Exophthalmos (also known as proptosis) is the protrusion of one eye or both anteriorly out of the orbit. It derives from Greek, meaning 'bulging eyes. It occurs due to an increase in orbital contents in the regular anatomy of the bony orbit. Exophthalmos typically arises from an increase in orbital contents within the bony orbit, leading to forward displacement of the globe. The origin of the increased orbital content depends on the underlying cause. In Graves ophthalmopathy, enlargement of the extraocular muscles and expansion of the orbital adipose tissues occurs due to abnormal hyaluronic acid accumulation and edema collection into the retro-orbital space. 
The etiological basis of proptosis can include inflammatory, vascular, infectious, cystic, neoplastic (both benign and malignant, metastatic disease), and traumatic factors. Some examples include infectious causations such as orbital cellulitis and subperiosteal abscesses. Traumatic causations could be orbital emphysema, retro-orbital hemorrhage, and carotid-cavernous fistula. Vascular causations not traumatically related would be orbital arteriovenous malformation (AVM) varices and aneurysms. Neoplastic causations include adenocarcinoma of the lacrimal gland, pleomorphic adenoma of the lacrimal gland, meningioma, lymphoma, and metastatic disease.
A ruptured lymphangioma can enlarge after its rupture and sequestering of heme, which pathologically is described as a chocolate cyst. Orbital varices can result in proptosis with increased venous pressure in the orbit, as seen with a Valsalva maneuver or change in postural position.
Satyendra Dhar MD, @DharSaty
#Proptosis, #orbitaltumors, #orbitalinflammation, #orbitalinfection, #orbitalvascularanomalies #exophthalmos 
Satyendra Dhar, MD @DharSaty · 2 years ago
Hospital Medicine Assistant Clinical Professor Images on this website are 'NOT' a substitute for clinical judgment or Medical Advice. Opinions on this website are our own and do not represent the opinions of any affiliated institutions. Please don’t use this website for medical advice but instead consult with your healthcare provider. The images listed are solely intended for educational & informational purposes 'ONLY', to allow topics in Medicine to be explained in a compact & easy to comprehend manner. Images/graphic materials may have been taken from published research articles & Google images/Scholar. Although images are curated, there is no way to guarantee a consistent standard of accuracy & quality across the library of images. πŸ‘‰ Follow 'Medical Infographics' on πŸ‘‰ https://www.DharSaty.com
Related images