Ocular invasion in mucormycosis

Outcome of Total Surgical Debridement of Covid Associated Rhino-Orbito-Cerebral Mucormycosis Based on a New Surgical Staging System: A Cohort Study

To propose a surgical staging system with management protocol for post-covid Rhino-orbito-cerebral mucormycosis (ROCM) with central skull base osteomyelitis. A prospective cohort study of a total of 193 post-covid ROCM patients was conducted between May 2021 and January 2022 at a tertiary care centre. Patients were assessed radiologically and staged from I to V. Follow up period was 16 months and the surgical outcome in terms of recurrent disease was assessed. A total of 193 patients (129 primary and 64 revision) were studied. Maxilla was found to be the epicenter of anterior disease (69.3%) and pterygoid wedge was noted to be the epicenter of posterior disease (85.6%). More than 65% of our patients, at the time of presentation, presented with involvement of the central skull base. Intracranial disease was noted in 13.9% of patients and the mortality rate was 6.2%. This staging system provides a systematic step-by-step protocol for the management of ROCM, with emphasis on meticulous disease clearance at the central skull base.

Spectral Domain Optical Coherence Tomography Findings in Vision-Threatening Rhino-Orbital Cerebral Mucor Mycosis-A Prospective Analysis

Rhino-orbital cerebral mucor mycosis is a rare disease entity, where retinal involvement is described in the literature mostly as CRAO. However, pathological studies have shown mucor invading the choroid and retina with a neutrophilic reaction. So, it is pertinent that retinal inflammation secondary to invading mucor has some role in microstructural changes seen in the vitreous and retina of these patients. This novel study aims to describe the vitreal and retinal features of patients with vision-threatening rhino-orbital cerebral mucor mycosis and how they evolve on spectral domain optical coherence tomography (SD-OCT). This study shall also provide insight into the pathophysiology of these vitreoretinal manifestations by in vitro analysis of the exenterated orbital content. Fifteen eyes of fifteen patients with vision-threatening ROCM treated with standard care were enrolled in this study and underwent complete ophthalmic examination, serial colour fundus photography, and SD-OCT for both qualitative and quantitative analysis, at baseline and follow-up visits. SD-OCT on serial follow-up revealed thickening and increased inner-retinal reflectivity at presentation followed by thinning of both, other features such as the loss of the inner-retinal organized layer structure, external limiting membrane (ELM) disruption, necrotic spaces in the outer retina, and hyperreflective foci. Vitreous cells with vitreous haze were also seen. There was a significant reduction in CMT, inner and outer retinal thickness, total retinal thickness (all p < 0.05) with time, the quantum of reduction concentrated primarily to the inner retina. In summary, in vivo and in vitro analysis revealed that early microstructural changes were primarily a result of retinal infarctions secondary to thrombotic angioinvasion. With the late microstructural changes, there was possible sequelae of retinal infarction with some contribution from the inflammation, resulting from mucor invading the choroid and retina.

Treatment of Rhinocerebral Mucormycosis by Combination of Endoscopic Sinus Debridement and Amphotericin B

Rhinocerebral mucormycosis (RCM) is an aggressive fungal infection with a high mortality rate. It frequently develops in patients with uncontrolled diabetes mellitus or immunocompromised patients. RCM typically presents in a rapidly fulminant manner with headache, fever, mucosal necrosis, and ophthalmic symptoms. Although the definitive diagnosis is achieved by histopathological examination, computed tomography (CT) scanning and magnetic resonance (MR) are the best imaging procedures in early diagnosis to assess the extent of the disease.

Acute orbital apex syndrome and rhino-orbito-cerebral mucormycosis

Purpose

To demonstrate the successful clinical identification and management of rhino-orbital mucormycosis, a fungal infection with a high mortality rate.

Patients and methods

A diabetic male patient with a headache and orbital apex syndrome in the right eye was examined using computed tomography (CT) and magnetic resonance imaging (MRI) for a possible fungal infection. Endoscopic surgical resection was performed and a pathology sample was taken. Specimens were prepared with Gömöri methenamine silver and hematoxylin and eosin staining. The patient was treated with liposomal amphotericin B 400 mg daily, followed by posaconazole 400 mg twice daily.

Results

CT and MRI revealed a mass of the right sphenoid spreading into the orbit, indicative of a fungal infection. The biopsy confirmed the diagnosis of mucormycosis. Complete recovery of eyelid and oculomotor function was achieved after 10 months of treatment, although the patient continues to suffer from irreversible blindness in the right eye due to optic nerve atrophy. He has been without signs or symptoms of recurrence.

Conclusion

Patients with rhino-orbito-cerebral mucormycosis need extensive surgical and medical treatment to maximize outcomes. Success requires multidisciplinary management.

Epidemiology and outcome of zygomycosis: a review of 929 reported cases

BACKGROUND

Zygomycosis is an increasingly emerging life-threatening infection. There is no single comprehensive literature review that describes the epidemiology and outcome of this disease.

METHODS

We reviewed reports of zygomycosis in the English-language literature since 1885 and analyzed 929 eligible cases. We included in the database only those cases for which the underlying condition, the pattern of infection, the surgical and antifungal treatments, and survival were described.

RESULTS

The mean age of patients was 38.8 years; 65% were male. The prevalence and overall mortality were 36% and 44%, respectively, for diabetes; 19% and 35%, respectively, for no underlying condition; and 17% and 66%, respectively, for malignancy. The most common types of infection were sinus (39%), pulmonary (24%), and cutaneous (19%). Dissemination developed in 23% of cases. Mortality varied with the site of infection: 96% of patients with disseminated disease died, 85% with gastrointestinal infection died, and 76% with pulmonary infection died. The majority of patients with malignancy (92 [60%] of 154) had pulmonary disease, whereas the majority of patients with diabetes (222 [66%] of 337) had sinus disease. Rhinocerebral disease was seen more frequently in patients with diabetes (145 [33%] of 337), compared with patients with malignancy (6 [4%] of 154). Hematogenous dissemination to skin was rare; however, 78 (44%) of 176 cutaneous infections were complicated by deep extension or dissemination. Survival was 3% (8 of 241 patients) for cases that were not treated, 61% (324 of 532) for cases treated with amphotericin B deoxycholate, 57% (51 of 90) for cases treated with surgery alone, and 70% (328 of 470) for cases treated with antifungal therapy and surgery. By multivariate analysis, infection due to Cunninghamella species and disseminated disease were independently associated with increased rates of death (odds ratios, 2.78 and 11.2, respectively).

CONCLUSIONS

Outcome from zygomycosis varies as a function of the underlying condition, site of infection, and use of antifungal therapy.

Novel perspectives on mucormycosis: pathophysiology, presentation, and management

Mucormycosis is a life-threatening fungal infection that occurs in immunocompromised patients. These infections are becoming increasingly common, yet survival remains very poor. A greater understanding of the pathogenesis of the disease may lead to future therapies. For example, it is now clear that iron metabolism plays a central role in regulating mucormycosis infections and that deferoxamine predisposes patients to mucormycosis by inappropriately supplying the fungus with iron. These findings raise the possibility that iron chelator therapy may be useful to treat the infection as long as the chelator does not inappropriately supply the fungus with iron. Recent data support the concept that high-dose liposomal amphotericin is the preferred monotherapy for mucormycosis. However, several novel therapeutic strategies are available. These options include combination therapy using lipid-based amphotericin with an echinocandin or with an azole (largely itraconazole or posaconazole) or with all three. The underlying principles of therapy for this disease remain rapid diagnosis, reversal of underlying predisposition, and urgent surgical debridement.

Rhinocerebral mucormycosis: pathways of spread

Rhinocerebral mucormycosis is an invasive, opportunistic fungal infection usually seen in immunocompromised patients, and particularly in the setting of diabetes or immune deficiency. It is assumed that the port of entry is colonization of the nasal mucosa, allowing the fungus to spread via the paranasal sinuses into the orbit. Involvement of the brain and cavernous sinus occurs by way of the orbital apex; therefore, spheno-ethmoidectomy with or without maxillectomy seems to be the definitive method to eradicate this infection. We conducted a prospective study of ten patients with rhinocerebral mucormycosis from February 2000 to April 2004. Rhinocerebral mucormycosis was clinically diagnosed in 11 patients, 10 of whom were included in our study upon histopathological confirmation. Diabetes was the most common underlying disorder seen in nine out of ten patients. In this study, the patients were assessed for predisposing factors, presenting signs and symptoms, sites of extension, the number and sites of surgical debridement, as well as the outcome. Ocular, sinonasal and facial soft tissue involvement was common. Involvement of the pterygopalatine fossa at the time of debridement was evident in all patients. No invasion through the lamina papiracea or the walls of the maxillary sinus was identified. At the time of this communication, six out of ten patients were alive. For the four who died, the causes were hypokalemia, cardiac arrythmia and refractory pneumonia. Pterygopalatine fossa is considered to be the main reservoir for rhinocerebral mucormycosis, and extension into the orbit and facial soft tissues usually follows this route. After proliferation in the nasal cavity, the mucor reaches the pterygo-palatine fossa, inferior orbital fissure and finally the retroglobal space of the orbit, resulting in ocular signs. The facial soft tissues, palate and infratemporal fossa can be infected through connecting pathways from the pterygo-palatine fossa; therefore, debridement of the pterygopalatine fossa seems to be the definitive method of managing this infection.

Fatal strokes in patients with rhino-orbito-cerebral mucormycosis and associated vasculopathy

Within a 10-y period, fatal strokes occurred during parenteral administration of amphotericin B and surgical debridement of paranasal sinuses in 6 pathologically verified cases of rhino-orbito-cerebral mucormycosis (ROCM). All patients had unnoticed type-2 diabetes mellitus without ketoacidosis. They presented with unilateral orbital cellulitis and cavernous sinus syndrome. Fatal malignant cerebral infarctions occurred in the carotid system in 5 patients, and in the basilar artery or its major branches in 2 patients. Accelerated thrombotic occlusion of the cavernous portion of the carotid artery or the basilar artery was likely to be due to mucormycosis associated-vasculopathy and diabetic vasculopathy. One patient died of massive subarachnoid hemorrhage following rupture of the mycotic aneurysm. Despite parenteral administration of amphotericin B, fatal outcome of ROCM in patients with unnoticed diabetes mellitus occurs due to mucormycosis-associated malignant strokes. To improve outcome, a combination of early radical debridement, ocular exenteration, parenteral and local administration of amphotericin B, and decompression craniotomy should be considered.

Improved outcome of zygomycosis in patients with hematological diseases?

Zygomycosis is an opportunistic fungal infection that is increasingly reported in hematological patients. We describe 2 cases of successfully treated rhino-cerebral zygomycosis and give an overview of 120 patients from the literature with underlying hematological or oncological disorders. These data document the improved survival in sinus (15/17 patients surviving) and cutaneous (6/9 patients surviving) disease. Hematological patients with pulmonary (9/30 patients surviving) or disseminated (4/38 patients surviving) zygomycosis still have a poor prognosis. The clinical course of sinus-orbital involvement (4/11 patients surviving) follows sinus-cerebral (2/3 patients surviving) or cerebral (3/6 patients surviving) disease. Besides deoxycholate amphotericin B (AmB) (24/62 patients surviving), patients seem to benefit from liposomal amphotericin B (L-AmB) (10/16 patients surviving) or sequential AmB/L-AmB treatment (6/8 patients surviving). Alternative treatment options lead only in a few patients to success.

Current perspectives on ophthalmic mycoses

Fungi may infect the cornea, orbit and other ocular structures. Species of Fusarium, Aspergillus, Candida, dematiaceous fungi, and Scedosporium predominate. Diagnosis is aided by recognition of typical clinical features and by direct microscopic detection of fungi in scrapes, biopsy specimens, and other samples. Culture confirms the diagnosis. Histopathological, immunohistochemical, or DNA-based tests may also be needed. Pathogenesis involves agent (invasiveness, toxigenicity) and host factors. Specific antifungal therapy is instituted as soon as the diagnosis is made. Amphotericin B by various routes is the mainstay of treatment for life-threatening and severe ophthalmic mycoses. Topical natamycin is usually the first choice for filamentous fungal keratitis, and topical amphotericin B is the first choice for yeast keratitis. Increasingly, the triazoles itraconazole and fluconazole are being evaluated as therapeutic options in ophthalmic mycoses. Medical therapy alone does not usually suffice for invasive fungal orbital infections, scleritis, and keratitis due to Fusarium spp., Lasiodiplodia theobromae, and Pythium insidiosum. Surgical debridement is essential in orbital infections, while various surgical procedures may be required for other infections not responding to medical therapy. Corticosteroids are contraindicated in most ophthalmic mycoses; therefore, other methods are being sought to control inflammatory tissue damage. Fungal infections following ophthalmic surgical procedures, in patients with AIDS, and due to use of various ocular biomaterials are unique subsets of ophthalmic mycoses. Future research needs to focus on the development of rapid, species-specific diagnostic aids, broad-spectrum fungicidal compounds that are active by various routes, and therapeutic modalities which curtail the harmful effects of fungus- and host tissue-derived factors.

Rhino-orbital and rhino-orbito-cerebral mucormycosis

BACKGROUND

Rhino-orbito-cerebral mucormycosis (ROCM) is a devastating infection of immunocompromised hosts. We present our experience with 19 ROCM cases and attempt to define preferred diagnostic and treatment protocols.

METHODS

All had tissue biopsies obtained studied by direct smear, histologic studies, and cultures. Imaging was obtained in 14 cases.

RESULTS

Sixteen patients presented between August and November. Six had mixed fungal infections. Seven patients had end-stage underlying disease or infection and did not undergo surgery and 4 had an indolent form of disease. Patients were treated by surgery and by amphotericin B. The overall survival was 47%.

CONCLUSIONS

ROCM may have seasonal incidence peaking in the fall and early winter. The therapeutic approach should be unchanged in cases of mixed fungal infections. Amphotericin B with aggressive debridement remains the mainstay of treatment. Early recognition and treatment are essential. A presentation and survival-dependent classification of ROCM are offered.

Fungal and parasitic infections of the eye

The unique structure of the human eye as well as exposure of the eye directly to the environment renders it vulnerable to a number of uncommon infectious diseases caused by fungi and parasites. Host defenses directed against these microorganisms, once anatomical barriers are breached, are often insufficient to prevent loss of vision. Therefore, the timely identification and treatment of the involved microorganisms are paramount. The anatomy of the eye and its surrounding structures is presented with an emphasis upon the association of the anatomy with specific infection of fungi and parasites. For example, filamentous fungal infections of the eye are usually due to penetrating trauma by objects contaminated by vegetable matter of the cornea or globe or, by extension, of infection from adjacent paranasal sinuses. Fungal endophthalmitis and chorioretinitis, on the other hand, are usually the result of antecedent fungemia seeding the ocular tissue. Candida spp. are the most common cause of endogenous endophthalmitis, although initial infection with the dimorphic fungi may lead to infection and scarring of the chorioretina. Contact lens wear is associated with keratitis caused by yeasts, filamentous fungi, and Acanthamoebae spp. Most parasitic infections of the eye, however, arise following bloodborne carriage of the microorganism to the eye or adjacent structures.

Fungal and parasitic infections of the eye

The unique structure of the human eye as well as exposure of the eye directly to the environment renders it vulnerable to a number of uncommon infectious diseases caused by fungi and parasites. Host defenses directed against these microorganisms, once anatomical barriers are breached, are often insufficient to prevent loss of vision. Therefore, the timely identification and treatment of the involved microorganisms are paramount. The anatomy of the eye and its surrounding structures is presented with an emphasis upon the association of the anatomy with specific infection of fungi and parasites. For example, filamentous fungal infections of the eye are usually due to penetrating trauma by objects contaminated by vegetable matter of the cornea or globe or, by extension, of infection from adjacent paranasal sinuses. Fungal endophthalmitis and chorioretinitis, on the other hand, are usually the result of antecedent fungemia seeding the ocular tissue. Candida spp. are the most common cause of endogenous endophthalmitis, although initial infection with the dimorphic fungi may lead to infection and scarring of the chorioretina. Contact lens wear is associated with keratitis caused by yeasts, filamentous fungi, and Acanthamoebae spp. Most parasitic infections of the eye, however, arise following bloodborne carriage of the microorganism to the eye or adjacent structures.

Long-term survival in rhinocerebral mucormycosis. Case report

Mucormycosis refers to a group of rapidly progressive infections caused by fungi belonging to the order Mucorales. Infection most often develops in individuals with immunological or metabolic compromise, although patients without underlying abnormalities have been affected. Specific clinical manifestations are associated with various predisposing factors. Rhinocerebral mucormycosis is the most common form and most frequently develops in individuals with poorly controlled diabetes mellitus. The extent of anatomical involvement and clinical course are unpredictable, depending on the intrinsic factors of the host. Over the past 20 years the prognosis for patients with rhinocerebral mucormycosis, once considered to be a uniformly fatal disease, has improved. Coordinated medical and surgical treatment, including rapid diagnosis, the advent of systemic antifungal agents, aggressive surgical debridement, and control of the underlying disease process, have been credited with its successful management. The range of survival rates recorded with the regimen of combined therapies is wide because the number of patients reported is limited and anatomical involvement is diverse. Survival with intracerebral abscess is rare. The authors describe the successful management of a patient who developed a bifrontal fungal abscess during treatment for rhinocerebral mucormycosis associated with ketoacidosis and diabetes mellitus. The patient remains without radiographic or clinical evidence of infection more than 2 years after treatment. The authors review the characteristic clinical, radiographic, and pathological features of previously reported infections and emphasize the importance of early detection and aggressive treatment in the management of this frequently fulminant and fatal disease.

Survival factors in rhino-orbital-cerebral mucormycosis

Mucormycosis is a highly aggressive fungal infection affecting diabetic, immunocompromised, and, occasionally, healthy patients. This infection is associated with significant mortality. We have reviewed 208 cases in the literature since 1970, 139 of which were presented in sufficient detail to assess prognostic factors, and added data from six of our patients. The histories of these 145 patients were analyzed for the following variables: 1) underlying conditions associated with mucormycotic infections; 2) incidence of ocular and orbital signs and symptoms; 3) incidence of nonocular signs and symptoms; 4) interval from symptom onset to treatment; and 5) the pattern of sinus involvement seen on imaging studies and noted at the time of surgery. Factors related to a lower survival rate include: 1) delayed diagnosis and treatment; 2) hemiparesis or hemiplegia; 3) bilateral sinus involvement; 4) leukemia; 5) renal disease; and 6) treatment with deferoxamine. The association of facial necrosis with a poor prognosis fell just short of statistical significance, but appears clinically important. This is the first review that documents the heretofore intuitive claim that early diagnosis is necessary to cure this disease. Standard treatment with amphotericin B and aggressive surgery are reviewed and adjunctive therapeutic modalities are discussed, including local amphotericin B irrigation, hyperbaric oxygen, and optimizing the immunosuppressive regimen in transplant patients. Hyperbaric oxygen was found to have a favorable effect on prognosis. In addition, possible treatment options for patients with declining renal function are reviewed.

Orbital infarction syndrome

BACKGROUND

The authors define orbital infarction as ischemia of all intraorbital and intraocular structures. It is a rare disorder due to the rich anastomotic vascularization of the orbit.

PATIENTS

The authors report three patients with orbital infarction with similar clinical presentations: acute blindness, orbital pain, total ophthalmoplegia, and anterior and posterior segment ischemia.

RESULTS

Etiologies of orbital infraction syndrome include occlusion of the common carotid artery (case 1), giant-cell arteritis (case 2), and mucormycosis (case 3).

CONCLUSION

Three cases discussed in this article illustrate that orbital infarction is a disorder that can occur secondary to different mechanisms such as (1) acute perfusion failure (e.g., common carotid artery occlusion [possibly combined with anomalous orbital anastomotic channels]), 2) systemic vasculitis (e.g., giant-cell arteritis), and (3) orbital cellulitis with vasculitis (mucormycosis). The blindness and retinal and optic nerve damage were permanent, whereas the other signs of orbital ischemia (ophthalmoplegia and anterior segment ischemia) resolved. Therefore, diagnosis of orbital infarction can best be made during the acute phase.