A Case Series of Prosthetic Rehabilitation of Post-COVID Rhinorbitocerebral Mucormycosis Ocular Defects: A Digital and Analog Experience

Abstract

Removal of a part of or the entire orbit results in facial defect, causing psychological trauma to the patient, apart from anatomic loss. This case series presents 6 clinical cases of prosthetic rehabilitation of ocular defects related to post-COVID-19 ROCM by both analog and digital workflow. The basic objective of this case series was to achieve a well retained, user-friendly, maxillofacial ocular prosthesis with esthetic accuracy. Unique size and shape of the ocular defect in each case, variety of skin tones, age range of patients and compromised neuromuscular control made each of the six cases challenging. This clinical series apart from proposing a digital & analog algorithm for rehabilitating ocular defects also illustrates analog workflow for 4 cases and digital workflow for 2 cases for fabrication of ocular prosthesis.

Introduction

Exenteration of orbital contents is associated with aesthetic and psychological impact on a patient. [1] It is done to treat potentially life-threatening ocular cancers or persistently progressing ocular disorders that fail to respond to previous treatment. Neoplasms such as basal cell carcinoma, melanoma, or squamous cell carcinoma, along with bacterial infections, trauma and fungal infections like rhino-orbit-cerebral mucormycosis (ROCM), are all etiological factors to perform orbital exenteration. [2] Severe opportunistic infections have been documented in patients with severe COVID-19 infection all over the world. During the second wave of COVID in India, secondary fungal infection like ROCM have resulted in greater mortality and morbidity rates in patients recovering from COVID-19. [3] Surgical reconstruction [4] and maxillofacial prosthetics can be used to treat orbital defects. Prosthetic rehabilitation allows fabrication of a "life-like appearance" of prosthesis with minimal surgical intervention and easy clinical surveillance of the damaged site which offers a clear advantage over surgical reconstruction. [5, 6] In literature both analog and digital methods have been used to restore ocular defect. [7] The retention in definitive prosthesis made by analog method may suffer due to the inaccessibility of significant anatomic undercuts and their arbitrary blocking out. Digital 3D imaging and rapid prototyping have been able to address the above-mentioned difficulty with additional benefits of precision, aesthetics, and treatment time reduction. [8] A collaborative effort between the surgeon and the maxillofacial prosthodontist can result in a cost-effective prosthesis that blends in with the surrounding natural tissue and also is retentive, allowing the patient to wear it with confidence. The six diagnosed patients of ROCM who underwent surgical exenteration developed ocular defects. These patients were referred to the Department of Dentistry of our Institute for prosthetic rehabilitation from the Department of Ophthalmology. During literature search on various databases we could not find an article which presents and discusses rehabilitation of ocular defects both using digital and analog protocols, in a single article. This case series also proposes digital and analog algorithm for treating ocular defects. The aim of this case series is to share our experience of processing and fabrication of a definitive ocular prosthesis using analog workflow in 4 cases and digital workflow in 2 cases.

Cases Presentation

Six diagnosed cases of ROCM are presented in Table.1, with their age, brief case history, clinical findings, surgical intervention, and prosthetic rehabilitation. Figures 1 and 2 depict ocular rehabilitation of post-exenteration ocular defects using analog and digital methods, respectively. Figure 3 illustrates the algorithm for analog and digital workflow. Written informed consent was taken from all the patients before the initiation of treatment. A follow-up was done after 1 week. Patients reported satisfaction with respect to retention and aesthetics of the prosthesis.

Table 1.

Clinical presentation of six cases

Case no	Age/sex	Brief case history	Affected site	Orbital defect shape/size	Surgical intervention	Maxillo-facial prosthetic rehabilitation
1	50yrs/M	Chief Complaint: patient presented with a complaint of pain & swelling on left side of the face and tooth bearing region of upper left jaw with an inability to open left eye since 1 month Past Medical History: Under oral medication for COVID-19 Induced diabetes mellitus type II COVID-19 History: Positive with history of oxygen therapy by mask Vaccination history: not vaccinated extraoral and intraoral clinical examination revealed: Left eye: proptosis, ptosis, oedema, conjunctival congestion, loss of vision Left maxilla and palate: Bony segmental mobility of anterior and posterior left maxilla at the level of Lefort-1 level along with unilateral necrotic mucosa and slough on hard palate. Restricted mouth opening about 2 fingers Histopathological examination: aseptate irregular branch fungal hyphae suggestive of Mucormycosis MRI Brain + PNS + Orbit: Sinusitis with left orbital cellulitis, inflammatory changes involving soft tissues of left infraorbital region, bilateral premaxillary region, spenopalatine fossa, infratemporal fossa & masticator spaces. left ICA appears to be attenuated in calibre and non-specific white matter changes	Left eye Left maxilla	Shape–oval Superior to inferior =  3.5 cm Medial to lateral = 4.0 cm	Left orbital exenteration Left infrastructure maxillectomy with left palatectomy	Left adhesive retained silicone based orbital prosthesis Heat cured acrylic obturator
2	65yrs/M	Chief complaint: patient presented with a complaint of pain & swelling on right side of the face with drooping of right eyelid along with pain while chewing and slurring of speech since 2 weeks Past Medical History: Under oral medication for diabetes mellitus type II since 2 years COVID-19 History: Positive with history of hospitalization Vaccination history: not vaccinated Extraoral and intraoral clinical examination: Right eye: proptosis, ptosis, oedema, conjunctival congestion, hazy lens, loss of vision Right Maxilla & Palate: Pale palatal mucosa with bony segmental mobility from 12 to17 region along with grade III tooth mobility of 11 and 21 Histopathological Examination: Broad aseptate hyline hyphae with wide angle branching suggestive of Mucormycosis CT Brain + Orbit + PNS: Pansinusitis with right side periorbital and orbital cellulitis of fungal etiology. Right cavernous sinus thrombo phlebitis and right ICA thrombosis	Right eye Right Maxilla	Shape -rhomboid Superior to inferior = 3.0 cm Medial to lateral = 4.0 cm	Right orbital exenteration Right infrastructure maxillectomy with right palatectomy	Right adhesive retained silicone based orbital prosthesis Heat cured acrylic obturator
3	45yrs/M	Chief complaint: patient’s attendant expressed aesthetic concern with respect to facial defect after left eye exenteration which was performed approx. 6 months ago Past medical history: under oral medication for diabetes mellitus type II since 8 years COVID-19 history: positive with history of hospitalization Vaccination history: not vaccinated Extraoral and intraoral clinical examination: Left Eye: satisfactory healing with respect to exenteration socket Right eye: loss of vision, proptosis, ptosis, oedema, swelling near medial canthus Intraorally no abnormality visualized Histopathological examination: chronic inflammation with interspersed broad, non-septate fungal hyphae suggestive of mucormycosis MRI Brain + Orbit + PNS: bilateral orbital & pre-septal cellulitis with bilateral optic neuritis and abnormal soft tissue inflammatory changes involving medial wall, extra-ocular muscles and floor of left orbit. bilateral pansinusitis, acute infarcts (?) septic in bilateral frontal,central semi ovale & left occipital lobe and bilateral intracranial ICA thrombosis	Left and right eye	Shape of left eye defect –rhomboid Superior to inferior = 2.5 cm Medial to lateral = 4.5 cm	Left orbital exenteration	Left adhesive retained silicone based orbital prosthesis
4	55yrs/F	Chief complaint: patient’s expressed aesthetic concern with respect to facial defect after right eye exenteration which was performed approx. 7 months ago Past Medical History: Under oral medication for COVID-19 Induced Diabetes Mellitus Type II COVID-19 history: positive with history of hospitalization Vaccination history: not vaccinated Extraoral clinical examination: satisfactory wound healing with respect to right eye exenteration socket Histopathological examination: broad aseptate hyline hyphae with wide angle branching suggestive of Mucormycosis CT orbit with contrast: bilateral ethmoidal, frontal, sphenoidal & left maxillary sinusitis. multiple areas of bony erosion along medial & inferior wall of right orbit with few adjacent coarse air attenuation foci reaching up to superior orbital fissure	Right eye	Shape–rhomboid Superior to inferior = 2 cm Medial to lateral  = 3.9 cm	Right orbital exenteration	Right adhesive retained silicone based orbital prosthesis
5	65yrs/F	chief complaint: presented with nasal regurgitation of food and aesthetic disfigurement due to missing left and associated facial structures Past medical history: under oral medication for hypertension since 10 years & COVID-19 Induced diabetes mellitus type II COVID-19 history: history of steroid medication while being COVID-19 positive Vaccination history: not vaccinated Extraoral clinical examination: satisfactory wound healing with respect to right eye exenteration socket Histopathological examination: panophthalmitis, foreign body granulomatous reaction & necrosis along with broad aseptate hyline hyphae with wide angle branching suggestive of Panophthalmitis with Mucormycosis MRI Brain + Orbit + PNS: right orbital cellulitis. bilateral pansinusitis. inflammatory changes involving soft tissues of bilateral pre-maxillary regions, medial canthus & infra-orbital regions, sphenopalatine fossa, infratemporal fossa & masticator spaces. chronic lacunar infarct in head of right caudate nucleus. chronic small vessel ischemic changes in Right Centrum semiovale and subcortical white matter of right frontal & right parietal lobe. mild cortico-cerebral atrophy	Right eye	Shape -rhomboid Superior to inferior = 4 cm Medial to Lateral = 3.5 cm	Right orbital exenteration	Spectacle retained silicone based orbital prosthesis
6	18yrs/M	Chief Complaint: Patient expressed aesthetic concern with respect to facial defect after left eye exenteration which was performed approx. 7 months ago past medical history: under oral medication for COVID-19 Induced diabetes mellitus type II COVID-19 History: Positive with history of hospitalization Vaccination history: not vaccinated Clinical examination: satisfactory wound healing with respect to left eye exenteration socket Histopathological examination: non-septate hyline hyphae with wide angle branching suggestive of Mucormycosis MRI PNS + brain + orbit: left orbital cellulitis. thrombosed left superior ophthalmic vein, left ICA & Left cavernous sinus possibly secondary to left sided invasive fungal pansinusitis (mucormycosis?)	Left eye	Shape–oval Superior to inferior = 2.5 cm Medial to lateral = 3.5 cm	Left orbital exenteration	Spectacle retained silicone based orbital prosthesis

Fig. 1.

Fabrication of ocular prosthesis by analog protocol

Fig. 2.

Fabrication of ocular prosthesis by digital protocol

Fig. 3.

Analog and digital workflow algorithm for fabrication of ocular prosthesis

Digital Planning and Workflow for Ocular Rehabilitation of Post-Exenteration Ocular Defects

CT (Computed Tomography) Face scan at 0.5 mm axial cuts was used to collect data about the patient’s facial anatomy by positioning their head stable and one eye open and with normal expression prior to being scanned. A 3D reconstruction model of the face of the patient was created from DICOM (Digital Imaging and Communication in Medication) Images which were imported and previewed in exocad DICOM viewer, a Dental Computer Aided Designing Software by Exocad, GmbH, Darmstadt, Germany and saved in STL format. This STL (Standard Tessellation Language) file was utilized for Rapid Prototyping by using model resin using the light-curable technology with the help of an SLA (Stereolithography) 3D printer by Free Shape SOL Model, Akcuretta, Australia. The resulting 3D Printed model is used for the fabrication of a cold-cure acrylic resin conformer. The conformer's retention and stability within the defect were re-evaluated at this point. The wax pattern was carved and finished and the iris disc was placed with care. Flasking, boiling, and packing of the wax pattern was done and post dewaxing the flask was finally packed with external silicone components along with a conformer. Deflasking was completed after 24 h. The final ocular prosthesis was finished and delivered.

Discussion

Diabetes-associated ROCM is the most prevalent manifestation of post-COVID-19 [3]. COVID-19 was declared a global pandemic by WHO. Because of poor understanding of the disease, its pathogenesis, and effective treatments, hypoxemic patients were treated with a variety of drugs (steroids, antibiotics, ivermectin, remdesivir, and tocilizumab), plasma therapy, oxygen therapy, and ventilation. Patients with DM are predisposed to COVID-19. A large meta-analysis of 851 ROCM cases found that DM was a risk factor [9]. The clinical signs of ROCM include central retinal artery occlusion and panophthalmitis. Other symptoms include proptosis and ptosis, facial swelling/discoloration, restricted ocular motility, visual loss, fixed pupils, and nasal or palatal eschar. Table 1 illustrates clinical signs of ROCM in our patients. Liposomal Amphotericin-B (5–10 mg/kg/day) or intravenous posaconazole or isavuconazole are used as medical line of treatment. [10] As a matter of course, a fungal disease such as this is staged as follows: stage 1 involves the nasal mucosa; stage 2 involves the paranasal sinuses; stage 3 involves the orbits (3a: nasolacrimal duct and medial orbit; 3b: diffuse orbit) stage 4 involves the central nervous system. The removal of the paranasal sinuses by turbinectomy, palatal resection, or medial orbital wall resection is required in stages 1, 2, and 3 of the disease. Stage 3c disease, with thrombosis of the central retinal artery or superior ophthalmic vein, and Stage 4 disease, with central nervous system involvement, will necessitate orbital exenteration/neurosurgical therapy. [11] After orbital exenteration, prosthetic rehabilitation was started in cases mentioned in Figs. 1 and 2. The definitive prosthesis in all cases was made from room temperature vulcanizing silicone. The cases as depicted in Fig. 1 were processed and completed by Analog method. Gunjan Pruthi et al. published a case series on prosthetic rehabilitation after orbital exenteration. In this case series the authors used different types of retentive aids for ocular prostheses like pin and socket, magnetic buttons, spectacles frame but in our case series, we have utilized anatomical undercuts and silicone based adhesives (Pro Bond) for retention [5]. In this case series the definitive prosthesis made by analog method had large defect sizes and all cases done by analog protocol had neurological involvement resulting in compromised manual dexterity so we could not use magnetic and pin socket attachment in these cases. 2 Cases as illustrated in Fig. 2 were processed by the digital protocol and completed by using analog method. In the digital protocol, we used 3D model of the patient’s face which was printed digitally using dental cad software (Exocad, Germany). The 3D printed model was used for fabrication of an acrylic conformer. Our digital protocol was different from an earlier published case report by Radhika A et al. in which they have described fabrication of an orbital prosthesis composed of a digitally produced acrylic resin conformer and traditionally produced silicon prosthesis [7]. Another case report published by Yunprn bi et al. describes digitally produced negative mold and packing of silicone done conventionally [8].

In this clinical case series Case number 5 had a large defect size and compromised bone support whereas case number 6 had a shallow defect, therefore to provide retention a spectacle-retained prosthesis was fabricated.

Usage of dental implants over adhesives and other mechanical retentive aids have been described in literature with advantages like better retention in large defects and convenient positioning of definitive prosthesis. [11–14] The advantages mentioned offer a greater acceptance by patient especially in younger individuals. In our case series, all the patients had a history of ROCM and Diabetes Mellitus II, in which the bone quality in the orbital region was compromised, and the overall general health of the patients also restricted the usage of implant retained ocular prosthesis in such patients. Shade matching of silicone with the patient’s skin, using intrinsic stains was challenging in all cases. Shade of the prosthesis turned out to be slightly darker in case 2 than the surrounding skin, whereas in rest of the cases shade matching was found to be satisfactory .

Conclusion

The rehabilitation of orbital defects due to ROCM is challenging, but both analog and digital methods improve aesthetics and contribute to the patient's mental and social well-being. The digital method accurately reconstructs the orbital defect and is far less time-consuming. However, as a limitation, the digital method is costly in the Indian scenario.

Authors Contribution

Each author contributed equally in conceptualizing, collection of data, editing and proof reading of the article.

Funding

The authors did not receive support and/or any funding from any organization for the submitted work.

Data availability

Data and material used in this study are readily available with the corresponding author and may be reproduced on request.

Declarations

Conflict of interest

None.

Ethics Approval

Not required as per Institutional Guidelines. However, Case Report (CARE) guidelines were followed.

Informed Consents

Written informed consent was obtained from the patients for publication of this case series. Consent may be produced to the editorial office upon reasonable request.