Background: Invasive fungal sinusitis carries high morbidity and mortality and often poses a diagnostic challenge. Orbital apex syndrome (OAS) is not an uncommon presentation in the setting of invasive fungal sinusitis. Delays in diagnosis and appropriate treatment can result in permanent visual dysfunction and, potentially, death. We present 2 cases of OAS secondary to invasive sinus aspergillosis, detailing the diagnostic process, treatment, and outcome for both patients. Subsequently, we present a review of the literature and combined analysis of our 2 patients plus 71 cases from previously published reports. Methods: Literature review was performed to identify demographic, diagnostic, clinical, and treatment data of patients with OAS caused by Aspergillus species. Results: The review resulted in 52 included articles with 71 patients, plus our 2 reported patients, leading to a total of 73 subjects included in the analysis. The average age of patients at presentation was 59.9 years. A combination of visual disturbance and pain (headache and/or periocular pain) was the most common presentation reported (46 cases; 63%). Diabetes mellitus was reported in 15 cases (21%), with more than half specifically noted to have poorly controlled diabetes. After diabetes, the second most common cause of immunocompromise was chronic steroid use (n = 13; 18%). Empiric antifungal treatment was started in 10 patients (14%), while 25 patients (34%) were first treated with systemic steroids due to a concern for an inflammatory etiology. Time to diagnosis from initial presentation was on average 7.4 weeks (range of 0.3-40 weeks). Approximately 78% of the cases (57 of 73) had biopsies with histology that confirmed Aspergillus fungal morphology, and 30/73 (41%) had diagnostic fungal cultures. The majority of the cases received monotherapy with intravenous (IV) amphotericin B (36 patients; 49%) and IV voriconazole (19 patients; 26%), with a combination of the 2 or more antifungal agents being used in 11 patients (15%). Forty patients (55%) showed signs of clinical improvement with treatment, while 33 (45%) patients did not experience any improvement or continued to deteriorate, and 23 (32%) died in the course of their reported follow-up. Conclusions: The present cases illustrate well the challenge in the diagnosis and treatment of OAS due to invasive sinus aspergillosis. Our review and analysis of 73 cases support the notion that a high index of suspicion leading to early biopsy with histology and fungal culture is paramount for diagnosis. Early empiric antifungal treatment and debridement can potentially reduce morbidity and mortality.