Kelvin Kam-lung Chong
Dr. Kelvin Chong is a surgeonscientist in orbital and oculoplastic surgery and related cell biology. He graduated at the top of his class in the Bachelor of Medicine and Surgery (CUHK) program. He was awarded the Li Po Chun Charitable Trust Fund Overseas Postgraduate Scholarship where he continued later as an international clinical and research fellow at the University of California at Los Angeles (UCLA) (preceptor: Prof. Robert Goldberg) and LA Biomedical Institute (Preceptor: Prof. Terry Smith and Dr Raymond Douglas). His awards included the City Lion Club Gold Medal, Action for Vision Eye Foundation Young Researcher of the Year, Exemplary Eye Resident Award, Achievement Awards from American Academy of Ophthalmology and Asia Pacific Academy of Ophthalmology. Dr. Chong serves as the Coordinator of Orbital and Oculoplastic Surgery at the teaching hospital of the CUHK, the Prince of Wales Hospital and the CUHK Eye Center. He is the current vice President of Hong Kong Society of Ophthalmic Plastic and Reconstructive Surgery (HKSOPRS), Secretary of the Asia-Pacific Society of Ophthalmic Plastic and Reconstructive Surgery (APSOPRS).
Non-thyroid related, non-infectious orbital and eyelid inflammation involves a broad spectrum of conditions ranging from idiopathic, systemic, and specific causes of orbital and periocular inflammation to rarer conditions, e.g., Tolosa-Hunt syndrome and acute mucocutaneous syndromes including pyoderma gangrenosum, Stevens-Johnson syndrome, and toxic epidermal necrosis.
Idiopathic orbital inflammation (IOI) or idiopathic orbital inflammatory disease (IOID), previously known as orbital pseudotumor, is the commonest cause of non-thyroid related, non-infectious orbital and lid inflammation. Diagnosis of IOI is by exclusion of infectious, systemic, or specific etiologies, e.g., autoimmune thyroid disease, IgG4-related disease, sarcoidosis, histiocytosis, granulomatosis with polyangiitis (Wegener’s granulomatosis), Crohn’s disease, systemic lupus erythematosus, giant cell arteritis, Churg-Strauss syndrome, and other connective tissue diseases systemic evaluation, blood tests (serum thyroid function, ANA, ANCA, ACE, IgG4) and other ancillary investigations, e.g., chest radiographs [1, 2]. Histopathological examination of involved tissues is recommended to establish the diagnosis of IOI and to classify specific subtypes, e.g., sclerosing IOI, IOI with tissue eosinophilia . Congenital lesions, e.g., ruptured dermoid cysts and lymphangiomas, are differential diagnoses of pediatric IOID. On the other hand, neoplastic conditions e.g. extrascleral extension of retinoblastoma, choroidal melanoma, lymphoproliferative disease in adult, and primary or metastatic orbital tumors, e.g., rhabdomyosarcoma in children, and vascular lesions e.g. carotid-cavernous fistula, acute hemorrhage or thrombosis of pre-existing venolymphatic malformation may have inflammatory presentations mimicking IOI .
Orbital biopsy is often performed after orbital imaging  (computerized tomography or magnetic resonance imaging) rule out primary vascular lesion, to identify the extent (localized versus generalized) of involvement, tissue(s) affected (eyelids/preseptal tissues, extraocular muscle, lacrimal gland, sclera/Tenon, optic nerve sheath, orbital apex), nature (vascularity, cystic, abscess, calcification, bony), and any extraorbital extent (sinus, intracranial, infratemporal fossa) of the lesion(s). Surgical approach is chosen using the most direct route to the most accessible (usually the anterior-most portion) and least risky part of the lesion(s), taken into account of the surgeons’ experience. For more anterior-located or palpable lesions, upper lid crease, subbrow, subciliary skin incision, or caruncular, tarsal or forniceal conjunctival incision is usually enough for exposure . For deeper lesions, subperiosteal approach using transcaruncular incision in medial-based lesions , upper lid crease incision for superiorly and laterally located lesion , and inferior forniceal conjunctival or swinging-eye incisions  are preferred. Endonasal transethmoidal approach, with or without retraction of the medial rectus, is an evolving alternative for medial lesions . Small, apical lesions may require combined lateral orbitotomy with marginotomy , transcaruncular medial orbitotomy with retraction of the nearby rectus muscle, and occasionally even craniotomy approach to achieve adequate exposure.
Tissues obtained should be sent for histological and preferably microbiological examination while subsequent immunohistochemical, electron microscopic examination and other special stainings will be performed based on the initial hematoxylin and eosin staining results. Intraoperative frozen section examination allows rapid confirmation of adequate and representative sampling and is useful in more complicated or previously treated cases or biopsied.
In selected cases with suspected or confirmed orbital inflammation, surgical debulking of the lesion, preserving essential structures may improve proptosis and associated mass effects, e.g. mechanical ptosis, periocular swelling, compressive optic neuropathy, congestive orbitopathy (pain, redness and swelling), and exposure keratopathy. Mombaerts et al. reported 80 % (37 of 46) of patients with idiopathic dacryoadenitis fully recovered clinically after deliberately large debulking of the orbital lobe and injection of 40–80 mg triamcinolone to the remaining lacrimal gland . All patients were off systemic steroid shortly postoperatively. The authors suggested, with mechanism not well understood, the affected lacrimal gland(s) patients with idiopathic dacryoadenitis was both diagnostic, and often therapeutic appeared superior to systemic steroid with higher response, lower recurrence and treatment-related complication rates .