Orbital Fat Prolapse

Orbital fat prolapse is produced due to extrusion of intraconal (inside the extra-ocular muscle cone) orbital fat beneath the conjunctiva.

 Steatoblepharon is due to prolapse of orbital fat into the eyelids. It is a common finding and is generally related to the ageing process. The fat pockets present around the muscle cone in the orbits bulge forward behind the lax orbital septum.

Orbital fat Prolapse is different from steatoblepharon and presents as a subconjunctival mass rather than a swelling of the eyelid. It may be unilateral or bilateral and is related to

• Eyelid surgery.
• Trauma.
• Generalised elastosis (cutis laxa).
• Idiopathic (most common).

Orbital fat prolapse may protrude through dehiscence in Tenon’s capsule or may extend into the hood of Tenon’s capsule. It extends along extra-ocular muscle to its insertion on the sclera. Mostly it is due to ageing as is seen in older adults, but it may be seen in children as well.

References

Dutton Jonathan J, Gayre Gregg S, Proia Alan D. Diagnostic Atlas of Common Eyelid Diseases. Informa Healthcare, Taylor & Francis Group, LLC 2007. P 91- 92.

Roy Hampton, Fraunfelder Frederick W, Fraunfelder Frederick T, Tindall Renee, Jensvold Bree. Roy and Fraunfelder’s Current Ocular Therapy Sixth Edition. Saunders Elsevier 2008. P 458.

Roy Frederick Hampton, Tindall Renee. Master Techniques in Ophthalmic Surgery Second Edition. Jaypee Brothers Medical Publishers (P) Ltd. 2015. P 401- 406.

Basak Samar K. Atlas of Clinical Ophthalmology Second Edition. Jaypee Brothers Medical Publishers (P) Ltd. 2013. P 425.

Bowling Brad. Kanski’s Clinical Ophthalmology- A Systematic Approach Eighth Edition. Elsevier 2016. P 56.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4583104/

https://jamanetwork.com/journals/jamaophthalmology/article-abstract/640456

http://onlinelibrary.wiley.com/doi/10.1111/aos.12032/pdf

Patient usually presents for cosmetic reason.

Symptoms may include

Swelling beneath bulbar conjunctiva.

Very large lesions lifting the upper eyelid may cause dryness of eyes or formation of Dellen.

Patient usually does not have symptoms like pain or inflammation.

Mostly orbital fat prolapse is due to ageing as is seen in older adults, but it may be seen in children as well.

It may be unilateral or bilateral and is related to

• Eyelid surgery.
• Trauma.
• Cutis laxa (Generalised elastosis).
• Idiopathic (most common).

Hypertrophic type of Blepharochalasis may also be associated with orbital fat prolapse.

Orbital fat prolapse may protrude through dehiscence in Tenon’s capsule or may extend into the hood of Tenon’s capsule. It extends along extra-ocular muscle to its insertion on the sclera. 

Diagnosis is clinical.

Orbital fat prolapse is seen most commonly supero-temporally where it protrudes beneath the palpebral lobe of lacrimal gland. It is seen as soft yellowish-white fat lobule beneath the bulbar conjunctiva, adjacent to lateral rectus muscle, or sometimes over it.

Small lesions may not normally be visible and are seen only when the upper eyelid is pulled upwards. Thus, patient may not even be aware of its presence.

Larger lesions may be visible within palpebral fissure.

Very large lesions may lead to corneal dryness or may lead to Dellen formation.

This condition may be unilateral or bilateral.

Lesions usually do not require any treatment.

Treatment is indicated for cosmetic reasons or when lesion is producing symptoms such as corneal exposure and dryness.

Treatment is surgical by which protruding portion of orbital fat prolapse is removed through conjunctival incision.