Anatomy and histology of the frontalis muscle.

PURPOSE: To determine the gross and histologic configurations of the medial and lateral frontalis muscle. METHODS: After making a midcoronal incision and bluntly dissecting to the orbital rim, the frontalis muscle was marked and measured. A protractor was used to measure the frontalis-orbicularis angle (FOA) and, when present, the angle of central bifurcation (AOB). Three strips of full-thickness forehead soft tissue measuring 0.5 cm × 8 cm were excised 3, 4.5, and 6 cm above the supraorbital notch and analyzed histologically for the presence of skeletal muscle fibers. Data were analyzed using 2-sample t tests, paired t tests, Pearson correlations, and mixed effect models. A p value of ≤ 0.05 was considered statistically significant. RESULTS: Sixty-four hemifaces of 32 cadavers (16 males) were dissected. All specimens were Caucasian. The average age was 78.2 years (range, 56-102 years). The average FOA was 88.7° (13.0°), and the average AOB was 90.0° (26.4°). A visible midline bifurcation occurred in 28 of 32 subjects (88%) at an average height of 4.7 cm (range, 2.4-7.2 cm) superior to the supraorbital notch. Continuous skeletal muscle fibers were present within the midline bifurcation histologically in 89%, 75%, and 11% of specimens 3.5, 5.0, and 6.5 cm above the supraorbital notch, respectively. In 46% of individuals, skeletal muscle fibers were continuously present microscopically within the gross bifurcation. CONCLUSION: While a medial frontalis muscle bifurcation occurs grossly in most senescent Caucasians, muscle fibers exist microscopically within this zone in nearly half of individuals.

Safety of onabotulinum toxin a injection to the central upper eyelid and eyebrow regions.

PURPOSE: To evaluate the safety of onabotulinum toxin A injected into the central upper eyelid and eyebrow regions. METHODS: The authors retrospectively reviewed the charts of all patients undergoing onabotulinum toxin A injection to the central upper eyelid and eyebrow between February, 2012, and November, 2012. Age, gender, indication, injection sites, number of central units, total number of units, and occurrence of adverse events were all recorded. RESULTS: A total of 300 procedures on 88 patients were performed, in whom the central upper eyelid and/or central eyebrow was injected with onabotulinum toxin A. There were 68 female and 20 male patients. Average age was 68.7±13.3 years (range, 42-92 years). Indications for central eyelid/eyebrow treatment included blepharospasm (34 patients, 176 procedures), hemifacial spasm (21 patients, 40 procedures), facial nerve disorders (2 patients, 9 procedures), and facial rhytides/eyebrow ptosis (31 patients, 75 procedures). The amount of neurotoxin injected into the central eyelid and eyebrow ranged from 2 to 12.5 units per encounter. Complications included diplopia (4% of total encounters), lagophthalmos (1% of total encounters), blepharoptosis (1% of total encounters), and blurry vision (1% of total encounters). Minor local effects, including bruising, bleeding, pain, and mild swelling, were recorded in 3.3% of total encounters. CONCLUSIONS: Placement of onabotulinum toxin A into the central upper eyelid and eyebrow is associated with a low rate of blepharoptosis. Central eyelid and eyebrow neurotoxin injection can be safely added to the regimen when treatment calls for chemodenervation of the central orbicularis oculi.

Dimensions and anatomic variations of the orbicularis oculi muscle in nonpreserved, fresh-frozen human cadavers.

PURPOSE: To determine average dimensions of the orbicularis oculi muscle (OOM) from the orbital rim and to investigate polymorphic variations through anatomical dissection of nonpreserved, fresh-frozen human cadavers. METHODS: The OOM was exposed using sharp and blunt dissection until its distal borders were identified. A metric ruler was used to measure the superior (S line), inferior (I line), and lateral (L line) dimensions of the OOM from the orbital rim. Data collection included age, gender, and race. Data were analyzed using 2-sample t tests, paired t tests, and mixed effect models. A p-value of ≤0.05 was considered statistically significant. RESULTS: A total of 40 hemifaces of 20 cadavers were dissected. All specimens were Caucasian. Ten specimens were men. Average age was 73.9 years (56-92 years). The overall S line was 1.4 cm (95% confidence interval [CI], 1.23-1.57), the I line was 1.2 cm (95% CI, 1.00-1.36), and the L line was 2.5 cm (95% CI, 2.27-2.68). Men had significantly larger average T, L, and S line values than women (p = 0.003, 0.005, 0.008, respectively). I lines did not differ significantly between genders (p = 0.28). CONCLUSIONS: In senescent Caucasians, the OOM extends approximately 1.4 cm superior, 1.2 cm inferior, and 2.5 cm lateral to the orbital rim. The muscle extends significantly further superiorly and laterally in Caucasian men than in women. Knowledge of the extent of the OOM should improve the understanding and the treatment of conditions affecting this region.

Intraoperative sub-tenon injection increases optic nerve length transection during enucleation.

PURPOSE: To determine the effect of sub-Tenon injection on the length of optic nerve resected during enucleation. METHODS: Case-control laboratory study on 22 orbits of 11 unpreserved, fresh-frozen human cadavers. Each cadaver underwent a conventional enucleation technique on one side and an otherwise identical technique on the contralateral side that included sub-Tenon injection of 2.5 ml normal saline in each oblique quadrant. Resected optic nerve lengths were measured and compared using Student t tests. RESULTS: The mean optic nerve length was 15.2 mm (range, 5.0-21.0 mm) in the sub-Tenon injection group and 11.3 mm (range, 5.0-19.0 mm) in control group (p = 0.015). CONCLUSIONS: Sub-Tenon injection during enucleation allows for significantly longer optic nerve resection lengths in unpreserved, fresh-frozen human cadavers.

NK/T-cell lymphoma of the nasal cavity causing contralateral dacryoadenitis.

PURPOSE: To report a case of NK/T-cell lymphoma of the nasal cavity with contralateral lacrimal gland involvement. METHODS: Observational case report. RESULTS: A 39-year-old woman with a 5-month history of right fungal rhinosinusitis was referred to our hospital. A nasal mucosal biopsy performed before referral was consistent with Aspergillus sp. Despite surgical and parenteral antifungal treatment, the symptoms continued to deteriorate. On admission, the ophthalmic evaluation showed inflammation over the left lacrimal gland area. The fundus examination revealed bilateral subretinal infiltration. Computed tomography scans of the orbits and sinuses showed mucosal thickening of the right nasal mucosa and sinuses. There was heterogeneous enhancement and infiltration of the left lacrimal gland. Lacrimal gland biopsy and repeated biopsies of the nasal cavity and sinus tissue were performed. Immunohistopathology of the lacrimal glands and nasal mucosa showed extranodal nasal-type NK/T-cell lymphoma. The patient was treated with cyclophosphamide, vincristine, adriamycin, prednisolone (3 cycles), and intrathecal methotrexate. The patient developed sepsis and died 2 months after initiation of chemotherapy. CONCLUSION: Dacryoadenitis can be a clinical manifestation of NK/T-cell lymphoma. To our knowledge, this is the first reported case of nasal NK/T-cell lymphoma with contralateral dacryoadenitis.

Mutation analysis of the VMD2 gene in thai families with best macular dystrophy.

BACKGROUND: To identify genetic mutations of the VMD2 gene in two Thai families with Best macular dystrophy. MATERIALS AND METHODS: Ophthalmic examination including best-corrected visual acuity (BCVA), dilated fundus examination and fundus photography, and electro-oculography (EOG) was performed in two probands and their family members. Mutation screening of the VMD2 gene was performed by single-strand conformation polymorphism (SSCP) analysis followed by direct DNA sequencing of the abnormal exons. RESULTS: The 58-year-old male proband demonstrated typical egg yolk-like macular lesion in both eyes. Mutational screening of VMD2 identified a band shift in exon 7, which was confirmed by direct DNA sequencing to be a G to A transition at position 724 bp. This novel missense mutation resulted in the change of an amino acid valine to methionine and was responsible for the abnormal Arden ratio in the proband's daughter. The second male proband age 25 had a characteristic egg yolk-like macular lesion in the left eye and a scrambled egg appearance in the right. Mutation analysis identified a C to T transition at position 652 bp in exon 6. This reported missense mutation led to an amino acid substitution of cysteine for arginine. The mutation was documented in the maternal grandmother, the mother, as well as the elder sister of the proband. CONCLUSIONS: The Val-242-Met mutation is associated with a late-onset visual disturbance and the Arg-218-Cys mutation was associated with marked intra-familial clinical variability of expression. Presymptomatic testing will be available to the family members at risk with high accuracy.