Subconjunctival fat prolapse

Subconjunctival fat prolapse is an acquired herniation of intraconal fat due to the weakening of the Tenon capsule by normal aging, surgery, or trauma. It presents clinically with a fat-containing epibulbar mass in the lateral canthal area.

Epidemiology 

Subconjunctival fat prolapse occurs mainly in elderly obese men with a mean age of 65 years (range 41-85 years).

Clinical presentation

They mostly present as unilateral or bilateral soft yellow colour mass with a convex anterior margin and superficial fine blood vessels in the superotemporal quadrant or lateral canthus region, around the rectus muscle and below the lacrimal gland. It can be easily pushed back into the orbit with a cotton tip applicator and becomes more prominent by retropulsion of the globe.

Radiographic features

Although rarely clinicians request imaging for further investigation of thisthese lesions, both CT and MRI would demonstrate invariable continuation of these lesions with intraconal fat.

Treatment and prognosis

Usually, reassurance would be enough if there isare no visual problems and no cosmetic concern exist.  

Differential diagnosis

Sometimes differentiation of subconjunctival fat prolapse from other entities is difficult clinically and because treatment and outcome are quite different radiological and ultimately histopathological confirmation is required for final diagnosis: 

• dermolipoma
• liposarcoma 
• limbal dermoid