|EXPEDITED PUBLICATION, COMMENTARY
|Year : 2021 | Volume
| Issue : 2 | Page : 131-132
Transcutaneous retrobulbar amphotericin B and exenteration in rhino-orbital cerebral mucor mycosis: Do we know it all yet?
Ophthalmic Plastic Surgery Service, LV Prasad Eye Institute, Hyderabad, Telangana, India
|Date of Submission||13-Jun-2021|
|Date of Acceptance||13-Jun-2021|
|Date of Web Publication||24-Jun-2021|
Dr. Milind Naik
Ophthalmic Plastic Surgery Service, LV Prasad Eye Institute, Hyderabad
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Naik M. Transcutaneous retrobulbar amphotericin B and exenteration in rhino-orbital cerebral mucor mycosis: Do we know it all yet?. TNOA J Ophthalmic Sci Res 2021;59:131-2
|How to cite this URL:|
Naik M. Transcutaneous retrobulbar amphotericin B and exenteration in rhino-orbital cerebral mucor mycosis: Do we know it all yet?. TNOA J Ophthalmic Sci Res [serial online] 2021 [cited 2021 Jul 27];59:131-2. Available from: https://www.tnoajosr.com/text.asp?2021/59/2/131/319269
Rhino-orbital cerebral mucormycosis (ROCM) has been a relatively rare disease, affecting the severely immunocompromised and cancer patients. Only recently, has it reached epidemic proportions in India during the second wave of COVID-19 pandemic. Apart from our ENT colleagues who perform the primary sinus debridement, the ophthalmic plastic surgery colleagues are most active with two contributions to the management of ROCM: Transcutaneous retrobulbar amphotericin B (TRAMB) and orbital exenteration. However, there is a big gap between available knowledge, and the frequency with which these two options are recommended. Here, I would like to make the ophthalmic community aware of these lacunae and may be impart a feeling of caution while exercising any of these.
| Transcutaneous Retrobulbar Amphotericin B|| |
There is truly little literature available about TRAMB., At present, there are more unanswered questions about TRAMB than useful data, and we would have to wait until enough literature accumulates to give the verdict on its utility in the management of ROCM. First, let us enumerate possible indications where TRAMB is likely to be considered suitable:
- Preserved vision, with focal involvement of the orbit
- Unavailability of Amphotericin for intravenous use (IV) in patients with orbital involvement
- Following sinus debridement where orbital wall has been breached.
What is it that we do not know about TRAMB yet? First, the number of injections to be given is unclear. Second, the optimal dose has not yet been arrived at, and the only option we have is to replicate the dosage described in prior publications. Third, it's possible side effects such as neurotoxicity, compartment syndrome, raised IOP are not well studied, and we do not know how frequently to expect them.
Therefore, my take on TRAMB is to best avoid it when contrast scan reveals good vascular permeation within the orbit, and the patient is on systemic anti-fungals. Moreover, patients with disfigured, painful blind eyes with a frozen globe are best exenterated than subjected to repeated TRAMB. Only well-designed prospective randomized studies can throw more light on its utility. At present, majority of clinicians who have exercised this option have found it to be of limited use.
| Exenteration|| |
Even in the pre-COVID era, exact indications of exenteration (and their effect on survival outcomes) were not well-understood in the management of ROCM.
The goal is to salvage the vision and the globe as far as possible. However, due to the rapid spread, angio-invasive nature of mucor, and high mortality rate if intracranial, it is natural for a clinician to think that an early exenteration could be life-saving.
Ideal indications for exenteration in ROCM that many would agree upon include:
- Disfigured blind eye with no light perception, diagnosed central retinal artery occlusion (CRAO), and not-responding to IV antifungal therapy
- Diffuse involvement of the orbit including apex, with no visual potential
- Orbital disease progression despite antifungal therapy and sinus debridement.
In my personal opinion, exenteration can be avoided in the following cases:
- Partial or intact vision, but only ophthalmoplegia
- Documented response to sinus debridement or IV antifungal therapy
- Extensive central nervous system (CNS) spread, where exenteration is unlikely to change the survival outcome
- Critically ill patients who would not tolerate the anesthesia or surgical intervention due to comorbidities.
If the CNS involvement is focal, it can be surgically debrided. However, if the CNS involvement is diffuse, the orbital disease is best treated medically, and exenteration be kept as the last resort, in consultation with the neurology team (chances of life salvage) and patient's willingness to undergo an exenteration. For bilateral orbital involvement and CNS spread, choosing a bilateral exenteration is indeed one of the toughest choices an ophthalmologist would have to make. In this case, it should be the last resort, when the neurologist is fairly confident that the CNS disease can be medically controlled, and where the patient's desire to live is stronger than the desire to retain a blind eye at the risk of losing life.
| References|| |
Hirabayashi KE, Kalin-Hajdu E, Brodie FL, Kersten RC, Russell MS, Vagefi MR. Retrobulbar injection of amphotericin B for orbital mucormycosis. Ophthalmic Plast Reconstr Surg 2017;33:e94-7.
Safi M, Ang MJ, Patel P, Silkiss RZ. Rhino-orbital-cerebral mucormycosis (ROCM) and associated cerebritis treated with adjuvant retrobulbar amphotericin B. Am J Ophthalmol Case Rep 2020;19:100771.
Hargrove RN, Wesley RE, Klippenstein KA, Fleming JC, Haik BG. Indications for orbital exenteration in mucormycosis. Ophthalmic Plast Reconstr Surg 2006;22:286-91.