Clinical Relevance of the Variability of the Infraorbital Arterial Anatomy Evaluated by Three-Dimensional Computed Tomography.

BACKGROUND: Knowledge of the anatomy of the infraorbital artery (IOA) is crucial for the rejuvenation of the anterior medial aspect of the midface; however, studies adequately describing the anatomy of the IOA branches are lacking, and their connection with the ophthalmic artery branches remains unclear. OBJECTIVES: This study aims to elucidate the anatomical characteristics of the IOA in its deployment within the lower eyelid using three-dimensional (3D) technology, thereby offering an anatomical foundation for clinical surgical procedures. METHODS: An analysis was conducted on computed tomography scans of 132 cadaveric head sides post-contrast injection, utilizing the Mimics software for reconstruction. The study focused on examining the anastomosis of the IOA, its principal branches, and the branches emanating from the ophthalmic artery. RESULTS: The prevalence of type I IOA was observed at 38.6% (51/132), while Type II IOA was found in 61.4% (81/132) of cases. A 7.6% incidence (10/132) of IOA directly anastomosing with the angular artery was noted. The presence of palpebral branches (PIOA) was identified in 57.6% (76/132) of instances. In the lower eyelid, four distinct distribution patterns of IOA were discerned: The likelihood of Type I PIOA was 5.3%, whereas for Types IIA, IIB, and IIC PIOA, the probabilities were 8.3%, 32.6%, and 11.4%, respectively. The occurrence of the orbital branch of IOA was recorded at 41.7% (55/132). CONCLUSIONS: 3D technology can map IOA variants and identify the deployment patterns of IOA branches in the lower eyelid vascular vesicles at high resolution as a guide in clinical practice. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Evaluation of Supratrochlear, Supraorbital and Angular Artery Course Variations and Depth by Doppler Ultrasound.

BACKGROUND: Supratrochlear (STA), supraorbital (SOA), and dorsal nasal artery (DNA) branches from the ophthalmic artery and angular artery (AA) from the facial artery are the primary suppliers of blood to the upper face. Filler injection without precise knowledge of its vascular topography poses a risk of severe complications. METHODS: Seventy-four hemifaces from 37 subjects with a median age of 25.0 (21.0, 35.0) years and a median body mass index of 21.2 (20.0, 25.4) kg/m2 underwent high-frequency ultrasound tests between March 2022 and April 2022. The bilateral location, depth, peak systolic velocity (PSV), and inner diameter (ID) of the four periorbital arteries (STA, SOA, DNA, AA) were measured. RESULTS: The average ID ranges from 0.6~1.0 mm, and the average PSV ranges from 9.2~24.9 cm/s. All arteries detected passed through the superficial subcutaneous fascia. Most subjects' STAs traveled within 1.0 to 2.0 cm from the midline (left 96.8%, right 93.8%), while SOAs were mainly concentrated within 2.0 to 4.0 cm (left 83.9%, right 81.3%). STAs were more superficial and had a larger internal ID and PSV than SOAs (p<0.001). Except for the ID of the right SOA2 being significantly larger than that of the left SOA2 (p<0.05), no dominant side was found. The depth of STAs and SOAs was moderately correlated with BMI (p<0.05), except for STA1 on the left side. The course of AAs presented a high variability. CONCLUSION: These findings emphasize that the periorbital arteries carry with it a likelihood of ocular complication risks during injection. Targeting the supraperiosteal layer in the STA area and the supramuscular layer in the SOA area of the inferior forehead during injection seems reasonable, and an area within 1.0~2.0 cm from the midline should be avoided. Additionally, the high variability of AAs will enhance the understanding of the anatomy of the facial artery terminals. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Endoscopic endonasal surgical anatomy of the optic canal: key anatomical relationships between the optic nerve and ophthalmic artery.

PURPOSE: A detailed understanding of the neurovascular relationships between the optic nerve (ON) and the ophthalmic artery (OA) in the optic canal (OC) is paramount for safe surgery. We focused on the neurovascular anatomy of this area from both an endoscopic endonasal and transcranial trajectories to compare the surgical exposures and perspectives offered by these different views and provide recommendations to increase the intraoperative safety. METHODS: Twenty sides of ten formalin-fixed, latex-injected head specimens were utilized. The surgical anatomy and anatomical relationships of the OA in relationship to the ON along their intracranial and intracanalicular segments was studied from endoscopic endonasal and transcranial perspectives. RESULTS: Three types of OA-ON relationships at the origin of the OA were identified: inferomedial (type 1, 35%), inferior (type 2, 55%), and inferolateral (type 3, 10%). The endoscopic endonasal trajectory offers an inferomedial perspective of the ON-OA neurovascular complex, in which the OA, especially when located inferomedially, is first encountered. When comparing with the transcranial view, all OA were covered by the nerve, type 1 was located below the medial third, type 2 below the middle third, and type 3 below the lateral third of the OC. The mean extension of the intracanalicular portion of both OA and ON was 8.9 mm, while the intracranial portion of the OA and ON were 9.3 mm and 12.4 mm, respectively. The OA, endoscopically, is located within the inferior half of the OC, and occupies 39%, 43%, and 42% of the OC height at its origin, mid, and end points, respectively. The mean distance between the superior margin of the OC at its origin and superior margin of the OA is 1.4 mm. CONCLUSIONS: Detailed anatomical understanding of the OC, and the ON and OA at their intracranial and intracanalicular segments is paramount to safe surgery. When opening the OC dura endoscopically, our results suggest that a medial incision along the superior third of the OC with a proximal to distal direction is recommended to avoid injury of the OA.

Radiological and clinical correlations of the anterior ethmoidal artery in functional endoscopic sinus surgery.

OBJECTIVES: To correlate computed tomography findings and endoscopic localisation of the anterior ethmoidal artery during surgery, and to analyse the intranasal landmarks and abnormalities of the artery. METHOD: The anterior ethmoidal artery was studied with high-resolution computed tomography and endoscopic surgery in 30 patients undergoing functional endoscopic sinus surgery (group A), and with endoscopic dissection on 30 human cadavers (group B). RESULTS: The anterior ethmoidal artery was demonstrated on computed tomography in 25 patients and intra-operatively in 12 (group A). It was identified in 26 cadavers (group B). Dehiscence of bony canal and branching was noted in 10.53 per cent of cases. The mean (± standard deviation) intranasal length of the anterior ethmoidal artery was 7.29 (± 1.21) mm, the distance of the artery from the axilla of the middle turbinate was 16.24 (± 2.75) mm, and the mean distance from the ground lamella was 8.97 (± 1.46) mm. CONCLUSION: High-resolution computed tomography scanning prior to functional endoscopic sinus surgery is mandatory to identify the anterior ethmoidal artery. Endoscopically, the axilla of the middle turbinate and the ground lamella can serve as dependable reference points to identify the artery. Cadaver dissection improves understanding of anatomy.

Microanatomic Study of the Optic Canal.

BACKGROUND: The continuous development of microsurgical techniques to treat lesions in and around the optic canal (OC) emphasizes the need for an accurate understanding of the microanatomy of the region. METHODS: Forty anatomic specimens were studied, with emphasis on the OC. The sphenoid bone and related structures were decalcified, added to animal gelatin, cut into 1-mm thick slices, and observed through a surgical microscope. The OC was considered the course that contained exclusively the optic nerve (ON) and ophthalmic artery. RESULTS: The mean distance between the medial walls of the OC was 12.2 mm, and the OC had an average length of 12.06 mm. The OC has a horizontal oval shape in the proximal (internal) segment; a round shape in the middle segment; and a vertical oval shape in the distal (external) segment at the orbital cavity. In the middle segment of the OC, the thickest wall of the OC was the lateral (average: 0.68 mm), while the medial, inferior, and superior wall measures had averages of 0.75, 0.40, and 0.39 mm, respectively. The lateral wall of the sphenoid sinus is located under the OC, and the inferior wall of the OC separates both structures. The ophthalmic artery inside the OC was always located under the ON, between the dural sheaths, and had an average diameter of 1.03 mm. CONCLUSIONS: The neurovascular structures within the OC vary in size and shape. The anatomic knowledge of the OC and its variations allows better surgical results and minimizes the surgical morbidity.

Sphenoidal artery: review of the literature and analysis of a dissected arterially injected fetal orbit.

PURPOSE: The sphenoidal artery is considered a component of the complex and dangerous arterial anastomoses of the human orbitocranial region, particularly with the advent of interventional neuroimaging. The objective of this publication was to analyze the various descriptions of the sphenoidal artery in the literature as related to relevant photographs of a dissected arterially injected fetal middle cranial fossa and orbit. METHODS: Publications dealing with middle meningeal-ophthalmic arterial anastomoses, focusing on the sphenoidal artery, were reviewed. A relevant dissection of a fetal specimen was analyzed. RESULTS: The literature dealing with the sphenoidal artery is at times not in agreement. The nomenclature and anatomy of its passage through the superior orbital fissure or Hyrtl canal have variable descriptions. Photographs of the skull base of a dissected arterially injected fetal specimen show bilateral prominent orbital branches of the middle meningeal arteries. These branches entered both orbits in a course similar to the diagrammatic representations of the sphenoidal artery, and give rise to several major intraorbital arteries. This study provides the only photographic image in the literature of this variation in a human fetal anatomic dissection. CONCLUSIONS: Review of the literature dealing with the sphenoidal artery shows inconsistent nomenclature and conflicting descriptions of its anastomotic connections, and varying evolutionary and embryologic theories. Analysis of the dissected fetal skull base indicates that the sphenoidal artery is not a distinct artery but just a middle meningeal orbital arterial branch, an important component of the complex and dangerous arterial anastomoses of the human orbitocranial region.

Anatomic and Embryologic Analysis of the Dural Branches of the Ophthalmic Artery.

The ophthalmic artery has one of the most fascinating embryologic developments among the craniofacial arteries. Most of the ophthalmic artery orbital branches develop from the formation and regression of the stapedial artery and share their origin with dural branches of the ophthalmic artery. The concomitant embryologic development of the ophthalmic artery and middle meningeal artery explains adequately the important varieties of anastomosis between these 2 arteries. It also explains the presence of many dural branches from the ophthalmic artery. In this review, we focused on dural branches of the ophthalmic artery with the description of rare variations possible, in particular the ophthalmic artery origin of the middle meningeal artery and the ophthalmic artery origin of the marginal tentorial artery.

Role of the ophthalmic artery in the endovascular treatment for intracranial vascular diseases.

The ophthalmic artery (OA) is a crucial artery. Centered at the OA, there are numerous extracranial-intracranial anastomoses. The OA and its collaterals can be involved in some intracranial vascular diseases. So, it is very important to understand its specific anatomy, variation, and role in different neurovascular diseases. The OA has various anomalies both in the origin and collateral circulation. When performing endovascular treatment (EVT), the OA may suffer unexpected embolization through the numerous dangerous anastomoses. In case of a dural arteriovenous fistula or brain arteriovenous malformation mainly fed by the OA, the OA can be the passage of EVT, during which the central retinal artery could be injured. During interventional recanalization of steno-occlusive diseases of the internal carotid artery, dissection at the cavernous segment could progress to the OA segment and occlude the origin of OA. Under the circumstance of moyamoya disease, the OA can provide collateral flow to the anterior cerebral artery. When performing EVT for OA aneurysm concurrent with moyamoya disease, the parent OA should be preserved. After placement of a flow-diverting device for ophthalmic ICA aneurysm, the covered OA could experience spontaneous occlusion, leading to visual disturbance. Hence, the OA is an extremely important artery in the EVT for intracranial vascular diseases. In this article, we would extensively review the related literature to increase our understanding of the role of OA in intracranial vascular diseases. In addition, some illustrative cases would also be provided.

A case series: 3-dimensional computed tomographic study of the superior orbital vessels: Superior orbital arcades and their relationships with the supratrochlear artery and supraorbital artery.

BACKGROUND: Vascular complications from periorbital intravascular filler injection are major safety concerns. OBJECTIVE: To thoroughly describe the superior orbital vessels near the orbital rim and propose considerations for upper eyelid and forehead injections. METHODS: Fifty-one cadaver heads were infused with lead oxide contrast media through the external carotid artery, internal carotid artery, and facial and superficial temporal arteries. Computed tomography (CT) images were obtained after contrast agent injection, and 3-dimensional CT scans were reconstructed by using a validated algorithm. RESULTS: Eighty-six qualified hemifaces clearly showed the origin, depth, and anastomoses of the superior orbital vessels, which consistently deployed 2 distinctive layers: deep and superficial. Of all hemifaces, 59.3% had deep superior orbital vessels near the orbital rim, including 44.2% with deep superior orbital arcades and 15.1% with deep superior orbital arteries, which originated from the ophthalmic artery. Additionally, 97.7% of the hemifaces had superficial superior orbital arcades, for which 4 origins were identified: ophthalmic artery, superior medial palpebral artery, angular artery, and anastomosis between the angular and ophthalmic arteries. LIMITATIONS: The arterial depth estimated from 3-dimensional CT needs to be confirmed by standard cadaver dissection. CONCLUSION: This study elucidated novel arterial systems and proposed considerations for upper eyelid and forehead injections.

Site of Origin of the Ophthalmic Artery Influences the Risk for Retinal Versus Cerebral Embolic Events.

BACKGROUND: Embolic events leading to retinal ischemia or cerebral ischemia share common risk factors; however, it has been well documented that the rate of concurrent cerebral infarction is higher in patients with a history of transient ischemic attack (TIA) than in those with monocular vision loss (MVL) due to retinal ischemia. Despite the fact that emboli to the ophthalmic artery (OA) and middle cerebral artery share the internal carotid artery (ICA) as a common origin or transit for emboli, the asymmetry in their final destination has not been fully explained. We hypothesize that the anatomic location of the OA takeoff from the ICA may contribute to the differential flow of small emboli to the retinal circulation vs the cerebral circulation. METHODS: We report a retrospective, comparative, case-control study on 28 patients with retinal ischemia and 26 patients with TIA or cerebral infarction caused by embolic events. All subjects underwent either computed tomography angiography or MRA. The location of the ipsilateral OA origin off the ICA was then graded in a blinded fashion and compared between cohorts. Vascular risk factors were collected for all patients, including age, sex, hypertension, hyperlipidemia, arrhythmia, diabetes, coronary artery disease, and smoking. RESULTS: We find that in patients with retinal ischemia of embolic etiology, the ipsilateral OA takeoff from the ICA is more proximal than in patients with cerebral infarcts or TIA (P = 0.0002). We found no statistically significant differences in demographic, vascular, or systemic risk factors. CONCLUSIONS: We find that the mean anatomical location of the OA takeoff from the ICA is significantly more proximal in patients with MVL due to retinal ischemia compared with patients with TIA or cerebral ischemia. This finding contributes significantly to our understanding of a long observed but poorly understood phenomenon that patients with MVL are less likely to have concurrent cerebral ischemia than are patients with TIA.

Anatomic features of the cranial aperture of the optic canal in children: a radiologic study.

OBJECTIVE: This study aimed to peruse anatomic features of the cranial aperture of the optic canal (CAOC) for obtaining an extended morphometric dataset in children. METHODS: Computed tomography images of 200 children were included in this retrospective work to analyze the shape, location and diameters of the CAOC. RESULTS: The CAOC area, width and height were observed as 17.53 ± 2.80 mm2, 6.12 ± 0.84 mm, and 4.35 ± 0.64 mm, respectively. The angle of the optic canal in axial plane was found as 39.28 ± 5.13°, while in sagittal plane as 16.01 ± 6.76°. The distance between the CAOC and the midsagittal line was 7.17 ± 1.48 mm. The CAOC was measured as 54.04 ± 5.23 mm and 42.55 ± 3.28 mm away from the anterior and lateral boundary of the anterior skull base, respectively. The CAOC shape was described as the tear-drop (186 foramina, 46.5%), triangular (156 foramina, 39%), oval (47 foramina, 11.8%), and round (11 foramina, 2.8%). CONCLUSION: The depth, angle and diameter measurements belonging to the CAOC were changing according to its shape or demographic data (e.g., sex and age). Therefore, preoperative radiologic evaluation containing the shape, location and size of the CAOC should be considered by multidisciplinary operating teams in terms of surgical interventions such as implant positioning.

Ocular echobiometry and resistivity Index of external ophthalmic artery in agoutis (Dasyprocta prymnolopha)

Veterinary Ophthalmology provides complementary information for the diagnosis of ocular pathologies. Studies in wild species are essential. Among the diagnostic techniques in ophthalmology, two-dimensional ultrasonography stands out. The agouti is a rodent belonging to the Dasyproctidae family that has been widely used as an experimental model. For these animals, sight is one of the crucial senses for their survival. The aim of this study was to evaluate the effectiveness of the two-dimensional ocular ultrasound technique to obtain anatomical measurements and the external ophthalmic artery resistivity index, presumably normal in the species Dasyprocta prymnolopha. Forty eye bulbs of 20 adult rodents of the species were evaluated by ultrasonography. In these animals, B-mode echobiometry was performed using the transpalpebral approach and the hemodynamic study of the external ophthalmic artery using the color Doppler technique. All examinations were initiated by the left eye bulb and all measurements were performed by only one examiner. The collected data related to echobiometry were analyzed using Bioest 5.0 for Windows. Initially, normality was tested using the Shapiro-Wilk test for each parameter, then the paired t-test was performed, comparing right and left eyes, and a significance level of 5% (P < 0.05) was adopted. Based on the methodology used, the following values were obtained for the right and left eyeballs, respectively: anterior chamber thickness - mean of 1.28 ± 0.3 mm and 1.22 ± 0.1 mm; lens thickness - 8.27 ± 0.9 mm and 8.11 ± 0.9 mm; vitreous chamber thickness - 5.35 ± 0.48 mm and 5.30 ± 0.47 mm and axial length - 12.7 ± 0.9 mm and 13 ± 0.68 mm. The mean external ophthalmic artery resistivity values were 0.4305 ± 0.0390 and 0.4258 ± 0.0387 (right and left eye, respectively), characterizing a low resistance. There was no statistical difference between the right and left eyeballs in any of the studied parameters. The use of the convex transducer was feasible, promoting adequate contact with the ocular surface and images of satisfactory quality for obtaining measurements, similar to what was observed in studies evaluating the ocular biometry of primates and dogs. The anterior chamber thickness values in this experiment did not differ statistically between the antimers, as well as observed for dogs. The data obtained for lens thickness did not differ statistically for antimers, like those obtained for other rodent species evaluated with the same methodology. The mean values of vitreous chamber thickness were like those observed in chinchillas but correspond to about half of that obtained for capybaras. In this study, the external ophthalmic artery was characterized in all animals, but obtaining the spectral tracing was difficult due to its fine caliber. In wild animals, and especially in wild rodents, there are few data reporting the resistivity of the ophthalmic artery, and there is a lack of studies, which can be explained by the behavioral characteristics of defense and by the high susceptibility to stress in capture, since the performing the technique requires, as in other procedures, the use of chemical containment. (AU)

Clinical implications in orbital and pterional flap surgeries as well as radioimaging studies to determine topographical prevalence and characterization of meningo-orbital foramen in orbits of the Indian population / Implicaciones clínicas en cirugías de colgajo orbitario y pterional, así como estudios de radioimagen para determinar la prevalencia topográfica y la caracterización del foramen meningoorbitario en órbitas de la población india

SUMMARY: The pear-shaped bony orbit connects with intracranial cavity via foramina's and fissures. The Meningo-orbital Foramen (MOF) is usually present in greater wing of sphenoid close to lateral edge of Superior orbital fissure. It provides a route for an anastomosis between the orbital branch of the middle meningeal artery (MMA) and recurrent meningeal branch of Ophthalmic Artery (OA) and hence, risk of damage during surgeries can occur. To verify occurrence and location, with morphology of MOF in dry orbits and the impending clinical hazards in surgeries pertaining to the orbit, document and analysis it to determine a standardized guideline. The presence for MOF was studied in 446 dry orbits with its location from the supra orbital margin (SOM), front zygomatic suture (FZS), the lateral tubercle of Whitnall (WT)and the lateral end of superior orbital fissure (SOF) along with its patency, laterality and number of foramina's present. Nylon probes, long divider/pins, compass and Vernier callipers was used to check the patency and various parameters. The study noted the percentage prevalence of MOF as 69 % with communication with middle cranial fossa (MCF) being 76 % of 69 % and the average distance from SOM, FZS, WT and lateral end of SOF being 35.58 mm, 24.9 mm, 26.6 mm and 0.92 mm. On comparison with various population studies, certain similarities and differences with regards to different parameters were noted. Prevalence of MOF was mostly unilateral and showed multiple foramina, that can act as channels for arteries, a variant of MMA or OA, that supply orbital structures or tumour growths. Thus, awareness of this variation is of prime importance to ophthalmologists and neurosurgeons as well as interventional radiologists, in preventing haemorrhagic condition which could further raise the difficulties in operative procedures and surgical outcomes.

RESUMEN: La órbita ósea en forma de pera se conecta con la cavidad intracraneal a través de forámenes y fisuras. El foramen meningoorbitario (MOF) suele estar presente en el ala mayor del esfenoides cerca del margen lateral de la fisura orbitaria superior. Proporciona una ruta para una anastomosis entre la rama orbitaria de la arteria meníngea media (MMA) y la rama meníngea recurrente de la arteria oftálmica (OA) y, por lo tanto, puede ocurrir riesgo de daño durante las cirugías. Para verificar la ocurrencia y ubicación, con la morfología de MOF en órbitas secas y los peligros clínicos inminentes en cirugías de la órbita, documentarlo y analizarlo para determinar una pauta estandarizada. Se estudió la presencia de MOF en 446 órbitas secas desde el margen supraorbitario (MOS), sutura cigomática frontal (FZS), el tubér- culo lateral de Whitnall (WT) y el extremo lateral de la fisura orbitaria superior (SOF) junto con su permeabilidad, lateralidad y número de forámenes presentes. Se utilizaron sondas de nailon, divisores / pasadores largos, brújula y calibradores Vernier para comprobar la permeabilidad. En el estudio se pudo observar que la prevalencia porcentual de MOF era del 69 %, siendo la comunica- ción con la fosa craneal media (MCF) del 76 % del 69 % y la distancia promedio desde SOM, FZS, WT y el extremo lateral de SOF era de 35,58 mm, 24,9 mm, 26,6 mm y 0,92 mm. En comparación con varios estudios de población, se observaron ciertas similitudes y diferencias con respecto a diferentes parámetros. La prevalencia de MOF fue mayoritariamente unilateral y mostró múltiples forámenes, que pueden actuar como canales para las arterias, una variante de MMA u OA, que irrigan estructuras orbitarias o crecimientos tumorales. Por lo tanto, la conciencia de esta variación es de primordial importancia para los oftalmólogos y neurocirujanos, así como para los radiólogos intervencionistas, en la prevención de una enfermedad hemorrágica que podría aumentar aún más las dificultades en los procedimientos y los resultados quirúrgicos.

Valores ecobiométricos e índice de resistividade da artéria oftálmica externa em catetos (Tayassu tajacu, Linnaeus, 1758) / [Ecobiometric values and resistivity index of the external ophthalmic artery in collared peccaries (Tayassu tajacu Linnaeus, 1758)]

Foram avaliados ultrassonograficamente, pela via transpalpebral, 28 bulbos oculares de 14 catetos adultos, através de técnica padronizada pelo operador. Adicionalmente foi realizado o estudo hemodinâmico da artéria oftálmica externa pela técnica de Doppler colorido. Os dados coletados foram analisados estatisticamente pelo programa Bioestat 5.0 for Windows, adotando-se 5% de significância. Com a metodologia empregada, obtiveram-se os seguintes valores para os globos oculares direito e esquerdo, respectivamente D1: 1,72 ± 0,29mm e 1,76 ± 0,40mm; D2: 9,95 ± 1,08mm e 10,6 ± 0,99mm; D3: 7,42 ± 0,93mm e 7,45 ± 0,72mm e D4: 17,6 ± 0,78mm e 17,8 ± 0,59mm. Os valores médios do índice de resistividade da artéria oftálmica externa foram 0,435 ± 0,02 e 0,448 ± 0,02 (globos oculares direito e esquerdo, respectivamente). Não houve diferença estatística quanto aos antímeros oculares em nenhum dos parâmetros estudados. Conclui-se que a ecobiometria ocular e a Dopplerfluxometria da artéria oftálmica na espécie Tayassu tajacu é executável e reprodutível, desde que haja domínio do examinador em relação à anatomia e à técnica adequada. Os valores inferidos neste estudo servem de referência para médicos veterinários no diagnóstico de doenças oculares.(AU)

Twenty-eight ocular bulbs of fourteen adult catheters were evaluated through ultrasound with the transpalpebral approach, using a standardized technique by the operator. Additionally, the hemodynamic study of the external ophthalmic artery was performed using the color Doppler technique. The collected data were statistically analyzed by the Bioestat 5.0 for Windows program, adopting 5% of significance. With the methodology employed, the following values were obtained for the right and left eyeballs, respectively D1: 1.72 ± 0.29mm and 1.76 ± 0.40mm; D2: 9.95 ± 1.08mm and 10.6 ± 0.99mm; D3: 7.42 ± 0.93mm and 7.45 ± 0.72mm and D4: 17.6 ± 0.78mm and 17.8 ± 0.59mm. The mean resistivity index values of the external ophthalmic artery were 0.435 ± 0.02 and 0.448 ± 0.02 (right and left eyeball respectively). There was no statistical difference regarding ocular antimers in any of the studied parameters. We concluded that ocular echobiometry and ophthalmic artery Doppler flowmetry in Tayassu tajacu species is executable and reproducible, provided there is an examiner's domain regarding the anatomy and proper technique. The values inferred in this study serve as a reference for veterinarians in the diagnosis of eye diseases.(AU)

Radioanatomic Characteristics of the Posteromedial Intraconal Space: Implications for Endoscopic Resection of Orbital Lesions.

BACKGROUND AND PURPOSE: Imaging is essential in the diagnostic work-up of patients with orbital lesions. The position of an orbital lesion relative to the inferomedial muscular trunk of the ophthalmic artery determines endoscopic resectability, anticipated technical difficulty, and patient morbidity. Although the inferomedial muscular trunk is not readily identifiable on preoperative imaging, we hypothesize that it is spatially approximate to the location where the ophthalmic artery crosses the optic nerve. Our aim was to determine whether the ophthalmic artery-optic nerve crosspoint anatomically approximates the inferomedial muscular trunk in a cadaver study and can be appreciated on imaging of known posteromedial orbital lesions. MATERIALS AND METHODS: Dissection was performed on 17 fresh-frozen cadaver orbits to assess the relationship between the inferomedial muscular trunk and ophthalmic artery-optic nerve crosspoint. Retrospective review of imaging in 9 patients with posteromedial orbital lesions assessed posteromedial orbital compartment characteristics and the ability to locate the ophthalmic artery-optic nerve crosspoint. RESULTS: In our cadaver study, the mean distance between the ophthalmic artery-optic nerve crosspoint and the inferomedial muscular trunk was 1.21 ± 0.64 mm. Retrospectively, the ophthalmic artery-optic nerve crosspoint was identifiable in 9/9 patients, whereas the inferomedial muscular trunk was not identifiable in any patient. Total or partial effacement of the posteromedial intraconal fat triangle was observed in 9/9 patients. CONCLUSIONS: This study of neurovascular relationships within the posteromedial orbit demonstrates that the ophthalmic artery-optic nerve crosspoint closely approximates the inferomedial muscular trunk and can be seen in patients with posteromedial orbital lesions. Posteromedial intraconal fat effacement may help to localize these lesions. These findings may facilitate multidisciplinary communication and help predict lesion resectability and patient outcomes.

Evaluation of the anastomoses between the ophthalmic artery and the middle meningeal artery by superselective angiography.

PURPOSE: There are three anastomoses between the ophthalmic artery (OA) and the middle meningeal artery (MMA): the anastomotic branch with MMA, the recurrent meningeal branch and the anterior falx artery. We aimed to evaluate the anastomotic branches between the OA and the MMA on superselective angiograms of pediatric patients with retinoblastoma. MATERIALS AND METHODS: We evaluated 126 angiographies performed on children with retinoblastoma. The mean diameter and angiographic visibility percentage of the anastomotic branches between the OA and the MMA were examined according to age group and sex. RESULTS: The mean diameter of anastomotic branch with MMA was measured 0.58 ± 0.13 mm and we found this branch in 15 of 126 angiographic images (11.9%). We detected the recurrent meningeal branch in 47 of total images (37.3%). The recurrent meningeal branch arose 85.1% from the lacrimal artery, 8.5% from the anastomotic branch with MMA and 6.4% directly from the OA. The mean diameter of this artery was measured 0.21 ± 0.06 mm. Anterior falx artery was found in 86 of 126 angiographic peocedures (68.3%) and the mean diameter was measured 0.22 ± 0.06 mm. CONCLUSION: Knowledge of the anastomoses between the OA and the MMA system are all necessary to perform safe and successful endovascular and surgical procedures involving the orbital region.

The Functional Anatomy of the Ophthalmic Angiosome and Its Implications in Blindness as a Complication of Cosmetic Facial Filler Procedures.

BACKGROUND: Blindness following facial filler procedures, although rare, is devastating, usually acute, permanent, and attributed to an ophthalmic artery embolus. However, blindness may be delayed for up to 2 weeks, sometimes following injection at remote sites, suggesting alternative pathways and pathogenesis. METHODS: Seeking solutions, fresh cadaver radiographic lead oxide injection, dissection, and histologic studies of the orbital and facial pathways of the ophthalmic angiosome, performed by the ophthalmic artery and vein, both isolated and together, and facial artery perfusions, were combined with total body archival arterial and venous investigations. RESULTS: These revealed (1) arteriovenous connections between the ophthalmic artery and vein in the orbit and between vessels in the inner canthus, allowing passage of large globules of lead oxide; (2) the glabella, inner canthi, and nasal dorsum are the most vulnerable injection sites because ophthalmic artery branches are anchored to the orbital rim as they exit, a plexus of large-caliber avalvular veins drain into the orbits, and arteriovenous connections are present; (3) choke anastomoses between posterior and anterior ciliary vessels supplying the choroid and eye muscles may react with spasm to confine territories impacted with ophthalmic artery embolus; (4) true anastomoses exist between ophthalmic and ipsilateral or contralateral facial arteries, without reduction in caliber, permitting unobstructed embolus from remote sites; and (5) ophthalmic and facial veins are avalvular, allowing reverse flow. CONCLUSION: The authors' study has shown potential arterial and venous pathways for filler embolus to cause blindness or visual field defects, and is supported clinically by a review of the case literature of blindness following facial filler injection.

Analysis of anatomical variation of the inclination of lamellas attached to the skull base and its correlation with the anterior ethmoidal artery floating in the ethmoid sinus for use in endoscopic sinus surgery.

PURPOSE: Attention to the inclination of lamellas attached to the skull base, including the basal lamella of the middle turbinate, facilitates the intraoperative identification of each lamella without requiring the use of a navigation system. We classified the inclination between the lamella and the skull base in preoperative computed tomography (CT) images and examined the relationship between the lamellas attached to the skull base, including the basal lamella of the middle turbinate, and the position of the anterior ethmoidal artery (AEA). We aimed to develop a preoperative classification to help prevent intraoperative injury of the AEA. METHODS: We retrospectively investigated the paranasal sinus sagittal section CT slices of 366 sides of 183 patients to assess the inclination of lamellas attached to the skull base and the AEA location. We also reviewed the AEA position, its correlation with the supraorbital ethmoid cell, and the lateral lamella of the cribriform plate. RESULTS: We classified the lamella inclination at the skull base as the anterior direction, perpendicular direction, and posterior direction types. Lamellas containing a floating AEA inclined in the anterior direction toward the skull base were observed in 68.9% of sides, inclination in the perpendicular direction was noted in 30.5% of sides, and inclination in the posterior direction was noted in 0.5% of sides. CONCLUSION: It is easier to identify the AEA intraoperatively when the lamella inclination of the skull base attachment is recognized based on preoperative CT findings. This approach could be applied to all paranasal sinus lamellas and assist in identifying the AEA and other nearby structures.

High frequency of ophthalmic origin of the middle meningeal artery in chronic subdural hematoma.

PURPOSE: Embolization of middle meningeal artery (MMA) has been proposed for postoperative recurrences and primary treatment of chronic subdural hematoma (CSDH). This endovascular intervention is safe only when MMA originates from the internal maxillary artery. The aim of this study was to report an unusual high frequency of MMA originating from the ophthalmic artery, which prohibits this treatment. METHODS: In this retrospective study, we reviewed the anatomical origin of the MMA in patients with CSDH who were referred to our center for endovascular treatment between January 2017 and May 2019 (42 patients with 58 CSDH). We compared the prevalence of this variant in a control group of 66 patients who underwent embolization for epistaxis during the same period. RESULTS: In CSDH group, MMA originated from the ophthalmic artery in 8 out of 58 internal carotid arteries (13.8%). In the control group, this variant was observed in only 1 case out of 131 internal carotid arteries (0.7%) (OR = 20; 95% CI 2.6 to 925.2, p = 0.0003). CONCLUSION: In this study, we report an extremely high prevalence of MMA originating from the ophthalmic artery in CSDH. In the hypothesis of prospective studies, a priori recognition of this variant will be necessary in order to exclude patients in whom endovascular treatment will not be feasible.

Anatomical and ultrasound-based injections for sunken upper eyelid correction.

BACKGROUND: A needle or a cannula can be safely used during filler injection procedures to correct a sunken upper eyelid. To date, there are no precise injection points recommended that are based on an anatomical study. OBJECTIVE: This study systematically investigated the vascular pattern and depth of forehead arteries at the periorbital area of upper eyelid. METHODS: Twenty cadavers were dissected in this study. Additional data were obtained from 30 healthy volunteers using Doppler ultrasound imaging with high-frequency probe. RESULTS: The ophthalmic artery divided into two opposite primary branches: the superior and inferior orbitoglabellar arteries running along the orbital rim. After the supratrochlear artery arose from the superior orbitoglabellar artery at the medial eyebrow, the supraorbital artery either divided from this artery near the supraorbital foramen or emerged as an individual artery from the supraorbital notch. The inferior orbitoglabellar artery gave off the radix artery superior to the medial canthal tendon. The radix artery divided into two opposite branches: the dorsal nasal artery going to the nose and the paracentral artery going to the glabella. Ultrasound imaging revealed a subcorrugator space that a cannula can safely pass through. At the supraorbital foramen/notch, the supraorbital artery traveled very close to the bone. Based on the anatomical data collected, the following injection points for a needle and a cannula technique are recommended. CONCLUSION: Correction of a sunken upper eyelid is a dangerous procedure which should be performed only by experienced physicians. However, with precise anatomical knowledge and correct techniques, optimal outcomes can be safely achieved.