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

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.

Nasal Cytology Changes in Head and Neck Cancer Treatment: A Systemic Review.

Nasal cytology is a non-invasive, low-cost exam that can help physicians in the diagnosis of allergic and nonallergic rhinitis, discriminating between different nasal disorders. The aim of this review is to summarize and analyze the current knowledge about nasal cytological examination in head and neck cancer, with a specific focus on the effects of different treatments. Indeed, nasal cytology is important to choose the best treatment for nasal complaints in each patient. A review of the English literature (PubMed, Scopus, Cochrane) was performed (5404 records screened). The inclusion criteria were clinical trials, cohort studies, case-control studies, case series, and case reports regarding nasal cytology in head and neck cancer treatment. Exclusion criteria were as follows: non-human studies, non-English literature, non-cytological evaluations. Two independent reviewers, working separately, extracted the data from all the eligible studies, which were subsequently cross-checked. Five studies were included in qualitative synthesis: three assessed mucosal disorders after radiation therapy and two after total laryngectomy. Radiotherapy can determine mucous or squamous cell metaplasia and neutrophil inflammation. Laryngectomees show hyperplasia of the basal zone cells and mucous cell metaplasia, and they do not develop inflammatory changes. The main limitation of this review is the low number and heterogeneity of studies present in the literature. In conclusion, nasal cytology is useful and allows for identifying mucosal disorders of the nasal cavities after surgery and/or radiotherapy for head and neck cancer. This can help physicians to better treat the nasal complaints of such patients.

Ocular Complications After Radiation Therapy: An Observational Study.

AIM OF THE STUDY: The study aims to quantify the incidence of ocular complications in patients irradiated on the head and neck area in our medical center, stratified by type of neoplasm and radiation dose received. MATERIALS AND METHODS: From an existing database of patients radio-treated in our center, we selected 25 patients irradiated in the 2011-2018 period. The patients had been treated for orbital lymphoma, nasopharyngeal carcinoma and cranial base meningioma. The selected patients received an ophthalmologic evaluation which included a complete ophthalmological and orthoptic assessment. RESULTS: Our results showed a significantly higher incidence of DES (dry eye syndrome) and corneal complications for eyes receiving a Dmax higher than 40 Gy, as well as for cataract incidence in eyes that had received a Dmax to the lens higher than 5 Gy. We found an overall thinning of the RNFL (retinal nerve fiber layer) in eyes that had received a Dmax higher than 50 Gy, as well as a greater MD (mean deviation) from normal visual field values. CONCLUSION: In conclusion, we can say that the study confirms the presence of a correlation between the received radiation dose and the onset of eye complications, despite the small sample.