A 50 y.o. male presents with chemosis of the R eye.
He has a hx of TTP treated with steroids resulting in avascular necrosis of both hips with bilateral hip replacements and Grave’s disease sp RAI now on thyroid replacement.,
He has not responded to steroids. What does he have?
Our patient has chemosis and proptosis caused by thyroid eye disease. Hyperthyoidism causes enlargement of the thyroid by increasing IGF-1R( insulin like growth factor 1) leading to a complicated cascade causing fibroblast growth and increase in thyroid tissue. It also has side effects on many other tissues including the fatty tissues of the orbit.
IGF-1 in thyroid eye disease
Insulin-like growth factor 1 (IGF-1) receptors are proteins found on the surface of human cells responsible for growth of cells when activated by IGF-1. which is similar to insulin. They are responsible for overgrowth of cells in conditions like acromegaly and Grave’s disease.
There are a broad range of tumors which are associated with increased expression of IGF-1R; including breast, colon, lung, prostate, thyroid and myeloma. Many clinical trials have been conducted with IGF-1R receptor blockers but several early studies were suspended because of fatal toxicities. Recently, a use has been found for IGF-1R receptor blockers in treating thyroid eye disease.
Tepezza was approved in 2020 to treat thyroid eye disease by It blocking IGF-1R preventing cell proliferation. It is injected every three weeks for five months. Complications of tepezza include hyperglycemia, fatigue, reactivation of inflammatory bowel disease and hearing problems. There is currently a class action lawsuit in patients taking tepezza who have hearing loss.
Romana’s sign in Chagas disease causes orbital swelling
Chemosis is edema of the conjunctiva from the Greek words cheme and –osis meaning cockleshell due to the swollen conjunctive resembling the gelatinous inside of a cockleshell and -osis meaning condition. Swelling is due to exudate from capillaries. Anything that causes swelling can cause chemosis with the . most common causes of chemosis being allergies and viral infections.
CAUSES OF CHEMOSIS
PROPTOSIS- Things that cause proptosis lead to edema of the conjunctiva: hyperthyroidism, carotid-cavernous fistula, SVC obstruction, and cavernous sinus thrombosis all cause chemosis
INFECTION- Bacterial orbital cellulitis, gonorrhea, trichinosis, Chagas, mucor viral infections, dacrocystis all cause chemosis
GLAUCOMA- causes increased eye pressure
ALLERGIC REACTIONS- angioedema and seasonal allergies
TOXINS- mace(phenacyl chloride) and spitting cobra venom to the eye
Our patient underwent a conjunctival biopsy which did not show evidence of infection and was started on an increased dose of thyroid hormone at 175mcg/day and Tepezza,.
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