Introduction
The tale goes in ancient Greek mythology that the phoenix (a long-lived bird) is born again by rising from the ashes of its predecessor.
Such is the tale of this pathogen, which in recent times has risen like the phoenix from the ashes. 1
Like most monsters, a Phoenix could be killed, by being shot with the ‘Colt’.
Rhino-orbital mucormycosis is a infection of the orbital tissues by the fungus Mucor of the class Phycomycetes (order Mucorales). 2
Mucormycosis is a severe and often fatal acute fungal disease. The angio-invasive behavior of the fungus leads to thrombosis, tissue necrosis, and invasion of adjacent tissues, thereby minimizing the local availability of systemic antifungals and making aggressive surgical approaches necessary. 3, 4
When affecting the sinus, rhinoorbito-cerebral mucormycosis (ROCM) can extend to the orbital tissues, increasing the risk of central nervous system (CNS) involvement and death. In such cases, exenteration is commonly indicated. 4, 5, 6
With unclear guidelines regarding the optimal timing for exenteration, given this procedure’s disfiguring outcome, alternative methods of treatment should be considered.
Unique and potentially globe sparing approach is retrobulbar antifungal injection
Materials and Methods
Retrospective, institutional study, carried out in the department of ophthalmology from March 2021 to June 2021.
23 patients of biopsy proven mucormycosis and radiographic evidence of orbital involvement were enrolled in this study.
Were in group A and 10 in group B
Group A consists of patients who were treated with retrobulbar liposomal amphotericin B and group B consists of patients who were treated with intravenous liposomal amphotericin B.
The patients of group A were treated with retrobulbar liposomal amphotericin B (1ml of 3 mg/kg/day LAMB with an antecedent retrobulbar injection of anesthetic comprised of 2 ml of 2% lidocaine) and the patients were given five retrobulbar injections during their course in the hospital.
And group B patients were treated with intravenous liposomal amphotericin B (5mg /kg/day liposomal Amphotericin B in 500 mL D5 with 10 Units Human insulin regular), intravenous micafungin 6mg/kg/day every 24 hours, and oral posaconazole 300 mg every 24 hour for a week.
Results
In this study which included 23 patients of rhino orbital mucormycosis, in which group A patients who were treated with retrobulbar amphotericin B and group B patients who were treated with intravenous amphotericin B.
Out of 13 patients in group A, only one patient underwent exenteration and the patient survived post exenteration. Among the other 12 patients, 10 patients survived.
In group B, out of ten, four patients were subjected to exenteration, out of which two survived. Among the other six patients without exenteration, five of them survived.
Discussion
Mucormycosis is a potentially life-threatening condition which requires prompt recognition and treatment.
Challenges in treating ROCM due to its underlying pathogenesis in which endothelial cell damage leads to vascular thrombosis decreasing the efficacy of systemic antifungals5.
In progressive orbital disease, exenteration may be recommended; however, there are no clear guidelines regarding optimal timing for exenteration. 6, 7
Although potentially life-saving, exenteration carries significant complications including certain blindness, cosmetic disfigurement and psychosocial trauma. 8
Management of mucormycosis consists of immediate initiation of systemic anti-fungals.
In the recent years, with the purpose of reducing mortality and the need for potentially disfiguring procedures such as exenteration, several alternative, and/or adjuvant treatments have been proposed, including modern antifungal medications (e.g., posaconazole), local antifungals, hyperbaric therapy, and cautious debridement.
In 1969, Fleckner and Goldstein 9 reported 2 cases of rhino-orbital mucormycosis treated with both systemic and local irrigation of amphotericin B. Since then, descriptions of local antifungal irrigation both intra- and postoperatively have sporadically appeared in the medical literature. 10, 11, 12
In the literature of invasive fungal infections caused by the Mucoraceae family of fungi treated with orbital irrigation of amphotericin B.
Treatment regimens reported in the literature consist of daily to 4 times daily irrigations of amphotericin B, with concentrations ranging from 0.25 to 1.25mg/ml, and volumes of 1 to 15ml. Durations of treatment range from 5 days to 4 weeks. Only 1/10 required orbital exenteration, and most retained excellent visual acuity; none of the patients died from the primary infection. 13
Luna et al presented a case of rhino-orbital mucormycosis successfully treated with orbital irrigation of amphotericin B through an Abbocath No. 18 catheter (Hospira, Inc., Lake Forest, IL, U.S.A.) directly in the muscle cone. 13
Saiff et al. reported a case of ROCM associated with left temporal cerebritis on nuclear MRI that was successfully treated with retrobulbar applications of amphotericin B, which resulted in avoidance of exenteration. 14
And few other studies have been reported successful treatment after retrobulbar amphotericin B (TABLE)
Liposomal amphotericin B is often the antifungal agent of choice due to superior survival rates and the ability to achieve higher blood levels without the immediate nephrotoxic side effects commonly seen with the deoxycholate formulation. 15
Intraorbital irrigation of amphotericin B, which is not yet routinely used in the management of this devastating and frequently fatal disease, is a modality that was found to be useful.
The use of this technique is recommended in all cases of rhino-orbital mucormycosis infections, except for cases in which exenteration is clearly indicated or when palliative therapy has been decided upon.
In this study,
Group A out of 13 patients, only one patient underwent exenteration and the patient survived post exenteration. Among the other 12 patients, 10 patients survived.
In group B, out of ten, four patients were subjected to exenteration, out of which two survived. Among the other six patients without exenteration, five of them survived.
Thus this study suggests that, with retrobulbar amophotericin B the incidence of disfiguring exenteration was lower compared to intrvenous amphotericin B.
Needs furthermore studies to conclude this.
Conclusion
Rhino orbital mucormycosis is best managed by immediate initiation of intravenous anti-fungals, reversing the patient’s immunocompromised state. In the setting of progressive orbital disease, retrobulbar amphotericin B treatment should be considered as an option prior to exenteration.
In this study patients who were treated with retrobulbar amophotericin B had a lower risk of disfiguring exenteration without an apparent increase in the risk of mortality.
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