Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2024 Feb;44(1):36-41.
doi: 10.14639/0392-100X-N2462. Epub 2023 Dec 29.

Type IV optic nerve and Onodi cell: is there a risk of injury during sphenoid sinus surgery?

Gian Luca Fadda  1 , Anastasia Urbanelli  1 , Alessio Petrelli  2 , Marta Trossarello  1 , Letizia Nitro  3 , Alberto Maria Saibene  3 , Eugenio De Corso  4 , Dario Gned  5 , Marco Panfili  6 , Giovanni Cavallo  1
Affiliations

Type IV optic nerve and Onodi cell: is there a risk of injury during sphenoid sinus surgery?

Gian Luca Fadda et al. Acta Otorhinolaryngol Ital. 2024 Feb.

Abstract

Objective: This study aims to determine the prevalence and types of Onodi cells through computed tomography and investigate the relationship between Onodi cell and the surrounding structures, paying particular attention to the risky proximity to the optic nerve canal.

Methods: In this study, 430 computed tomography scans of paranasal sinuses were analysed to establish the prevalence and different types of Onodi cells. Furthermore, the relationship between Onodi cell and different patterns of sphenoid sinus pneumatisation and surrounding structures were investigated. Special attention was paid to the relationship between Onodi cell and the optic nerve canal, particularly in cases when the optic nerve canal was bulging by more than 50% into the Onodi cell (Type IV).

Results: The Onodi cell was detected in 21.6% of cases, with the most common being Type I (48.5% right, 54.3% left). Type IV bulging of the optic nerve canal into the Onodi cell was observed in 47.1% of cases on the right side, 41.2% on the left side and bilateral in 11.7% of cases.

Conclusions: In our series, we observed a high prevalence of Type IV optic nerve bulging into the Onodi cell. For this reason, we suggest that clinicians should always try to identify it in a pre-operative setting with computed tomography to avoid catastrophic consequences during endoscopic sinus surgery approaching the sphenoid area.

Keywords: Onodi cell; computed tomography; endoscopic sinus surgery; optic nerve; sphenoid sinus.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

This research did not receive any specific grant from fund-ing agencies in the public, commercial, or not-for-profit sectors.

Figures

Figure 1.
Figure 1.
Onodi cell (*) Type I pattern of pneumatisation is above and medial to the horizontal line. (1a) Coronal, (1b) Axial and (1c) Sagittal, paranasal CT scan. A horizontal line was drawn at the uppermost part of the sphenoid sinus (s) in the coronal image (1a). Optic canals (white arrows) with bulging > 5 mm (Type IV) are shown.
Figure 2.
Figure 2.
Onodi cell (*) Type II is above and below the horizontal line. Axial (2b) CT image showing protrusion of ICA (double arrow). (2a) Coronal, (2b) Axial and (2c) Sagittal, paranasal CT scan. A horizontal line was drawn at the uppermost part of the sphenoid sinus (s) in the coronal image (2a). Optic canals (white arrows) with bulging > 5 mm (Type IV) are shown.
Figure 3.
Figure 3.
Onodi cell (*) Type III is below the horizontal line. (3d) Endoscopic right sphenoid sinus, Onodi cell and optic canal are shown. (3a) Coronal, (3b) Axial and (3c) Sagittal, paranasal CT scan. A horizontal line was drawn at the uppermost part of the sphenoid sinus (s) in the coronal image (3a). Optic canals (white arrows) with bulging > 5 mm (Type IV) are shown.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Onodi A. The optic nerve and the accessory sinuses of the nose. Der Sehnerv and die NebenOhlen der Nase. Wien, Germany: Alfred Holder; 1907. pp. 1-6.
    1. Özdemir A, Bayar Muluk N, Asal N, et al. . Is there a relationship between Onodi cell and optic canal? Eur Arch Otorhinolaryngol 2019;276:1057-1064. https://doi.org/10.1007/s00405-019-05284-0 10.1007/s00405-019-05284-0 - DOI - PubMed
    1. Ali IK, Sansare K, Karjodkar F, et al. . Imaging analysis of Onodi cells on cone-beam computed tomography. Int Arch Otorhinolaryngol 2020;24:E319-E322. https://doi.org/10.1055/s-0039-1698779 10.1055/s-0039-1698779 - DOI - PMC - PubMed
    1. Chmielik LP, Chmielik A. The prevalence of the Onodi cell – most suitable method of CT evaluation in its detection. Int J Pediatr Otorhinolaryngol 2017;97:202-205. https://doi.org/10.1016/j.ijporl.2017.04.001 10.1016/j.ijporl.2017.04.001 - DOI - PubMed
    1. Driben JS, Bolger WE, Robles HA, et al. . The reliability of computerized tomographic detection of the Onodi (Sphenoethmoid) cell. Am J Rhinol 1998;12:105-111. https://doi.org/10.2500/105065898781390325 10.2500/105065898781390325 - DOI - PubMed