Subconjunctival orbital fat prolapse: an unsuspecting rare lesion

Subconjunctival orbital fat prolapse has been rarely described in the literature, often leading to misdiagnosis. In this article, we present the clinical features and treatment of patients with subconjunctival orbital fat prolapse as experienced in our clinic.

Cases of subconjunctival orbital fat prolapse were evaluated retrospectively from the records of the Zhongshan Ophthalmic Center at Sun Yat-sen University for the period of January 1, 1991 to December 31, 2010.

A total of 46 patients (33 males and 13 females) with subconjunctival orbital fat prolapse were identified. Their ages ranged from 44.0 to 82.0 years (mean age, 65.8 y). The right eye was involved in 16 cases, the left eye was involved in 11 cases, and both eyes were involved in 19 cases. Subconjunctival fat prolapse appeared as a soft, mobile yellowish mass, quite different from conjunctival dermolipoma, which presents as a congenital soft or firm pinkish-white or pinkish-yellow mass with hairs on the surface. The conjunctival fat prolapse was located in the superotemporal quadrant in 45 patients and in the superonasal quadrant in the remaining patient with no history of trauma or previous eye surgery in all the patients. Forty patients underwent surgical excision of the prolapsed fat and fixation of Tenon's capsule to the sclera. There were no recurrences of orbital fat prolapse or surgical complications in these patients with a mean follow-up of 2.4 years.

Subconjunctival orbital fat prolapse is a rare benign entity and can be easily diagnosed when this condition is considered. The surgical management usually has an excellent therapeutic outcome.