight.

RESULTS

  A single injection of Sch induced slow contractures lasting for several minutes. In the muscles attached to the globe, mean maximal isometric tension was 12.2 g in the lateral rectus and 12.8 g in the medial rectus. Similar tension was shown in the muscles detached from the globe.

CONCLUSIONS

The contracture of eye muscles in response to Sch showed characteristics typical of slow muscle fibre activation in amphibian and avian muscle and confirmed the participation of slow fibre systems in ocular motor control.

Visual and systemic outcomes in pediatric ocular myasthenia gravis

PURPOSE

To evaluate visual and systemic outcomes in pediatric patients with purely ocular myasthenia gravis (OMG) treated at the Children's Hospital of Philadelphia.

DESIGN

Retrospective chart review.

METHODS

Pediatric patients with OMG seen at a single institution over a 16-year period with a minimum follow-up of 1 year were reviewed. Associations of demographic and clinical characteristics with disease resolution, amblyopia, and development of generalized symptoms of myasthenia gravis were analyzed.

RESULTS

Thirty-nine patients were identified, with a mean age of 5.4 ± 4.8 years and mean follow-up of 4.8 ± 4.3 years. Fifteen patients were treated with pyridostigmine only, 19 (49%) also received steroids, and 15 (38%) underwent thymectomy. Four patients (10%) received steroid-sparing immunosuppressive therapy. Resolution occurred in 10 patients, and generalized symptoms eventually occurred in 9 patients. Although 10 patients were treated for amblyopia, only 1 had amblyopia at the final visit. There was no correlation between sex or age with amblyopia or development of generalized symptoms. Thymectomy, when performed before the onset of generalized symptoms, showed a trend toward protection from the development of generalized symptoms (P = .07).

CONCLUSIONS

In our series, 24% of patients had disease resolution and 23% had generalized symptoms. Our larger cohort confirms previous findings that treated and untreated pediatric patients with OMG have a relatively low risk of developing generalized symptoms and that related amblyopia is readily reversible. Although our treatments were more aggressive than those previously reported, our rates of amblyopia and development of generalized symptoms are comparable.

Treating strabismus by injecting the agonist muscle with bupivacaine and the antagonist with botulinum toxin

PURPOSE

We report the results of injection of bupivacaine (BUP) and botulinum toxin (BT) into agonist and antagonist muscles, respectively, to treat horizontal strabismus.

METHODS

We treated both horizontal muscles of 7 patients with comitant horizontal strabismus, 2 patients with partial lateral rectus (LR) paralysis, and one elderly myopic patient with acquired esotropia, injecting the agonist muscle with BUP in concentrations of 0.75% to 3.0% and volumes of 3.0 to 5.0 mL, and the antagonist with BT in about half the usual therapeutic dose to prevent it from stretching the BUP-treated muscle during its regeneration following BUP myotoxicity. We reinjected BT in one patient who had an inadequate response from the initial BT dose.

RESULTS

The 7 comitant patients were corrected (on average) 19.7 prism diopters (Delta), from 28.3Delta to 8.6Delta, at 193 days after injection. Muscle volume increase after BUP injection was 5.8% at 158 days. One LR palsy patient without LR atrophy was changed 55Delta; the other, with LR atrophy, was corrected 4Delta. Two patients had transient vertical deviations from the BT injection. The myopic patient with esotropia was unchanged.

CONCLUSIONS

Injections of BUP and BT corrected 7 patients with comitant horizontal strabismus an average of 19.7Delta, about double the correction reported from BUP injection alone. BUP-injected muscles increased size by 5.8%. Of 2 patients with LR weakness, one without LR atrophy was changed by 55Delta, but another with LR atrophy was corrected only 4Delta.

Acquired distance esotropia associated with myopia

BACKGROUND

Von Graefe (1864)(1) and Bielschowsky (1922)(2) described acquired progressive esotropia, with typically a larger angle for distance than near, associated with moderate myopia. This is unlike the esotropia seen in patients with high myopia.

METHODS

We reviewed our patient records, finding 26 cases: 14 were female, 12 male. Age range at first presentation was 37-74 with a mean of 55.5. The myopia was from -0.75 to -10.00, with a mean of -5.50 in each eye. Eighteen patients mostly wore glasses, eight mainly wore contact lenses. All complained of horizontal diplopia. Seventeen (65%) had been treated with prisms with a gradual increase in power.

RESULTS

Six patients (23%) continued with prisms although surgery has been offered in three cases. Seven patients (27%) had botulinum toxin to one medial rectus muscle. In two cases this proved to be successful maintenance therapy, the remaining five have gone on to have surgery. Seventeen (65%) have undergone surgery (mainly unilateral medial rectus recession and lateral rectus resection) with relief of diplopia and discarding of prisms. Three patients required further surgery for a recurrence after 10-12 years and another is using prisms for a recurrence after 11 years. One patient has suffered an early recurrence 6 months following surgery and is having his neurological work-up repeated.

CONCLUSION

This unusual sub-type of strabismus is a benign entity, which responds well to prism correction or surgery in cases who wish to wear contact lenses or whose prisms become inconveniently strong.

Does Botulinum toxin have a role in the treatment of small-angle esotropia?

A retrospective review of the Toxin Clinic database was carried out over an 18-year period. We identified 68 patients with esotropia of 20 prism dioptres and under who were treated with Botulinum toxin. There were 47 females and 21 males, with a mean age of 34 years (range 11-78 years). Thirty-two (47%) patients had residual esotropia, 20 (29%) had primary esotropia, 11 (16%) had consecutive esotropia, 4 (6%) had secondary esotropia and 1 (1.5%) had a decompensating esophoria. The mean pre-toxin angle was 16 prism dioptres (range 6-20). A total of 434 injections were given, with an average of 6 per patient (range 1-36). Forty-five (66%) patients underwent continued toxin treatment with an interval of 3 to 31 months. Thirteen (19%) patients achieved long-term benefit from only one injection. Seven were unable to demonstrate binocular vision pre-injection but demonstrated it post-injection. Following an initial injection, nine (13%) patients proceeded to surgery. Botulinum toxin was a successful treatment for these patients and was well tolerated, with no side effects. It appears to have a definite role in the treatment of small-angle esotropia.

Effects of intraoperative sponge mitomycin C and 5-fluorouracil on scar formation following strabismus surgery in rabbits

PURPOSE

To investigate the influence of 5-fluorouracil (5-FU) and mitomycin C (MMC) on the postoperative adhesions following strabismus surgery in rabbits.

METHODS

Twenty-one New Zealand white rabbits were used in this prospective, masked, controlled trial. Both eyes of 20 animals underwent 3-mm recession of the superior rectus muscle (SRM). In group I (io animals), one eye of each animal received topical application of MMC (0.2 mg/ml) for 5 minutes and the other eye (control eye) was treated with balanced salt solution (BSS) using an intraoperative sponge. In group II (10 animals), a randomly chosen eye of each animal was treated with 5-FU soaked sponges (50 mg/ml) for 5 minutes and the fellow eye (control eye) with BSS. Two eyes of a rabbit were included as unoperated controls. Four weeks after the surgery, conjunctival vascularity and postoperative adhesions between the SRM Tenon's capsule (TC) and SRM sclera (scl) were assessed. Additionally, eyes were enucleated and evaluated histopathologically for evidence of scarring, granuloma formation, and muscle tissue changes under a light microscope.

RESULTS

MMC-treated eyes had a higher rate of avascular conjunctiva compared to both controls and 5-FU-treated eyes. Mean adhesion scores, particularly between the SRM-scl, were lower in eyes treated with antiproliferative agents compared to controls. The difference was statistically significant in MMC-treated eyes for the adhesions between SRM-scl (p = 0.03). Histopathological examination revealed less scarring and granuloma formation in MMC- and 5-FU-treated eyes compared to their control eyes.

CONCLUSIONS

MMC, and to a lesser extent 5-FU, are shown to be effective in reducing postoperative scarring following strabismus surgery in rabbits. It seems reasonable to suggest that antimetabolites should be used for cases having an increased risk of postoperative adhesions.

Acute effect of bupivacaine and ricin mAb 35 on extraocular muscle in the rabbit

PURPOSE

To identify acute histologic change of extraocular muscles induced by bupivacaine or ricin mAb 35 injection.

METHODS

The superior rectus and inferior rectus of white rabbits were injected with bupivacaine (0.4 mg in 0.3 ml) or ricin mAb 35 (0.2 microg/kg in 0.3 ml). After 1, 2, and 4 weeks, the rectus muscles were harvested, and postinjection changes in the muscle layers were examined histopathologically.

RESULTS

Bupivacaine and ricin mAb 35 induced myotoxic changes in both the orbital and the global layers. However, the inflammation and the myofiber destruction produced by bupivacaine injection was localized to the injection site, which compared with the diffuse change induced by ricin mAb 35. Inflammation reduced rapidly over 2 weeks. Regenerating myofibers with a central nucleus were found at 1 week after injecting these myotoxins. Four weeks after injection, the acute changes induced by these two toxins respectively were much recovered with prominent myofiber regeneration.

CONCLUSIONS

We found that extraocular muscle has a superb ability to recover from the acute injury induced by bupivacaine or ricin mAb 35, and the two myotoxins induce unique damage including the predilection of muscle layers and duration of damage persisted. Further investigation about the functional change during recovery from the myotoxin-induced injury of extraocular muscles is needed.

The relative abuse liability of oral oxycodone, hydrocodone and hydromorphone assessed in prescription opioid abusers

Abuse of prescription opioids has risen precipitously in the United States. Few controlled comparisons of the abuse liability of the most commonly abused opioids have been conducted. This outpatient study employed a double-blind, randomized, within-subject, placebo-controlled design to examine the relative abuse potential and potency of oral oxycodone (10, 20 and 40 mg), hydrocodone (15, 30 and 45 mg), hydromorphone (10, 17.5 and 25mg) and placebo. Healthy adult volunteers (n=9) with sporadic prescription opioid abuse participated in 11 experimental sessions (6.5h in duration) conducted in a hospital setting. All three opioids produced a typical mu opioid agonist profile of subjective (increased ratings of liking, good effects, high and opiate symptoms), observer-rated, and physiological effects (miosis, modest respiratory depression, exophoria and decrements in visual threshold discrimination) that were generally dose-related. Valid relative potency assays revealed that oxycodone was roughly equipotent to or slightly more potent than hydrocodone. Hydromorphone was only modestly more potent (less than two-fold) than either hydrocodone or oxycodone, which is inconsistent with prior estimates arising from analgesic studies. These data suggest that the abuse liability profile and relative potency of these three commonly used opioids do not differ substantially from one another and suggest that analgesic potencies may not accurately reflect relative differences in abuse liability of prescription opioids.