Regional Variations in Orbicularis Oculi Histology

Combination of Pretarsal and Preseptal Botulinum Toxin Injections in the Treatment of Blepharospasm: A Prospective Nonrandomized Clinical Trial

PURPOSE

To compare the efficacy of two botulinum toxin (BoNT) injection methods, pretarsal (PT) combined with preseptal (PS) injection (PT-PS) and conventional PT injection, in the treatment of benign essential blepharospasm (BEB).

DESIGN

Prospective nonrandomized clinical trial.

METHODS

From January 2023 to April 2024, 95 BoNT injections into orbicularis oculi were performed in 45 BEB patients, including 52 PT-PS injections s and 43 PT injections. Jankovic Rating Scale (JRS) and Blepharospasm Disability Index (BSDI) were used to assess motor symptoms. The efficacy of two injection methods for BEB was compared in terms of latency to response (LTR), latency to the peak response (LPR), duration of peak response (DPR), duration of response (DOR), satisfaction degree, and possible complications.

RESULTS

Both injection methods significantly improved JRS and BSDI scores in patients with BEB. However, PT-PS injections showed a shorter LTR ([4.00 (3.00, 6.00] vs 5.00 [4.00, 7.00] days, P = .024) and LPR (23.50 [16.00, 26.00] vs 26.00 [20.00, 30.00] days, P = .040), a longer DPR (88.00 [80.50, 104.75] vs 75.00 [65.00, 92.00] days, P = .003) and DOR (135.00 [118.50, 153.75] vs 121.00 [107.00, 135.00] days, P = .003) than PT injections. Patients with PT-PS injections were more satisfied than those with PT injections (9.50 [8.50, 10.00] vs 8.00 [7.50, 9.00], P < .001), and around 2/3 of patients were more willing to receive the combined injection method later. Among patients receiving PT-PS injections, only one case experienced ptosis, and there were no significant differences in other complications such as lacrimation, dry eyes, and blurred vision between the two injection methods.

CONCLUSIONS

PT-PS injections of BoNT showed more advantages in the treatment of BEB than PT injections in terms of both their efficacy and patients' satisfactions.

Damage to the orbicularis oculi muscle may impair the development of dermatochalasis

The purpose of this article is to investigate the changes that occur in the orbicularis oculi muscle (OOM) in patients with dermatochalasis. The OOM specimens from 26 patients were collected during upper eyelid blepharoplasty. Each specimen was divided into three parts, which were then examined using different techniques: formalin embedding for light microscopy, free freezing for histochemical examination, and fixation in 3% glutaraldehyde for electron microscopy. The severity of dermatochalasis was classified according to the anatomical landmarks. 78 specimens from patients with dermatochalasis were evaluated. Under light microscopy, specimens showed an increase in muscle fiber size variation, rounding of muscle fibers, and lobulation of myocytes in a fibrotic background. Under electron microscopy, loss of myofilaments, vacuolar vesicles, and swollen mitochondria were observed, along with osmophilic aggregates resembling nemadine bodies and collagen fibrils. A statistically significant association between the progression of dermatochalasis and the presence of aggregates resembling nemaline bodies was found (p- value < 0.005). Significant changes occur in the OOM in patients with dermatochalasis and the presence of aggregates resembling nemaline bodies is correlated with the degree of eyelid drooping. Thus, OOM may contribute in dermatochalasis progression.

Blood Supply of the Temporal Flap Pedicled With Orbicularis Oculi Muscle: Anatomy and Its Clinical Implications

BACKGROUND

Traumatic injury or tumor resection can lead to eyelid defects, nasal defects, and cheek defects. The temporal flap pedicled with orbicularis oculi muscle (OOM) can be used to repair these defects. This cadaver-based anatomic study aimed to evaluate the blood supply of this flap and investigate its clinical implications.

METHODS

Twenty hemifaces from 10 cadavers were used in this study. The number of arteries supplying OOM of the flap, the diameter of the artery entering OOM, and the maximum width of OOM were recorded. All data were presented as mean±SD values and analyzed using Student t-test. A P value<0.05 was considered statistically significant.

RESULTS

Of these 10 specimens, 7 were males and 3 were females. The average age was 67.7 years (range, 53-78 y). The number of arteries supplying OOM was 8.5±1.4 in the male and 7.8±1.2 in the female. The diameter of the zygomatico-orbital artery was detected as 0.53±0.06 mm in the male and 0.40±0.11 mm in the female. The maximum width of OOM was detected as 2.5±0.1 cm in the male and 2.2±0.1 cm in the female. Males had significantly larger average values than females in the diameter of zygomatico-orbital artery and maximum width of OOM (P=0.012, P<0.001, respectively). However, the number of arteries supplying OOM did not differ significantly between sex (P=0.322).

CONCLUSIONS

We conclude that the blood supply of the temporal flap pedicled with OOM is abundant and reliable. The findings provide surgeons with valuable anatomic knowledge for repairing facial defects with this flap.

Debunking the Puzzle of Eyelid Apraxia: The Muscle of Riolan Hypothesis

PURPOSE

Apraxia of eyelid opening (AEO) has been defined by the presence of an intermittent nonparalytic bilateral loss of the volitional ability to open the eyes or to maintain the eyelids in a sustained elevated position. It is not known whether the condition represents an apraxia, a dystonia, or a freezing phenomenon, and several different nomenclatorial terms have been suggested for this condition including the so-called AEO (scAEO), blepahrocolysis, focal eyelid dystonia, and so on. The primary goal of this review is to attempt to clarify the pathogenetic mechanisms underlying scAEO as a clinical phenomenon. This review also addresses the issue of whether scAEO is part of the spectrum of blepharospasm (BSP) which includes BSP, dystonic blinks and other dystonic eyelid conditions, or whether it is a separate phenomenologically heterogeneous disease with clinical features that merely overlap with BSP.

METHODS

A literature review was conducted in PubMed, MEDLINE, PubMed Central (PMC), NCBI Bookshelf, and Embase for several related keywords including the terms "apraxia of eyelid opening," "pretarsal blepharospasm," "blepharocolysis," "eyelid freezing," "eyelid akinesia," "levator inhibition," "blepharospasm-plus," as well as "blepharospasm." The clinical findings in patients with scAEO who fulfilled the classic diagnostic criteria of the disease that were originally set by Lepore and Duvoisin were included, while patients with isolated blepharospasm or dystonic blinks (DB) were excluded. In addition, electromyographic (EMG) studies in patients with scAEO were reviewed in detail with special emphasis on studies that performed synchronous EMG recordings both from the levator muscle (LPS) and the pretarsal orbicularis oculi muscle (OO).

RESULTS

The apraxia designation is clearly a misnomer. Although scAEO behaves clinically as a hypotonic freezing phenomenon, it also shares several cardinal features with focal dystonias. The authors broadly categorized the EMG data into 3 different patterns. The first pattern (n = 26/94 [27.6%]) was predominantly associated with involuntary discharges in the OO muscle and has been termed pretarsal blepharospasm (ptBSP). The commonest pattern was pattern no. 2 (n = 53/94 [56.38%]), which was characterized by involuntary discharges in the OO muscle, together with a disturbed reciprocal innervation of the antagonist levator muscle and is dubbed disturbed reciprocal innervation (DRI). This EMG pattern is difficult to discern from the first pattern. Pattern no. 3 (n = 15/94 [15.9%]) is characterized by an isolated levator palpebrae inhibition (ILPI). This levator silence was observed alone without EMG evidence of contractions in the pretarsal orbicularis or a disturbed reciprocal relation of both muscles.

CONCLUSION

EMG evidence shows that the great majority (84%) of patients show a dystonic pattern, whereas ILPI (16%) does not fit the dystonic spectrum. The authors propose that a spasmodic contraction of the muscle of Riolan may be the etiological basis for levator inhibition in patients with ILPI. If this is true, all the 3 EMG patterns observed in scAEO patients (ptBSP, DRI, and ILPI) would represent an atypical form of BSP. The authors suggest coining the terms Riolan muscle BSP ( rmBSP ) for ILPI, and the term atypical focal eyelid dystonia ( AFED ) instead of the term scAEO, as both terms holistically encompass both the clinical and EMG data and concur with the authors' theorem.

Preseptal and Pretarsal Botulinum Toxin Injection in Hemifacial Spasm and Blepharospasm: A 10-Year Comparative Study

Purpose

Preseptal and pretarsal botulinum toxin injections are approved for treatment of hemifacial spasm and blepharospasm. However, the long-term data is limited. We compared the efficacy, safety, and costs between preseptal and pretarsal injection in hemifacial spasm and blepharospasm.

Patients and Methods

The data were retrieved between 2011 and 2021. Consecutive hemifacial spasm and blepharospasm botulinum toxin patients were categorized as preseptal or pretarsal. Study outcomes were the difference in pre-and post-treatment modified Jankovic scale, self-reporting scales, time-related treatment, safety, and cost.

Results

Of 152 botulinum toxin-injected patients, 117 (77.0%) patients had hemifacial spasm and 35 (33.0%) patients had blepharospasm. Analysis included data pertinent to 1665 injections in hemifacial spasm (920 preseptal and 745 pretarsal) and 527 injections in blepharospasm (210 preseptal and 317 pretarsal). The difference between pre-and post-treatment modified Jankovic scale was lower in the preseptal group than in the pretarsal group in both hemifacial spasm and blepharospasm (1.5±0.8 vs 1.8±0.6, P-value <0.001 and 1.8±0.8 vs 3.1±0.9, P-value <0.001). There was no difference in duration of maximum response in hemifacial spasm between groups, while the blepharospasm with preseptal had a longer duration than blepharospasm with pretarsal. The preseptal injection was associated with more adverse events overall than the pretarsal (9.4% vs 5.2%, P-value <0.001). The total dose and cost per session in the preseptal group is lower for onabotulinum toxin but higher for abobotulinum toxin.

Conclusion

Pretarsal injections reduced symptom severity with fewer side effects. Further studies on the pharmacoeconomics of both techniques are required.

Complications of Preseptal Versus Pretarsal Botulinum Toxin Injection in Benign Essential Blepharospasm: A Randomized Controlled Trial

PURPOSE

The purpose of this study was to compare ocular complications and efficacy of preseptal (PST) versus those of pretarsal (PTS) botulinum toxin type A (BoNT-A) therapy in cases of benign essential blepharospasm (BEB).

DESIGN

Randomized clinical trial.

METHODS

Setting: university hospital.

PATIENTS

24 participants with BEB were enrolled from August 2019 to June 2020. All patients and the outcome evaluator were masked to the injection allocation.

INTERVENTIONS

for each participant, 1 eye was randomized to receive PST BoNT-A injection, and the fellow eye received PTS BoNT-A injection of the same amount from a single investigator. At baseline, 1, and 3 months after the injection, we collected the symptoms of tearing, lagophthalmos, ptosis, and diplopia and measured margin-to-reflex distance (MRD) 1 and 2 (mm), degree of lagophthalmos (mm), presence of ectropion, entropion, limitation of ocular motility, tear film breakup time (second), Schirmer's test (mm) , ocular surface staining scores (Oxford's scheme), and Jankovic rating scale of both eyes separately. Main outcome measurements were complications of the injection.

RESULTS

There were statistically significant higher rates of self-reported lagophthalmos in PTS (n = 12; 52.17%) than in PST (n = 7; 30.43%) BoNT-A injections (P = .024) and significantly higher estimated measurements of lagophthalmos in PTS (0.59 mm; 95% confidence interval [CI]: 0.44-0.72) than in PST (0.26 mm; 95% CI: 0.12-0.40) injection at 1 month using an interaction model (Bonferroni-corrected P = .001). No significant differences in the efficacy and other complication outcomes between the injection locations were observed.

CONCLUSIONS

PTS BoNT-A injection had a higher rate of lagophthalmos than PST BoNT-A injection for BEB.

High Therapeutic and Esthetic Properties of Extracellular Vesicles Produced from the Stem Cells and Their Spheroids Cultured from Ocular Surgery-Derived Waste Orbicularis Oculi Muscle Tissues

Extracellular vesicles (EVs) are paracrine factors that mediate stem cell therapeutics. We aimed at evaluating the possible therapeutic and esthetic applications of EVs prepared from the waste human facial tissue-derived orbicularis oculi muscle stem cells (OOM-SCs). OOM-SCs were isolated from the ocular tissues (from elders and youngsters) after upper eyelid blepharoplasty or epiblepharon surgeries. EVs were prepared from the OOM-SCs (OOM-SC-EVs) and their three-dimensional spheroids. OOM-SCs showed a spindle-like morphology with trilineage differentiation capacity, positive expression of CD105, CD 90, and CD73, and negative expression of CD45 and CD34, and their stem cell properties were compared with other adult mesenchymal stem cells. OOM-SC-EVs showed a high inhibitory effect on melanin synthesis in B16F10 cells by blocking tyrosinase activity. OOM-SC-EVs treatment led to a significant attenuation of senescence-associated changes, a decrease in reactive oxygen species generation, and an upregulation of antioxidant genes. We demonstrated the regeneration activity of OOM-SC-EVs in in vitro wound healing of normal human dermal fibroblasts and upregulation of anti-wrinkle-related genes and confirmed the therapeutic potential of OOM-SC-EVs in the healing of the in vivo wound model. Our study provides promising therapeutic and esthetic applications of OOM-SC-EVs, which can be obtained from the ocular surgery-derived waste human facial tissues.

Orbicularis Oculi Muscle Size and Function: Exploring the Influence of Aging and Exercise Training

The orbicularis oculi muscle is the sphincter muscle of the eyelids that blinks and closes the eyes. In this review, our aim was threefold: (1) to introduce the performance characteristics of blinking activity in young and older adults, (2) to discuss the influence of aging on the orbicularis oculi muscle in healthy adults, and (3) to provide information about the effect of facial exercise training on the orbicularis oculi muscle. To achieve the purpose of this review, a search using two electronic databases (PubMed and Scopus) and a search engine (Google Scholar) was conducted. The amplitude and peak velocity of spontaneously blinking behavior, which is an index of muscle function of the orbicularis oculi, appear to be affected by aging. The muscle thickness of the orbicularis oculi tends to be low in older adults, but there are issues that need to be examined further, such as differences in sex and measurement positions. There was no study on the effect of exercise training; however, the results of a highly trained man indicate that the orbicularis oculi muscles might elicit muscle hypertrophy through non-traditional resistance exercise.

Botulinum toxin for benign essential blepharospasm: A systematic review and an algorithmic approach

BACKGROUND

Currently, there is no standardised approach for benign essential blepharospasm treatment with botulinum toxin, and controversies still exist regarding this subject.

OBJECTIVE

The objective of this systematic review is to summarise and compare all the published data regarding benign essential blepharospasm treatment with botulinum toxin.

METHODS

On October 3, 2018, an online search of the Medline database was conducted. All articles with a detailed description of their botulinum toxin injection technique for benign essential blepharospasm were included in this review.

RESULTS

Five studies were selected for inclusion with a total of 854 patients. Four of the included studies used onabotulinumtoxin A and one study used abobotulinumtoxin A. All studies injected the pretarsal orbicularis occuli muscle. The preseptal orbicularis occuli was injected in four studies, and the preorbital muscle in three studies. The most commonly used method of evaluation was the Jankovic Rating Scale. Adverse events were transient, and dose related. Ptosis was more frequently encountered with the preseptal orbicularis injections.

CONCLUSION

Botulinum toxin injection for benign essential blepharospasm is a non-invasive and safe procedure. The pretarsal muscle should be considered as the key component when treating benign essential blepharospasm with botulinum toxin. We developed an algorithmic approach to the treatment of benign essential blepharospasm with botulinum toxin. However, further randomised controlled trials are warranted.

Identification and Characterization of Skeletal Muscle Stem Cells from Human Orbicularis Oculi Muscle

Skeletal muscle stem cell (SMSC) transplantation has shown great therapeutical potential in repairing muscle loss and dysfunction, but the muscle acquisition is usually a traumatic procedure causing pain and morbidity to the donor. In this study, we investigated the feasibility of isolating SMSCs from human orbicularis oculi muscle (OOM), which is routinely removed and discarded during ophthalmic cosmetic surgeries. OOM fragments were harvested from 18 female healthy donors undergoing upper eyelid plasties. Plastic-adherent cells were isolated from the muscles using a two-step plating method combined with collagenase digestion. A total of 15 cell cultures were successfully established from the muscle samples. These adherent cells were positive for the specific markers of SMSCs and could be directed toward the osteogenic, adipogenic, chondrogenic, and myogenic phenotypes in the presence of lineage-specific inductive media. Moreover, after cultured in the myogenic inductive medium for 3 weeks, the muscle cells were injected into the tibialis anterior muscles of nude mice and the cell fate was detected using a DiI-labeling technique. In vivo myogenesis was evidenced by the expression of DiI fluorescence after cell transplantation. The donor cells could be found in the satellite cell position and incorporated into the host myofibers. Our results demonstrated that human OOM represents a novel source of myogenic precursors with stem cell-like properties, which may provide a foundation for the SMSC-based therapeutics of skeletal muscle diseases.

In Vitro and In Vivo Osteogenesis of Human Orbicularis Oculi Muscle-Derived Stem Cells

BACKGROUND

Cell-based therapies for treating bone defects require a source of stem cells with osteogenic potential. There is evidence from pathologic ossification within muscles that human skeletal muscles contain osteogenic progenitor cells. However, muscle samples are usually acquired through a traumatic biopsy procedure which causes pain and morbidity to the donor. Herein, we identified a new alternative source of skeletal muscle stem cells (SMSCs) without conferring morbidity to donors.

METHODS

Adherent cells isolated from human orbicularis oculi muscle (OOM) fragments, which are currently discarded during ophthalmic cosmetic surgeries, were obtained using a two-step plating method. The cell growth kinetics, immunophenotype and capabilities of in vitro multilineage differentiation were evaluated respectively. Moreover, the osteogenically-induced cells were transduced with GFP gene, loaded onto the porous β-tricalcium phosphate (β-TCP) bioceramics, and transplanted into the subcutaneous site of athymic mice. Ectopic bone formation was assessed and the cell fate in vivo was detected.

RESULTS

OOM-derived cells were fibroblastic in shape, clonogenic in growth, and displayed phenotypic and behavioral characteristics similar to SMSCs. In particular, these cells could be induced into osteoblasts in vitro evidenced by the extracellular matrix calcification and enhanced alkaline phosphatase (ALP) activity and osteocalcin (OCN) production. New bone formation was found in the cell-loaded bioceramics 6 weeks after implantation. By using the GFP-labeling technique, these muscle cells were detected to participate in the process of ectopic osteogenesis in vivo.

CONCLUSION

Our data suggest that human OOM tissue is a valuable and noninvasive resource for osteoprogenitor cells to be used in bone repair and regeneration.