History of Haller and Onodi Cells.

This study aimed to evaluate multiple anatomical and morphological factors influencing the localization of the sphenoid sinus ostium (SSO) to improve surgical safety in endoscopic sinus surgery. Computed tomography (CT) images of 302 subjects were examined. The vertical and horizontal positions of the SSO were assessed using standardized reference lines on sagittal and axial sections. Pneumatization patterns were classified on sagittal and coronal planes. Rostrum pneumatization and the presence of Onodi cells were also evaluated. Morphometric measurements and potential influencing factors were analyzed using logistic and linear regression models. The SSO was most frequently located in the superior (72.8%) and medial (55.6%) thirds. The female gender increased the likelihood of medial ostium localization by 2.715-fold. Compared to the sellar type, conchal pneumatization increased the probability of medial positioning by 9.82-fold, while the postsellar type reduced it (OR: 0.208). The postrotundum type was strongly associated with superior and medial localizations (OR: 3.289 and OR: 2.978, respectively). A wider sphenoid rostrum reduced the probability of medial localization, whereas rostrum pneumatization promoted superior displacement of the SSO. Onodi cells and increased sinus height shifted the SSO inferiorly by 1.929 and 0.341 units, respectively. The localization of the SSO was found to be significantly influenced by gender, sphenoid sinus pneumatization patterns, rostrum morphology, and the presence of Onodi cells. Careful preoperative evaluation of CT images for these factors may provide valuable insights for surgeons and help minimize the risk of serious complications during endoscopic sinus surgery.

Abstract The nasal cavity and paranasal sinuses form an anatomically intricate and highly variable region that plays a vital role in the physiological functions of the upper respiratory tract and is intimately associated with a wide range of pathological and surgical considerations. Anatomical variations in this area – such as concha bullosa, septal deviation, Haller and Onodi cells – are frequently linked to impaired mucociliary clearance, obstruction of natural drainage pathways, and an increased risk for the development of chronic rhino-sinusitis. Moreover, the presence of such variations significantly influences the planning and execution of functional endoscopic sinus surgery (FESS) and transnasal approaches to the skull base, increasing the likelihood of complications involving the optic nerve, internal carotid artery, or orbital structures. This review aims to provide a structured analysis of the most clinically relevant anatomical variants of the nasal cavity and paranasal sinuses, grounded in contemporary literature from the past decade across radiological imaging, anatomical studies, and skull base surgery. It explores the relationship between structural anomalies and the frequency and severity of sinonasal pathology, as well as their implications for endoscopic surgical practice. Special attention is given to surgical hazards posed by variations such as dehiscent lamina papyracea, accessory maxillary ostia, and pneumatization of the anterior clinoid process. The review includes tabular and graphical representations illustrating the associations between specific anatomical features and their related clinical and surgical risks. This integrative approach is intended to support clinicians in enhancing diagnostic accuracy, optimizing preoperative planning, and minimizing intra-operative complications through a personalized anatomical understanding of this region.

Objectives:Ethmoidal air cell variants such as Agger nasi, Haller, Onodi, uncinate, and ethmoid bullae are critical anatomical structures influencing the outcomes of functional endoscopic sinus surgery (FESS). This study evaluated their prevalence and gender-specific distribution in a Sangli, Maharashtra, India, via cone beam computed tomography (CBCT).Materials and Methods:A cross-sectional retrospective analysis of 258 CBCT scans (150 males, 108 females; ages 18–65) was conducted. The presence of five defined ethmoidal variations was recorded (absent/unilateral/bilateral). Two radiologists independently assessed images; disagreements were resolved by consensus. Statistical significance in gender distribution was tested via the Chi-square test (P < 0.05 considered significant).Results:Onodi cells were observed in 96 cases (32%), Haller in 53 (17.7%), Agger nasi in 31 (10.3%), uncinate bulla in 8 (2.7%), and prominent ethmoid bulla in 5 (1.7%). Gender distribution showed male predominance in all variants except uncinate bulla, but none achieved statistical significance (P > 0.05).Conclusions:Onodi and Haller cells exhibit high prevalence, emphasizing the necessity for thorough pre-FESS CBCT evaluation. Despite non-significant gender differences, these variations should be carefully assessed in individual patients. The findings support the role of personalized radiological analysis to reduce surgical risks.

Objective: To compare the anatomical differences of the sphenoid sinus and adjacent critical structures between patients with hormone-producing pituitary tumors, distinguishing between acromegalic and non-acromegalic groups, to optimize surgical planning and anticipate potential complications.Material and Methods: A retrospective analysis was conducted on 150 patients diagnosed with hormone-secreting pituitary adenomas (50 acromegalic and 100 non-acromegalic) treated at the Neurosurgery Outpatient Clinic, Songklanagarind Hospital, between January 1, 2012 and December 31, 2022. Patient demographics and sphenoid sinus anatomical characteristics were assessed using computed tomography (CT) scans in collaboration with radiologists. Statistical analysis was performed using the R program with a significance threshold of p-value&lt;0.05.Results: Acromegalic patients exhibited significantly higher rates of post-sellar sphenoid pneumatization (p-value=0.002), sphenoid septum attachment to the optic nerve (p-value=0.018), and Onodi cells (p-value=0.011). The distance between the sphenoid rostrum and Vidian canal was significantly greater in acromegalic patients (p-value&lt;0.001 right side, p-value=0.008 left side). Additionally, acromegalic patients had higher incidences of Vidian nerve protrusion (p-value=0.013), optic nerve protrusion (p-value&lt;0.001), optic nerve dehiscence (p-value=0.025), and internal carotid artery (ICA) dehiscence (p-value=0.034). The intercarotid distance was significantly narrower in acromegalic patients (mean 16.4 mm, p-value&lt;0.001).Conclusion: Patients with acromegaly and hormone-secreting pituitary adenomas demonstrate distinct anatomical variations in the sphenoid sinus and adjacent structures compared to non-acromegalic patients. These differences underscore the necessity for thorough preoperative evaluation and meticulous surgical planning to minimize risks during transsphenoidal pituitary surgery.

We aimed to determine paranasal sinus volumes using 3D volumetric measurements and to evaluate the effect of anatomical variations on these volumes, ensuring balanced age and sex distribution during childhood. Thirteen age groups (0-16 years), each including 10 males and 10 females, were formed. After excluding sinus pathologies, a total of 260 subjects were randomly selected from CT head examinations. Right and left frontal, maxillary, and sphenoid sinus volumes were calculated using 3D Slicer software (version 5.6.2) following manual segmentation of axial CT slices. Also, the presence of right and left Agger Nasi cells, Haller cells, Onodi cells, and concha bullosa were recorded. No significant difference was found between males and females in sinus volumes (p > 0.05). Mean right and left maxillary sinus volumes were 6.23 cm3 and 6.27 cm3 (p = 0.551); frontal sinuses were 0.79 cm3 and 0.86 cm3 (p = 0.170); and sphenoid sinuses were 1.64 cm3 and 1.85 cm3 (p = 0.041). Sphenoid sinus pneumatization appeared in 30% of the 0-6-month group and in over 75% of older groups. Frontal pneumatization began at age 2-3 and exceeded 50% after age 4. Agger Nasi, Haller, Onodi cells, and concha bullosa were detected in 58.8%, 31.2%, 10%, and 22.3% of cases, respectively. Anatomical variations showed no significant effect on sinus volumes (p > 0.05). We developed a paranasal sinus volume chart applicable to routine practice, showing that anatomical variations had no significant impact on the development. This is the first study to investigate the impact of anatomical variations on sinus development and volume, along with the age at which variations emerge, with a balanced distribution of age and sex.

Background: Chronic rhinosinusitis (CRS) is a common inflammatory condition of the nasal cavity and paranasal sinuses persisting for more than 12 weeks and causing significant morbidity worldwide. Accurate diagnosis and precise delineation of disease extent are essential for effective management. With the advent of Functional Endoscopic Sinus Surgery (FESS), diagnostic nasal endoscopy and computed tomography (CT) of paranasal sinuses have become integral to preoperative evaluation. However, discrepancies between radiological findings and intraoperative observations still exist, particularly regarding anatomical variations and sinus involvement. Establishing a correlation between clinical, radiological, and operative findings is therefore crucial to optimize surgical planning and outcomes. Material and Methods: This prospective observational study was conducted in the Department of Otorhinolaryngology at a tertiary care teaching hospital in Western India between May 2023 and August 2024. A total of 42 patients diagnosed with chronic rhinosinusitis and planned for endoscopic sinus surgery were included. All patients underwent detailed clinical evaluation, diagnostic nasal endoscopy, and CT scan of paranasal sinuses prior to surgery. CT findings were compared with intraoperative observations to assess diagnostic accuracy. Sensitivity, specificity, accuracy, and Cohen’s kappa coefficient were calculated to evaluate agreement between CT and operative findings. Results: Among the 42 patients, males predominated (54.76%), with the most affected age group being 31–40 years. Nasal obstruction was the most common symptom (92.85%). Maxillary sinus was the most frequently involved sinus on CT, followed by ethmoid sinuses. CT scan demonstrated high sensitivity for detecting sinus disease and osteomeatal complex obstruction, with substantial agreement for osteomeatal complex blockage and deviated nasal septum. However, lower sensitivity and agreement were observed for certain anatomical variations such as concha bullosa and Onodi cells. Conclusion: CT scan of paranasal sinuses is a highly sensitive tool for evaluating CRS and guiding surgical management. When combined with clinical assessment and nasal endoscopy, it provides optimal preoperative planning and improves intraoperative safety

Background:Anatomical variations of the nasal cavity and ethmoidal complex, though often asymptomatic, may influence nasal airflow, sinus drainage, and the development of sinonasal disorders. Accurate imaging is crucial for diagnosis and surgical planning. This study aimed to assess the prevalence and types of anatomical changes in the nasal cavity and ethmoidal complex using cone-beam computed tomography (CBCT).Materials and Methods:A cross-sectional observational study was undertaken with 300 adult patients’ CBCT scans. Variations examined included septal deviation, concha bullosa, enlarged Nasi cells, Haller cells, Onodi cells, and anomalies of the uncinate process and turbinates.Results:Nasal septal variations were found in 56% of patients, with single deviations (18.3%) and deviation with spurring (11.0%) being the most common. Concha bullosa was most common in the middle turbinate (88.7% right, 91.3% left), with the lamellar subtype predominate. In 94.0% of instances, inferior turbinate hypertrophy was seen, with Onodi cells accounting for 32.0% of ethmoidal air cells. Other variations were Haller cells (17.7%) and Aggre Nasi cells (10.3%).Conclusion:It was concluded that anatomical differences in the nasal cavity and ethmoidal complex are widespread and have therapeutic implications. In otolaryngology and maxillofacial practice, CBCT is an invaluable imaging tool for detailed assessment, improving diagnostic accuracy, and assisting with surgical planning.

Background: The sphenoid sinus is essential for transsphenoidal surgical accesses to the sellar and parasellar regions because of its anatomic proximity to vital vascular and neurologic structures such as the internal carotid artery, optic nerve, and cavernous sinus. The high degree of morphological variability of the sphenoid sinus has a significant impact on surgical technique and the risk of intraoperative complications. Detailed knowledge of individual anatomy is therefore crucial for the safety and efficacy of transsphenoidal approaches. Objectives: This review aims to conduct a systematic analysis of the current scientific literature on anatomical variations in the sphenoid sinus and their clinical relevance in surgical interventions to the skull base. Special attention is paid to the influence of morphological features on surgical strategies to pathological processes in this area and postoperative outcomes. Materials and Methods: A systematic review of the literature was conducted according to PRISMA 2020 guidelines. The PubMed, Scopus, Web of Science, and Google Scholar databases were searched for the period March 2010 to March 2025. Keywords such as "sphenoid sinus", "anatomical variations", "transsphenoidal surgery" and "skull base" were used. Original studies, systematic reviews, and meta-analyses focused on the anatomy, pneumatization, and surgical significance of sphenoid sinus variations are included. Quality and relevance criteria for published material were considered in the selection of articles. Results: The most commonly identified anatomic variations included sellar and lateral pneumaticity, the presence of Onodi cells, multiple and deviated septa, and dehiscence of the posterior wall of the sphenoid sinus and prolapse into its cavity of the internal carotid artery. These variations are associated with an increased risk of intraoperative vascular injury, visual deficit, and postoperative liquorrhea. Accurate preoperative assessment by high-resolution computed axial tomography and magnetic resonance imaging, as well as the use of intraoperative neuronavigation, are critical to reduce surgical risk. Conclusions: Anatomic variations in the sphenoid sinus are an essential factor to consider when planning and performing transsphenoidal surgical accesses. An individualized approach based on detailed diagnostic imaging analysis and neuronavigation technologies contributes to a higher safety of the performed surgical interventions, a better radicality of tumor resection and more favorable postoperative outcomes.

Abstract Background Onodi cells (OCs) are clinically significant for a rhinologist owing to their close relationship with the internal carotid artery and optic nerve, enclosing the optic canal. Therefore, pathologies affecting the OC can result in harmful ophthalmologic complications. Optic neuritis resulting from a mucocele within the Onodi cell is a rare condition, and with fewer than thirty cases reported since 1997, and most reports are in the Asian region. Case presentation Here, a 29-year-old man presented with left optic neuropathy attributable to compression from an expanded onodi cell mucocele, which is a rare entity. He underwent endoscopic marsupialization of the mucocele, with subsequent visual acuity improvement from counting fingers at seventy cm to 6/60 uncorrected visual acuity (UCVA) and no recurrence. Conclusion Although Onodi cell mucocele is rare, it should be considered when diagnosing unexplained unilateral vision loss.

<strong>Objective:</strong> This study aimed to evaluate the presence and volume of the Onodi cell (OC) and to investigate its anatomical relationship with surgically important neighbouring structures such as the optic canal (OCa), internal carotid canal (CC), and vidian canal (VC), focusing on canal types and bony dehiscence. <strong>Materials and Methods:</strong> High-resolution computed tomography (CT) scans of 110 patients were analysed, with 220 sphenoid sinus sides evaluated. Onodi cells were identified and classified based on their location. Their volumes were measured using manual segmentation in the OSIRIX software. The types of OCa, CC, and VC, as well as the presence or absence of bony dehiscence in these canals, were radiologically assessed. Statistical analyses were performed to evaluate the relationships between the OC volume, canal configurations and dehiscence status. <strong>Results: </strong>The OC was present in 30% of cases. Its presence was significantly associated with higher-risk OCa types (Types 3 and 4) and with optic nerve dehiscence. Onodi cell volume was significantly greater in patients with type 3 OCa and type 3 CC. Internal carotid artery and VC dehiscence were also more common in cases with larger OC volumes. <strong>Conclusion:</strong> This study is one of the few to quantitatively assess OC volume and its associations with nearby critical neurovascular structures. The findings emphasise that both the presence and size of the OC are important anatomical considerations that should be carefully evaluated preoperatively using high resolution CT to reduce the risk of complications in endoscopic sinus surgery.

The study aimed to evaluate the prevalence of extramural expansion of posterior ethmoid cells using Cone beam computed tomography (CBCT), as well as to propose anatomical criteria and a classification system for Onodi cells based on their spatial relationship with the sphenoid sinus. Cone beam computed tomography (CBCT) scans of 513 ENT (Ear, Nose, and Throat) and dental patients of outpatient clinics, 199 men and 314 women, mean age 36 ± 13 years (range: 18-84 years). Several extramural variants of posterior ethmoid (PE) cells were examined, such as sphenoethmoidal cells (where PE cells extend into the sphenoid sinus) and posterior ethmomaxillary cells (characterized by extension into the maxillary sinus). Among sphenoethmoidal cells, the following subtypes were identified: Onodi cells (PE cell extension toward the optic canal), inferolateral sphenoethmoidal cells (inferolateral expansion of PE cells relative to the sphenoid sinus without reaching the optic canal), and supraseptal posterior ethmoid cells (migration of PE cells into the region between the nasal septum and the cribriform plate). Among 513 patients examined, sphenoethmoidal cells were identified in 66 cases (89 cells), demonstrating considerable anatomical diversity. We observed a spectrum of variants that included predominant Onodi cell types (superior [48.2%], superolateral [19.2%], and lateral [18%]), less frequent Onodi forms (superoposterior [11.3%] and intersphenoidal [1.1%]), as well as other sphenoethmoidal variants such as supraseptal and inferolateral cells. Based on the data obtained, we introduce an updated classification of Onodi cells that accounts for their spatial relationship with surrounding structures. Posterior extramural ethmoid cells may pneumatize the sphenoid bone to such an extent that they can be radiologically mistaken for the sphenoid sinus. Accurate differentiation between these structures is crucial, as inflammatory processes may develop independently within either the sphenoid sinus or the sphenoethmoidal cells. Misidentification may lead to inappropriate treatment strategies. Therefore, precise radiological assessment is essential to determine the true origin of inflammation and ensure targeted, effective clinical management.

Background: This study aims to evaluate the prevalence of anatomical variations in the paranasal sinus (PNS) region and assess their clinical relevance, particularly concerning sinusitis and surgical implications, using Multidetector Computed Tomography (MDCT).Methods: A prospective observational study was conducted over one year in the Department of Radiodiagnosis, NRI Institute of Medical Sciences, Visakhapatnam, Andhra Pradesh, India.A total of 142 adult patients (73 females and 69 males; mean age 34.2 years) referred for MDCT of PNS for suspected sinus pathology were included.Axial scans (0.625 mm slice thickness) and coronal reconstructions were analysed for anatomical variants and mucosal abnormalities, following standard protocols.Results: Anatomical variations were identified in 124 patients (87.3%).The most prevalent were deviated nasal septum (54.3%) and middle concha bullosa (46.5%).Other variations included paradoxical middle turbinate (13.4%),Haller cells (7%), and Onodi cells (2%).Mucosal abnormalities suggestive of sinusitis were observed in 94 patients (66%).Variants were present in 77.5% of those with sinusitis and 87.5% of those without.Maxillary sinusitis was most common (49%).High-risk variations such as dehiscent optic nerve (Type II/III: 7-10%) and asymmetric ethmoid roofs (Keros Type II: 78.9%) were noted.Conclusion: Anatomical variants in the PNS are common but do not inherently cause sinusitis.However, recognizing them is critical for surgical safety in Functional Endoscopic Sinus Surgery (FESS).Preoperative MDCT serves as an essential tool in minimizing complications and optimizing surgical outcomes.

Conventional radiography has been largely replaced by high-resolution CT scan of the paranasal sinuses (PNS) for evaluating congenital anatomical variations and sinus pathologies (1-3). In this retrospective study, we evaluated 1,450 CT scans of the paranasal sinuses to determine the prevalence of various anatomical variations. Patients aged 15 to 85 years were included, while those with bone destruction or distortion due to surgery, trauma, or other pathologies were excluded. The most common variation observed was a deviated nasal septum (DNS) in 603 cases (41.6%), followed by Agger nasi cells in 548 cases (37.8%), concha bullosa in 302 cases (20.8%), bony nasal spur in 181 cases (12.5%), hypoplastic frontal sinus in 116 cases (8.0%), Haller cells in 44 cases (3.0%), Onodi cells in 29 cases (2.0%), pneumatization of the vomer bone in 15 cases (1.0%), and septate maxillary sinus in 12 cases (0.8%).

The ethmoid and sphenoid sinuses exhibit marked anatomical variability that can impact surgical approaches and predispose individuals to complications during sinus and skull base procedures. To characterize the morphometric patterns and anatomical variants of the ethmoid and sphenoid sinuses based on high-resolution CT data and to analyze their surgical and clinical significance. A total of 400 CT scans were analyzed. Sinuses were classified by pneumatization type, dimensions, and presence of anatomical variants. 3D reconstructions were performed to assess spatial orientation and proximity to neurovascular structures. Ethmoid sinus complexity was classified into three distinct types, with higher complexity correlating with narrower surgical corridors and increased risk of incomplete ethmoidectomy. Sphenoid pneumatization showed significant variability, including presellar, sellar, and postsellar types. Onodi cells were identified in 13% of cases, closely related to the optic canal. Septated sphenoids were present in 21%, often traversing the internal carotid artery canal. Detailed anatomical understanding of posterior sinus morphology and variation is essential for safe and effective sinus and skull base surgery. This study provides a morphometric atlas to support individualized surgical planning.

Background: Sphenoiditis poses diagnostic and treatment challenges due to its complex anatomy and potential for serious complications. Anatomic variations, such as Onodi cells, could play a role in the onset and spreading of inflammation. The diagnosis and treatment of sphenoiditis can be more difficult if Onodi cells are present, especially due to their proximity to delicate vital tissues. Objectives: The purpose of this study was to look at the frequency, features, and relationship between Onodi cells and sphenoiditis. Methods: This multicentric study comprised 550 people who received sinonasal CT imaging. The Thimmaiah classification was used to assess the presence and features of Onodi cells, and radiographic results were used to diagnose sphenoiditis. We conducted univariate and multivariate logistic regression to evaluate the relationships between sphenoiditis and Onodi cells. Results: The prevalence of Onodi cells was 32.40%, with a higher prevalence on the right side (18.40%) compared to the left side (8.40%). The multivariable analysis revealed a significant correlation between right-side Type II Onodi cells and a higher incidence of sphenoiditis (OR = 6.81, 95% CI: 1.14-38.97, p = 0.029). In the univariable analysis (OR = 3.00, 95% CI: 1.15-6.96, p = 0.015), but not in the multivariable analysis, the presence of Type I Onodi cells on the left side was significantly associated with sphenoiditis. Conclusions: There may be a link between a higher incidence of sphenoiditis and the presence of Type II Onodi cells on the right side. In order to validate these findings and clarify the underlying processes of this connection, more prospective research is required.

Background and objective Anatomical variations of the paranasal sinuses influence sinus drainage and airflow, contributing to chronic rhinosinusitis. This study aimed to assessthe prevalence of these variations and their association with sinus infections by using CT findings. Methods A retrospective CT-based analysis of75 patients(aged 25-70 years) was conducted. Anatomical variations, includingnasal septal deviation (NSD), concha bullosa, agger nasi cells, Haller cells, and Onodi cells, were recorded. The association between these variations and affected sinuses was analyzed using the chi-squared test and Fisher's exact test; a p-value <0.05 was considered statistically significant. Results NSD was the most common anatomical variation, observed in50 patients (66.6%), followed by hypertrophic ethmoidal bulla in 35 (46.6%), and concha bullosa in 30 (40%).Among the affected sinuses, maxillary sinusitis was the most frequently observed, affecting60 patients (80%), followed byfrontal in 45 (60%),ethmoidal in 30 (40%), andsphenoid sinusitis in eight (10.6%). Significant associations were found betweenNSD, concha bullosa, and maxillary sinusitis; agger nasi cells with frontal/ethmoid sinusitis;Haller cells with maxillary sinusitis; andOnodi cells with sphenoid sinusitis (p<0.05). Conclusions Paranasal anatomical variations significantly correlate with sinusitis, emphasizing theimportance of preoperative CT evaluationin guiding medical and surgical management. Recognizing these variations enhances diagnostic accuracy and improves surgical outcomes infunctional endoscopic sinus surgery (FESS).

Chronic rhinosinusitis (CRS) is frequently associated with anatomical variations that may predispose individuals to impaired sinus drainage and mucosal inflammation. Computed tomography (CT) of the paranasal sinuses provides an essential diagnostic tool for evaluating these variations. To assess the prevalence and types of anatomical variations in patients with CRS using CT Data. A retrospective cross-sectional study was conducted on 75 patients diagnosed with CRS. CT scans were evaluated for anatomical variations including concha bullosa, deviated nasal septum, agger nasi cells, Haller cells, Onodi cells, uncinate process variations, and paradoxical middle turbinate. The most frequent variation observed was concha bullosa (64%), followed by deviated nasal septum (61.3%), agger nasi cells (49.3%), and Haller cells (32%). Onodi cells were observed in 21.3% of patients, uncinate process variations in 17.3%, and paradoxical middle turbinate in 12%. Anatomical variations are common in CRS patients and can play a critical role in the pathophysiology of the disease. CT imaging is vital in identifying these variations, which can guide appropriate surgical planning.

Introduction: Functional Endoscopic Sinus Surgery (FESS) has popularly been used for the effective treatment of paranasal sinus disorders and for the removal of tissue obstructing the osteo meatal complex and the facilitation of drainage. However, almost 16% to 50% of all the complications of the FESS have orbital involvement. The complications are due to the wide variation in the anatomy of the sphenoidal and posterior ethmoidal sinuses. This study aimed to find the prevalence of types of relationships that optic nerves have with the sphenoid sinus and also the prevalence of anatomical variation in sphenoid sinus. Methods: This is the descriptive cross-sectional study conducted over 210 participants appearing for CT scan imaging of paranasal sinuses. CT scan of paranasal sinus was performed with 5 mm thickness and then reconstructed to 1.5 mm thickness and evaluated to find the relationship of optic nerve with the paranasal sinuses according to Delano et al. classification. Prevalence of Onodi cells and anterior clinoid process pneumatization was also evaluated for variation in sphenoid sinus. Results: This study found that bilateral optic nerve of Type-I was found in 82.38% people followed by Type-IV in 14.29%. While, Type-III was completely absent in the study population. Prevalence of Onodi cells was 10.95% and that of ACP pneumatization was 6.67%. Conclusions: Variation in relationship of Optic Nerve with paranasal sinuses found with Type-I being the most common.

Compressive optic neuropathy caused by Onodi cell-associated mucocele is a rare complication with only a few cases reported in the literature. We describe a new case of Onodi cell mucocele in a 32-year-old woman who presented with progressive blurring of vision and pain in her right eye. CT and MRI were diagnostic of an Onodi cell mucocele. She underwent endoscopic sinus surgery 12 days after the onset of symptoms, and follow-up revealed improvement in symptoms.