Why does orbital fat prolapse?

Have you ever seen a blob of pinkish-yellow tissue sag into view, when you pull upward on your upper eyelids? If you have ever seen this looking into the mirror, no need to worry. But how does this happen? Let’s look at the anatomy of the protective layers of the eye. We have the conjunctiva (the white part), the epi-sclera and the sclera (these both are a clear protective sheath that overlies the conjunctiva. Tenon’s capsule is another layer hidden behind your eyelids that also protect the globe of your eye. You cannot see Tenon’s capsule while looking in the mirror. The Tenon’s capsule functions to complete envelope the whole globe, running from the limbus (the part just beyond your cornea) all the way back to the optic nerve, which is in the back of eye. The fascia (or connective tissue within the Tenon’s capsule) is perforated by ciliary nerves, blood vessels and also by the extraocular muscles. These perforations is why orbital fat prolapses in some people. Although the globe is surrounded by orbit fat, it doesn’t penetrate under the layers of the eye because Tenon’s capsule keeps it out. Orbital fat sneaks under Tenon’s when there is a discontinuity of the capsule, such as when ciliary nerves, blood vessels and the muscles exist. Consider it a weakness in that protective Tenon’s capsule. One common way that a prolapse will occur is after eye surgery, such as strabismus and scleral buckle surgeries. In both of these surgeries, Tenon’s capsule is compromised. This happens isn’t actually a complication of surgery, it simply happens because Tenon’s capsule becomes thin and fragile with age, and small breaks in the fascia occur.

Surgical correction is performed mostly for cosmetic reasons. Most patients who have prolapse of the orbit fat are older than 50, since it’s mostly associated with a thinning and more fragile capsule seen as a result of aging. When you see the orbital fat on your temporal (closer to your temple) side of your conjunctiva, the first thing you may think of is that you have a tumor or a cancerous growth. But, this is simply not the case. The surgical correction involves a needle to numb the tissue surrounding the eye, an incision to remove the fat and cautery and sutures to close the wound. If you think you may have this in either of your eyes, please contact your optometrist or ophthalmologist to discuss your best plan for removal.