Optic Canal Research Articles

How I do it - endoscopic endonasal optic nerve decompression for traumatic optic nerve neuropathy.

Traumatic optic neuropathy (TON) consists of damage to the optic nerve following head injury and affects about 0.5-5% of patients with closed head injuries. It is characterized by a sudden decrease in visual acuity and/or visual field loss. Surgical treatment is usually warranted when ongoing compression occurs at the level of the optic canal. We describe the technical nuances of endoscopic endonasal approach for compressive TON and add evidence supporting this approach as a valid option to treat this condition.

Endoscopic endonasal decompression for traumatic optic nerve injury: how I do it.

Endoscopic Endonasal Decompression for Traumatic Optic Nerve Injury has become an established endoscopic technique. However, Poor sphenoid sinus pneumatization often obscures landmarks, elevating the risk to vital neurovascular structures. By decompressing the orbital apex region and determining the contour of the optic nerve, sequential decompression of the medial wall, superomedial wall, and inferomedial wall of the optic canal. This surgical technique can gradually reveal the contour of the optic canal when the anatomical landmarks on the lateral wall of the sphenoid sinus are unclear, ensuring the surgery can be completed safely and effectively.

A Case of Compressive Optic Neuropathy Caused by Orbital Emphysema

Purpose: We report a patient with compressive optic neuropathy (CON) in whom visual acuity (VA) was restored after removing conjunctival emphysema through the conjunctiva.Case summary: A 55-year-old man was transferred to emergency department complaining of decreased VA in the right eye after trauma to the right temporal side of the head. The best-corrected visual acuity (BCVA) was 0.6 in the right eye. We confirmed a relative afferent pupillary defect and limited eye movement inferiorly in the right eye. The patient had blown his nose several times while being transferred to the hospital. On silt-lamp examination, there was conjunctival emphysema of the right eye. Orbital computed tomography showed a medial wall fracture of the right orbit and orbital emphysema above the optic canal. The P100 wave was delayed in the visual evoked potential (VEP) exam, and there was a decreased peripheral visual field on the Humphrey visual field test. Based on these findings, we diagnosed CON and treated him accordingly. To decompress the intra-orbital area, we injected mannitol intravenously, applied intraocular pressure-lowering and antibiotic eye drops in the right eye, and removed part of the conjunctival emphysema through the conjunctiva. At the 3-week follow-up, the BCVA had improved to 1.0 in the right eye with a normalized P100 wave on the VEP exam.Conclusions: In a case of CON caused by orbital emphysema after trauma, it is important to decrease the intra-orbital pressure as soon as possible to enable a good prognosis for the VA.

Rapid Amplification of Cerebrospinal Fluid Pressure as a Possible Mechanism for Optic Nerve Sheath Bleeding in Infants With Nonaccidental Head Injury.

Subdural hemorrhage along the optic nerve (ON) is a histopathological indicator of abusive head trauma (AHT) in infants. We sought to determine if this bleeding could be caused by an abrupt increase in intracranial pressure transmitted to cerebrospinal fluid (CSF) at the optic foramen (OF). A theoretical model is developed to simulate the effect of a pressure perturbation of maximal amplitude P applied at the optic foramen for a short duration T on the CSF-filled ON subarachnoid space (ONSAS). The ONSAS is modelled as a fluid-filled channel with an elastic wall representing the flexible ONSAS-arachnoid/dura interface. A constitutive law describing the relationship between CSF pressure and ONSAS deformation is inferred from published measurements. CSF pressure profiles along the ONSAS are examined systematically over a broad range of P and T. The pressure perturbation initiated at the OF produces a pressure wave that stretches the ONSAS. This wave propagates rapidly along the ONSAS toward the scleral end of the ON, where it is reflected back toward the brain. For sufficiently small T a shock wave with amplification up to six times larger than P over a timescale of tens of milliseconds is observed at the scleral end of the ON. Comparatively smaller amplifications are observed for slower perturbations. A sudden increase in CSF pressure in the cranial cavity can cause a rapid expansion of the ONSAS, which may lead to rupture of the bridging blood vessels. Our study predicts a plausible mechanism for subdural hemorrhage that occurs in abusive head trauma in infants.

7219 Ocular Findings in Jansen Metaphyseal Chondrodysplasia

Abstract Disclosure: F. Obiezu: None. K. Pan: None. A. Ninan: None. K.L. Roszko: None. L.S. Weinstein: None. C.R. Ferreira: None. R.I. Gafni: None. T. Magone De Quadros Costa: None. M.T. Collins: None. S. Jha: None. Jansen Metaphyseal Chondrodysplasia (JMC) is an ultra-rare disorder, with only 30 patients estimated to have the disease globally. It is caused by heterozygous pathogenic variants in PTHR1 that result in constitutive activation of parathyroid hormone type 1 receptor (PTHR1) signaling. A detailed description of craniofacial manifestations of the disease is lacking. Here we characterize the ophthalmological manifestations in patients with JMC. Six patients (4 males, 67%) with genetically confirmed JMC underwent a detailed ophthalmological evaluation, spectral-domain optical coherence tomography (OCT), craniofacial CT and 18F-NaF PET/CT scans. Median age at the time of the visit was 27.5 [IQR: 29] years. On physical examination, all patients were noted to have widely spaced eyes; 5 of the 6 had down slanted palpebral fissures, proptosis, or ptosis. Two patients had incomplete or defective closure of the eyelids (lagophthalmos), of which one had a history of progressive right facial nerve palsy with profuse epiphora. The second patient had central visual field defects, bilateral moderate optic disc pallor and bilateral retinal nerve fiber layer (RNFL) atrophy on OCT exam with bilateral optic canal narrowing on CT. Notably, comparison of these findings with a prior scan performed 5 years earlier showed progressive decrease in RNFL bilaterally. This patient had a history of prolonged intravenous bisphosphonate therapy, initiated in infancy for hypercalcemia and continued for over a decade. A third patient had normal vision, subtle temporal pallor of the optic nerve heads on dilated fundus exam, normal average RNFL, but decreased retinal ganglion cell layer analysis (GCA) on OCT. GCA was decreased in 4 of the 6 patients compared to age-matched reference range indicating a chronic optic nerve atrophic process. These data represent the first comprehensive report of the ophthalmologic findings in a cohort of patients with JMC. They demonstrate that patients with JMC have significant eye findings that appear to be more prevalent and pronounced with age. This suggests age-related, progressive optic neuropathy, which can be assessed by demonstrating OCT retinal GCA and RNFL loss and, may be a feature of JMC. The benefit and effect of long-term bisphosphonate therapy in patients with JMC remains unclear. Patients with JMC should undergo regular ophthalmologic examination including optic nerve OCT, visual field testing, and craniofacial imaging. Presentation: 6/1/2024

Analysis of risk factors for patients with traumatic optic neuropathy and comparison of visual outcomes of management strategies

BackgroundTraumatic optic neuropathy (TON) is a rare complication of facial trauma that results in vision loss. Clinical diagnosis of TON is based on a history of head trauma and an ophthalmic examination; however, the risk factors for TON and the ideal treatment strategy remain undetermined. This study investigated the predictive risk factors for TON and analyzed the effectiveness of current treatments with respect to visual outcomes in patients with TON. MethodsThis study retrospectively enrolled patients with periorbital facial bone fracture between 2008 and 2019. Initial facial bone computed tomography, ophthalmic exam results, initial Glasgow Coma Scale, and Injury Severity Score (ISS) were recorded. This study classified patients into 4 intervention groups (i.e., medication, surgery, combination therapy, and observation) to compare the outcome of visual acuity. ResultsThis study enrolled 1168 patients with facial bone fractures, 93 (7.96%) of whom were diagnosed as having TON. Independent risk factors for TON included optic canal fracture, medial orbital wall fracture, retrobulbar hematoma, and head Abbreviated Injury Scale ≥ 4. Patients with TON who initially presented with no light perception tended to have poor final visual acuity (VA) outcomes. The results indicated no significant difference in VA improvement among patients receiving observation, mega-dose corticosteroid therapy, surgical decompression, or combined steroid therapy and decompression. ConclusionClinicians can achieve early prediction of TON in patients with an initial unconscious state and the determined risk factors. The results indicated that conservative observation yielded noninferior VA outcomes in patients with TON compared with those receiving medication or surgical treatment.

Laser Scanning Morphometric Measurements of the Main Orbital Communications in Dry Human Skulls

Background and Objectives: This research investigated the morphometric dimensions of the optic foramen (OF), superior orbital fissure (SOF) and inferior orbital fissure (IOF), using indirect measurement techniques such as laser scanning, making it likely the first study of its kind. This study aimed to identify the morphometric variability of the main orbit communications and to highlight the differences between genders. Materials and Methods: The anthropometric study was conducted on sixty dry skulls (120 orbits) of adults aged between 20 and 70 years. Measurements of orbital communications were made using the RS6 laser scanner. The orbital parameters that were investigated are as follows: length and width of the SOF and IOF, and height and width of the OF. Results: In males, the average height of the OF was 8.27 mm and 8.13 mm in females, while the average width of the OF was 6.34 mm in males and 5.83 mm in females. The SOF average length was 21.09 mm in males and 17.58 mm in females. The widths of the SOF in the three thirds (anterior, middle and posterior) in males were 5.14/4.77/7.11 mm and 2.28/3.48/5.80 mm in females. The average length of the IOF was 33.05 mm in males and 32.30 mm in females. The widths of the IOF in the three thirds (anterior, middle and posterior) were 5.61/3.92/4.70 mm in males and 7.24/4.68/4.08 mm in females. Conclusions: The OF height and width were higher in males compared to females. The SOF length and width were higher in males compared to females. The IOF length was higher in males for the right orbit and higher in females for the left orbit. The IOF width for both orbits was higher in females in the anterior and middle third, and higher for males in the posterior third. Evaluation of dry skulls using laser scanning is reliable and recommended for data accuracy. Laser scanning can become a usable method for all indented and hard-to-reach regions of the cranial skeleton.

Microsurgical Anatomy of the Common Tendinous Ring and Its Surgical Implications

BACKGROUND AND OBJECTIVES: The common tendinous ring (CTR), also known as the common annular tendon or annulus of Zinn, is a critical anatomic structure located at the convergence of the orbital apex, superior orbital fissure (SOF), optic canal, and the anterior aspect of the lateral sellar compartment. It plays a vital role in both neurosurgical and neuro-ophthalmological interventions. The aim of this study was to delineate the complex 3-dimensional (3D) topography of the CTR and explore its implications for surgical procedures. METHODS: Ten formalin-fixed skull base specimens from adult Chinese cadavers were meticulously dissected to investigate the morphology of the CTR, focusing particularly on its relationship with the 4 extraocular rectus tendons, the optic strut, the SOF, and the optic canal. Additional skull base specimens were subjected to 3D surface scanning, computed tomography, and histopathological examinations to deepen our understanding of the CTR's structural complexities. RESULTS: The CTR establishes a spatial, 3D tendinous assembly, encompassing 4 rectus tendons, 2 tendinous connections, and a singular common tendinous root. These components interlink to form a distinctive dual-ring configuration, featuring the optic foramen and the oculomotor foramen. The posterior part of the superior rectus tendon demarcates the common boundary between these 2 foramina. The oculomotor foramen itself serves as the central sector of the SOF. Precise incisions of the medial and lateral tendinous connections and fusions are essential for safely opening the CTR. CONCLUSION: The structural composition, interconnections, and dual-ring configuration of the CTR are crucial for precise and safe surgery of orbital apex and adjacent regions.

Cranio-Orbital Approach and Decompression of the Optic Nerves: A 2-Stage, 4-by-4-Step Approach to Improve Vision in Sellar and Parasellar Lesions.

Despite advances in cranial base techniques, surgery of the sellar and parasellar regions remains challenging because of complex neurovascular relationships. Lesions within this region frequently present with progressive visual deterioration caused by distortion and compression of the optic chiasm and nerves. In addition to the direct mass effect from mechanical forces acting on the optic apparatus, these lesions alter blood supply and reduce vascular perfusion, prompting surgical treatment to remove the lesion, alleviate compression, and improve blood flow to the optic nerve. We sought to describe a 2-stage, 4-by-4-step approach, broken down and described as a "four-by-four" technique for optic apparatus decompression and a wide approach to different sellar and parasellar lesions. We describe the operative nuances and key anatomic points in the microsurgical removal of sellar and parasellar lesions. The technique is illustrated with examples of different cases with pre- and follow-up MRI imaging and a brief overview of visual outcomes. The described technique has been demonstrated in various lesions in 5 patients. Patients presented with bilateral visual loss in 4 (80.0%) cases and with unilateral visual loss in 1 (20.0%) case. Improvement in visual function was noted in all cases, confirmed with visual acuity and visual field testing. The transcranial approach ("from above") remains an important surgical option for patients with excellent exposure and visualization of the sellar and parasellar regions. It permits early access to the optic canal for careful microsurgical decompression and relaxation of the optic nerve to preserve and improve its microvascularization and ultimately vision. The authors augmented the 2-stage, 4-by-4-step technique of decompression with elaborate illustrations of diverse sellar and parasellar lesions to demonstrate the versatility of this approach.

Optimizing the pterional approach in medial sphenoid wing meningioma: a detailed morphometric study on anterior clinoidectomy and its effect on operability score

BackgroundMedial sphenoid wing meningiomas are best treated through pterional craniotomy, as pterional craniotomy provides wide and multidirectional exposure of the anterior and middle cranial fossa. Anterior clinoidectomy can increase the exposure potential. To delineate the role of anterior clinoidectomy (AC) in the standard pterional craniotomy approach through the evaluation of operability score measures (manoeuvrability arc, depth of surgical field, and surgical angle of attack). All patients with inner sphenoidal wing meningioma who underwent microsurgical excision between February 2022 and October 2023 were enrolled in the study. Preoperative and postoperative imaging studies (MR contrast studies and 3D thin-slice CT scans of the brain) were performed to determine the tumour size, extent, and pattern of optic canal involvement by comparing pre- and postoperative operability score parameters.ResultsTwenty-five patients met our inclusion criteria: 2 males (8%) and 23 females (92%). The mean age (SD) was 49.08 ± 6.42 years, with an age range of 39–60 years. The preoperative visual manifestations were as follows: eight patients (32%) had mild visual impairment, five patients (20%) had moderate visual impairment, six patients (24%) had severe visual impairment, and five patients (20%) had blindness. There was a significant positive correlation between the operability score and extent of resection (gross total resection was correlated with a higher operability score) (r = 0.301, n = 25, p = 0.005).ConclusionsA well-planned manoeuvrable arc allows neurosurgeons to perform surgery with precision, ultimately impacting surgical outcomes and the potential for complete tumour removal with minimal patient morbidity.

Outcomes of Endoscopic Endonasal Surgery for Tuberculum Sellae and Planum Sphenoidale Meningiomas: A Retrospective Study.

To evaluate clinical outcomes and volumetric changes following endoscopic endonasal approach (EEA) for tuberculum sellae (TS) and planum sphenoidale (PS) meningiomas. Key objectives included evaluating pre- and postoperative tumor volumes, visual assessments and EEA-related complications. A single-center retrospective study was conducted at Foothills Medical Centre, University of Calgary, Canada, from 2009 to 2022 including 24 patients meeting inclusion criteria for midline skull base tumors, confirmed as WHO Grade I or II meningiomas with optic canal extension. EEA achieved gross total resection in 87.5% of cases, with a mean tumor volume reduction of 92.24%. Postoperatively, 91.67% exhibited visual improvement or stability. Cerebrospinal fluid leaks occurred in 12.5% of cases, necessitating revision surgery in one case. Persistent postoperative endocrine dysfunction affected 4.17%. Preoperative tumor volume did not demonstrate a correlation with complications. This study delivers reproducible data for pre- and postoperative tumor volume following the EEA after TS or PS meningiomas. The EEA demonstrated favorable radiographic and clinical outcomes in TS and PS meningiomas, achieving gross total resection with minimal morbidity.

Concurrent delayed recurrence of peripheral primitive neuroectodermal tumors in orbital and sellar/suprasellar regions in an older adult.

Peripheral primitive neuroectodermal tumors (pPNETs) are rare and aggressive small round cell tumors, tending to occur in the thoracic and paravertebral soft tissues in children and young adults. This report describes an exceptionally rare case of concurrent delayed recurrence of pPNET in the orbital and sellar/suprasellar regions in an older adult, with a discussion supported by a literature review. We report an 82-year-old woman with a history of orbital pPNETs resection at age 62, followed by gamma knife radiosurgery for local recurrence at age 66. She presented left eye pain, left eye protrusion, decreased vision in the right eye, and right homonymous hemianopia. MRI revealed extensive lesions in the left orbital cavity and sellar/suprasellar region, contiguous through the optic canal. The recurrent tumor was treated through a two-stage resection via transcranial and transsphenoidal approaches, which resulted in symptom improvement and a pathologic diagnosis of pPNETs. This case highlights a highly rare instance of late-onset orbital pPNETs recurrence in an elderly patient, with evidence suggesting tumor progression into the sellar/suprasellar regions through the optic canal.

Three-dimensional anatomical analysis of the optic nerve canal with virtual model based on CBCT

The optic nerve canal (ONC) is a fine skeletal structure that contains the optic nerve. However, it has not been thoroughly examined. This necessitates establishing a baseline knowledge of the geometrical and volumetric parameters of the ONC. The data of twenty patients who received a cone beam computed tomography examination were prepared using a voxel-based segmentation. The measurement was performed separately by two examiners on virtual skull models in stereolithography format in Geomagic Wrap®. The results showed that the volume of the ONC varied between 92.48 mm3 and 162.7 mm3 (M = 123.46 mm3, SD = 26.61 mm3). Sex-specific statistically significant differences in volume were detected only for the right side. The angle of the ONC to the skull base was independent of the diameter of the canal. Both the intrarater and interrater comparisons of the measurements showed high values of reproducibility of the results. This study showed that a virtual anatomical model provides a feasible and reliable method to investigate the ONC. The examination technique could have a wider range of application in anthropology and application in clinical medicine. Advances in the automation of radiological diagnostics and the digital analysis of X-ray images could help to reduce examination times.

Importance of Preoperative Pupillary Reflex in Traumatic Optic Neuropathy.

Traumatic optic neuropathy (TON) refers to a pathological condition caused by direct or indirect injury to the optic nerves. In the case of patients with traumatic brain injury, adequate vision evaluation is difficult in many cases due to altered mentality. In order to address this problem, we investigated preoperative pupillary light reflex in TON patients as a predictive factor of surgical outcomes after optic nerve decompression. From April 2020 to September 2022, we enrolled patients who were diagnosed with TON and underwent endoscopic optic nerve decompression at our institution. Vision and pupil reflex tests were performed by an ophthalmologist before and after surgery. Seven patients were enrolled. Their ages ranged from 9 to 78 years and all were male. Among the 7 patients, the patient whose pupillary light reflex was 6mm with sluggish and 7mm with fixated pupil before surgery showed no improvement in vision. Patients with some response to direct reflex or contralateral indirect reflex testing preoperative showed vision improvement postoperative. Direct and indirect pupillary reflexes can be important factors determining treatment for TON. In unconscious patients with a fracture involving the optic canal, timely surgical intervention based on pupillary reflex can prevent permanent loss of vision.

Endoscopic Extended Transsphenoidal Surgery for Transbasal Tuberculum Sellae Meningioma: 2-Dimensional Operative Video.

Transbasal meningiomas1 are a rare group of tumors that grow intracranially, invade the skull base, and propagate extracranially; they are usually located at the level of the olfactory cribra and sphenoid wing.1-4 Transbasal tuberculum sellae meningiomas are a subset of these tumors, which extend into the suprasellar and sphenoid regions. The traditional transcranial approach for some transbasal meningiomas has recently evolved toward the transnasal endoscopic approach, which allows the removal of both the intranasal and intracranial components, reducing the manipulation of the optic nerves and neurovascular structures. Nevertheless, specific anatomical criteria must be present; the knowledge of specific anatomy5,6 and the surgeon's experience are fundamental for reaching the most favorable outcome.7-11 In this video, we present the case of a 50-year-old woman with a history of progressive visual impairment and scotoma in the left inferotemporal quadrant. Radiological examinations suggested a transbasal tuberculum meningioma that extended into the suprasellar region, sphenoid sinus, and optic canals. An endoscopic transtuberculum approach with intraoperative visual-evoked potentials12 was performed, allowing an early devascularization with the preservation of the superior hypophyseal arteries and the removal of the component extending in the medial portion of both optic canals. The postoperative MRI documented a gross total resection without complications. The patient reported an immediate improvement of the visual symptoms. Histopathology documented a meningioma (CNS World Health Organization grade 1) with bone invasion. The patient consented to the procedure and to the publication of her image; Institutional Review Board approval was not required for this single case report.

Morphology, pneumatization, septation, and protrusion of nearby structures into the sphenoid sinus: A retrospective radiological study

The morphology of the sphenoid sinus is critical in planning endoscopic sinus surgery, pituitary gland surgery, cerebrospinal fluid leak repair, the management of chronic sphenoid sinusitis, and the evaluation of skull base tumours. The objective of this study was to evaluate the morphology of the sphenoid sinus, with an emphasis on classification, septation, protrusion of structures, and dehiscence of the bony covering. In this retrospective radiological study, the morphology of the sphenoid sinus was analysed using 400 computed tomography scans. According to Hamberger’s classification, the sphenoid sinus was classified into postsellar and presellar varieties. Additionally, the extent of pneumatization of the pterygoid process, anterior clinoid process, and greater wing of the sphenoid was noted. The anteroposterior, transverse, and vertical diameters of the sphenoid sinus were also measured. The relative positions of the genu of the internal carotid artery, vidian canal, and intracanalicular optic nerve were also recorded. The mean anteroposterior length, transverse length, and vertical length of the sphenoid sinus were found to be 29.3 (±2.8), 31.9 (±2.7), and 22.8 (±1.9) mm, respectively. The sellar type was found in 90% of subjects, while the remaining 10% had the presellar type. Only two subjects had the concha type of sinus. A single septum was noted in 32% of cases.Pneumatization of the pterygoid process was found in 22.5%, the anterior clinoid process in 27%, and the greater wing of the sphenoid in 21.25%. Optic nerve protrusion occurred in 24.5% of cases, and 23% of optic canals were dehiscent. The findings of this study hold significant relevance for neurosurgery, particularly in procedures involving the skull base, such as transsphenoidal surgery and optic nerve decompression

Morphological and Morphometric Study of the Pterion – A Cadaveric Study in Sri Lanka

Introduction: Pterion is an important landmark as its relation to the anterior branch of middle meningeal artery, Broca’s motor speech area on the left side, and surgical interventions relating to pathologies of the sphenoid ridge and optic canal as it provides access to vital structures such as sylvian fissure, circle of Willis, optic nerve, para-sellar regions, middle meningeal vessels and cavernous sinus. Approach through pterion is mostly used to treat lesions of anterior and middle cranial fossa. Pterion ossicle or Epipteric bone are sometimes mistaken as a fracture at this point.Objective: The aim is to study the types of pterions and measure the distance from various bony landmarks on skull to the midpoint of pterion.Methods: Specific measurements were taken, and type of the pterion recorded by two independent investigators in the Frankfurt plane on both sides of 37 adult dry skulls of unknown age, gender and race, without calvaria which were prepared for academic purposes, none of which showed any obvious pathology or trauma. The skulls with broken lateral walls were excluded. The linear distance from the center of the pterion to four anatomical landmarks were measured using a Vernier caliper with an accuracy of 0.1 mm.Results: The sphenoparietal type of pterion was the most common (83.8% left, 81.1% right), followed by the frontotemporal (8.1% left, 13.5% right), and epipteric (8.1% left, 2.7% right) types and the stellate type was the least commonly observed (2.7% left side only). The distances on the left and right sides respectively from the center of the pterion to the frontozygomatic suture were 3.60 ± 0.57 cm and 3.68 ± 0.50 cm, to the zygomatic arch 3.76 ± 0.39 cm and 4.03 ± 0.40 cm, to the tip of the mastoid process 7.96 ± 0.58 cm and 8.16 ± 0.61 cm, and to the topmost part of the external auditory meatus 5.42 ± 0.34 cm and 5.53 ± 0.35 cm.Conclusions: This knowledge is essential in surgical approaches and interventions via the pterion, especially for neurosurgeons while drilling a burr hole at the pterion to prevent orbital penetration due to an anterior drilling and an ineffective access for instrumentation due to a posterior drilling. It will also be helpful for surgeons, radiologists, anthropologists, forensic pathologists in their diagnosis and treatment.

Transmembrane protein 53 craniotubular dysplasia (OMIM # 619727): The skeletal disease and consequent blindness of this new disorder

Craniotubular dysplasia, Ikegawa type (OMIM #619727) denotes the autosomal recessive skeletal disease identified in 2021 featuring blindness acquired in childhood. Five young members of four Indian families harbored a homozygous indel within TMEM53 (OMIM *619722), the gene that encodes transmembrane protein 53 (TMEM53). When intact, TMEM53 spans the nuclear envelope of osteoprogenitor cells, dampens BMP-SMAD signaling, and thereby slows bone formation. Consequently, defective TMEM53 accelerates osteogenesis. Herein, an American boy is compound heterozygous for a novel deletion and a novel missense mutation within TMEM53. His vision and sensorineural hearing became impaired. Radiographic survey revealed diploic thickening of his skull, broad calvarial and facial bones, skeletal modeling errors, vertebral body flattening, wide ribs, and osteopenia of expanded bones. DXA areal bone density (gm/cm2) Z-scores were low. His optic, auditory, and spinal canals were narrow. Mineral metabolism was intact. Serum alkaline phosphatase and osteocalcin levels were normal yet CTX was high. Iliac crest histomorphometry documented accelerated bone formation. His acute vision loss briefly improved following prednisone administration, optic canal decompression, and optic nerve sheath fenestration, but then progressed despite further surgeries and zoledronate treatment aimed to suppress bone turnover. Next generation sequencing of genes associated with elevated skeletal mass, including from high bone turnover, did not suggest an etiology. Whole genome sequencing then revealed within TMEM53: i) a paternally transmitted 54-base deletion, which included the mRNA splice acceptor site for exon 2 as well as 31 bases of exonic sequence (c. 62-23_92del), and ii) a maternally transmitted missense variant (c.650C > T, p.Ser217Leu: NM_024587.4/NP_078863.2) which is extremely rare in gnomAD (frequency = 0.000036), replaces Ser217 highly conserved across species, and is scored as damaging by SIFT and Mutation Taster. We call this new osteopathy TMEM53 craniotubular dysplasia.

Computed tomography based evaluation of the association between sphenoid sinus pneumatization patterns and variations of adjacent bony structures in relation to age and gender

Many studies revealed that the sphenoid sinus pneumatization (SSP) affects the protrusion/dehiscence of adjacent structures including optic canal (OC), foramen rotundum (FR), vidian canal (VC), and carotid canal (CC). Knowledge of this relationship bears vital importance to identify the safest surgical route during transsphenoidal procedures. Therefore, we aimed to determine the individualized prevalence of the protrusion/dehiscence of adjacent structures based on sagittal and coronal SSP (SSSP and CSSP) patterns. Computed tomography images of 300 patients were analysed to identify the SSSP and CSSP types, and the protrusion/dehiscence of adjacent structures was determined. The relationship between the variables was examined using statistical analysis in terms of age, gender, and laterality. The most prevalent SSSP type was postsellar (62.7%), followed by sellar (30%), presellar (6.6%), and conchal (0.7%). In 71.3% of patients, five types of CSSP were observed, with 23.6% and 21.7% exhibiting Type IV and V, respectively. Our results indicated that postsellar type, Type IV and V CSSP associated with the highest likelihood of protrusion/dehiscence of OC, FR, VC, and CC. Furthermore, no significant correlation was observed between these qualitative variables and gender, with the exception of the VC dehiscence, the protrusion of OC and CC. No notable differences were identified with respect to laterality. Also, the probability of having postsellar type, Type IV and V CSSP, as well as the protrusion of OC, VC, and CC, decreased with increasing age. Further detailed analysis of this association is required to predict the size of the surgical window and to prevent neurovascular injury.

Clinical characteristics of peripapillary hyperreflective ovoid mass-like structures in myopic children.

To describe the characteristics of peripapillary hyperreflective ovoid mass-like structure (PHOMS) in myopic children and to investigate factors associated with PHOMS. This retrospective observational study included 101 eyes of 101 children (age ≤17y) with myopia. All included patients underwent comprehensive clinical examination. Optic nerve canal parameters, including disc diameter, optic nerve head (ONH) tilt angle, and border tissue angle were measured using serial enhanced-depth imaging spectral-domain optical coherence tomography (EDI-OCT). Based on the optic disc drusen consortium's definition of PHOMS, eyes were classified as PHOMS group and non-PHOMS group. PHOMS was categorized according to height. Sixty-seven (66.3%) eyes were found with PHOMS. Small PHOMS could only be detected by optical coherence tomography (OCT). Medium PHOMS could be seen with blurred optic disc borders corresponding to OCT. The most frequent location of PHOMS was at the nasosuperior (91%, 61 of 67 eyes) to ONH disc. The axial length and spherical equivalent were more myopic in the PHOMS group than in the non-PHOMS group (both P<0.001). ONH tilt angle was also significantly greater in PHOMS group than in non-PHOMS group [8.90 (7.16-10.54) vs 3.93 (3.09-5.25), P<0.001]. Border tissue angle was significantly smaller in PHOMS group than in non-PHOMS group [29.70 (20.90-43.81) vs 45.62 (35.18-60.45), P<0.001]. In the multivariable analysis, spherical equivalent (OR=3.246, 95%CI=1.209-8.718, P=0.019) and ONH tilt angle (OR=3.275, 95%CI=1.422-7.542, P=0.005) were significantly correlated with PHOMS. There was no disc diameter associated with PHOMS. In the linear regression analysis, border tissue angle was negatively associated with PHOMS height (β=-2.227, P<0.001). PHOMS is associated with optic disc tilt and optic disc nasal shift in myopia. Disc diameter is not a risk factor for PHOMS. The changes in ONH caused by axial elongation facilitated an understanding of the mechanism of PHOMS.