Acute rhinosinusitis (ARS) is a condition characterized by inflammation of the nasal cavity and paranasal sinuses that typically lasts for up to 12 weeks according to the European Position Paper on Rhinosinusitis and Nasal Polyps (EPOS) 2020 [1]. ARS is among the top five causes of antibiotic prescriptions, accounting for one in every five reasons for antibiotic prescriptions for adults [2]. Approximately 17% to 21% of adults are diagnosed with ARS each year [3,4]. Orbital complications arising from ARS are a major concern for clinicians, often presenting with periorbital swelling, pain, and potential visual disturbances. Prompt recognition and appropriate management are crucial in preventing potential vision-threatening sequelae.

While orbital complications of rhinosinusitis are more commonly observed in children, they are also encountered in adults. However, there is limited information on the clinical features and treatment outcomes of orbital complications of rhinosinusitis in adult patients. Therefore, this retrospective observational cohort study aimed to investigate the clinical characteristics and treatment outcomes of adult patients diagnosed with orbital complications due to ARS admitted to Gyeongsang National University Hospital over the past two decades. The study included patients diagnosed with orbital complications such as cellulitis or abscess and evaluated the correlation with rhinosinusitis based on computed tomography (CT) findings.

Data from 176 patients older than 18 years of age who were admitted for orbital complications such as cellulitis or abscess at Gyeongsang National University Hospital from January 2001 to June 2022 were retrospectively collected from an electronic medical record database. Orbital complications were identified using the International Classification of Diseases, tenth revision (ICD-10) code (H050) occurring at least twice. Among 176 patients, 166 had a history of orbit or paranasal sinus CT. Non-enhanced or enhanced axial and coronal reformatted images were acquired for all cases. Two otorhinolaryngologists (YJJ and WH) who were blinded to patient clinical information and perioperative findings, evaluated the CT images and identified abnormalities in the sinuses and correlations between orbital complications and rhinosinusitis. Seventeen patients who did not show rhinosinusitis on CT were excluded. One hundred and thirty-one patients with orbital complications arising from dacryocystitis (n=114), skin infection (n=15), or other causes (n=2) were also excluded. Preseptal cellulitis, commonly categorized as a skin infection, was included in our analysis as one of the orbital complications originating from ARS, classified according to Chandler’s classification I [5]. Finally, eighteen patients were included out of the initial 176 patients (Fig. 1). The continuous data are presented as means±standard deviation and categorical data are presented as number and percentages.

In this retrospective observational cohort study, we investigated the clinical characteristics and treatment outcomes of adult patients diagnosed with orbital complications resulting from ARS. Our findings elucidate this relatively unexplored area and provide valuable insights into patient management. Notably, there have been no reported cohort studies specifically focused on adult orbital complications of ARS. Furthermore, since 2009, no original reports have been published regarding orbital complications arising from ARS in adults. This cohort study represents the longest observation period conducted at a single institution. Based on data from a previous study on the Korean adult population from January 1985 through December 2007 [6-10], the mean incidence was 1.4 patients per year, ranging from 0.2 to 2.9. Interestingly, our study yielded a similar incidence of orbital complications of ARS in adults.

ARS is a common condition that can lead to serious complications, including orbital complications, which are particularly concerning due to the potential for vision loss or life-threatening outcomes. The increased susceptibility of children to orbital complications can be attributed to several anatomical differences between pediatric and adult populations, compounded by the heightened prevalence of upper respiratory infections in children [11]. Children typically exhibit diploic-type facial bones and thinner bony separation, coupled with increased vascularity, rendering them more vulnerable to the development of orbital complications. Furthermore, previous studies on pediatric populations found male dominance in orbital complications. The demographic characteristics of the study cohort revealed a relatively equal distribution between males and females, with a mean age of 53.2 years. While orbital complications are known to occur more frequently in pediatric populations, our study demonstrates that they can also affect adults, highlighting the importance of understanding this condition in all age groups.

The majority of patients were previously healthy, emphasizing that even individuals without underlying health issues are at risk of developing serious complications following ARS. Numerous studies have explored the various risk factors associated with these complications. A prior investigation suggested that ethmoid sinusitis, male gender, dehiscence of lamina papyracea due to congenital defects or prior sinus surgery, and younger age (below 18 years) were positively correlated with ARS leading to orbital complications. Contrarily, allergic rhinitis did not exhibit any significant association with such complications [12]. Despite the abundance of studies exploring potential risk factors, a clear consensus on the definitive factors contributing to the development of ARS-related orbital complications remains elusive.

The predominant chief complaint among the patients was periorbital swelling and pain, which is consistent with previous literature on orbital complications of rhinosinusitis. In addition to periorbital swelling and pain, patients exhibited orbital symptoms such as diplopia, gaze restriction, and changes in visual acuity. These symptoms demonstrated a potential for rapid progression, underscoring the need for prompt diagnosis and intervention to avoid further deterioration and associated complications. While suspicion of an orbital complication is crucial with such symptoms, CT is considered the gold standard for diagnosis. In terms of imaging findings, CT revealed involvement of the maxillary and ethmoid sinuses in a significant proportion of patients, which is in line with the anatomical proximity of these sinuses to the orbit. Our findings corroborate previous studies, indicating a higher prevalence of orbital complications arising from maxillary and ethmoid sinusitis [12]. Frontal sinus involvement was observed in fewer patients, possibly due to the relatively less common occurrence of frontal sinusitis compared to maxillary and ethmoid sinusitis.

The identification of causative pathogens through culture results showed the presence of S. pneumoniae and P. intermedia, highlighting the importance of appropriate antibiotic selection in the management of these cases. While pathogens such as Streptococcus milleri, Streptococcus pyogenes, Streptococcus viridans, Staphylococcus aureus, Haemophilus influenza, and various anaerobes are recognized as potential contributors, the isolation of pathogens from abscesses may sometimes prove challenging [13]. In the current study, ceftriaxone emerged as the most frequently prescribed antibiotic, followed by cefotaxime and ampicillin/sulbactam. Antibiotic selection should be guided by the suspected or identified pathogens and their sensitivity profiles to ensure effective treatment.

Appropriate timing of surgical intervention was essential to optimize outcomes for patients requiring drainage procedures. Medical treatment alone was sufficient for some patients, particularly those with preseptal cellulitis, while others required surgical intervention, including endoscopic sinus surgery and external drainage for subperiosteal abscess cases. EPOS 2020 suggests that for orbital complications except for preseptal cellulitis, surgical drainage is recommended if there is no response to intravenous antibiotics within 48 hours [1]. In the present study, surgical interventions were eventually required for five patients with subperiosteal abscess.

Our study has several limitations that should be acknowledged. First, the retrospective nature of the study introduces inherent biases and limitations in data collection. Second, the relatively small sample size may limit the generalizability of our findings to larger populations. Third, the study was conducted at a single institution, potentially affecting the diversity and representation of cases. Nevertheless, this study provides valuable insights into the clinical characteristics and treatment outcomes of adult patients with orbital complications resulting from acute bacterial rhinosinusitis. The findings emphasize the significance of early recognition and prompt management of these complications to prevent severe consequences. Future prospective studies with larger, multicenter cohorts are warranted to further validate and expand on our findings and to develop evidence-based guidelines for managing these challenging cases. Improved understanding and management of adult orbital complications of ARS will contribute to better patient outcomes and reduce the burden of this condition on healthcare systems.