Management of Orbital Apex Involvement in Advanced Invasive Fungal Sinusitis: Does Time of Exenteration Change Outcomes?

Introduction: Acute invasive fungal sinusitis is a rare, but rapidly progressive disease, with disease specific mortality ranging from 11 to 30% when the disease is confined within the sinonasal cavity, to 60% when it spreads to involve the orbit, and 80 to 100% when intracranial spread happens. The orbital apex is the cross roads between the latter two, and thus any involvement here must be treated aggressively, to prevent intracranial spread. However, even after early orbital exenterations, the disease may often progress. The data are sparse regarding time of onset to exenteration and associated impact on disease outcome. This study seeks to focus on this specific sub group and answer the above question.

Materials and Methods: This is a retrospective, anonymized study conducted at a national referral center. After obtaining IRB, the institutional database was searched for patients of diagnosed AIFS from 2008 onward. Patients matching the inclusion criteria were identified, and charts, operative notes and imaging was reviewed independently. Detailed statistical analysis was done and a comparative literature review was done

Inclusion Criteria: Tissue diagnosis of AIFS. Any imaging study reported “orbital apex involvement” irrespective of prior to exenteration or not. Patient underwent orbital exenteration or was offered the same, but denied consent, if satisfying no. 2. Disease-specific outcome known, or 6 months of follow-up data available.

Exclusion Criteria: Patients who already had intracranial involvement at the time of diagnosis.

Results: A total of 23 patients were included in the study. Out of these 13 patients had orbital apex involvement diagnosed on initial imaging, 10 patients presented initially with sinonasal disease, but progressed to develop new visual symptoms, 1 patient had bilateral orbital apex involvement, and 1 patient had progress of disease after orbital exenteration, and imaging demonstrated disease in the orbital apex. When adjusted for time of diagnosis to exenteration, 56.5% of the patients (13 patients) underwent exenteration within 24 hours, and survival in this group was 76.9%. On the other hand, in three patients who had delayed beyond 48 hours, mortality was 100%. In 30.4% of the study group, seven patients underwent exenteration within 24 to 48 hours, with survival being 71.4%.

On review of CT scan in staggered analysis for the sub group of progressive sinonasal disease, 87.5% were positive for sphenoid sinus involvement, and 57% were found to have possible lateral wall erosion/dehiscences.

Discussion and Conclusion: Orbital apex involvement is a serious development in patients of AIFS, and there is a significant difference in prognosis between exenteration done before 48 hours and after.

Many patients who progress on treatment have sphenoid sinus disease, and may have micro-dehiscences/erosions which may be missed on a CT sinus; hence, HRCT scan with 1-mm sections should be considered in these patients.

Due to rarity, sample size is small, and larger studies would be required to validate these results.

Fig. 1 CT scan showing sphenoid disease extending into right orbital apex.

Fig. 2 Left orbital apex syndrome with decreased vision, ptosis, and ophthalmoplegia and proptosis in a 45-year-old male patient.