An 18-month-old, female spayed domestic shorthair presented with a mass of the dorsal aspect of the right globe. The mass had been present since the owner adopted the cat as a stray, but was slowly enlarging. Oral and topical antibiotics had been given with no response. The mass was covered with conjunctiva and was slightly mobile on eyelid movement. An anterior axial incipient cortical cataract was also noted in the affected eye. The mass collapsed during fine-needle aspiration, and a clear fluid was removed. Moments later, the globe partially collapsed but in the next few minutes, the globe and mass returned to their normal size. Staphyloma, a thinned, stretched sclera with a lining of uveal tract, was diagnosed and corrected surgically. These lesions are either congenital or secondary to pathologic conditions of the sclera. Diagnosis is based on clinical appearance. In this case, ultrasonography was used to confirm the connection from the mass to the anterior chamber.

COMMENTARY: Staphylomas are rare in the cat and differentials should include emphysema, subconjunctival hemorrhage, and foreign body. Although less likely, other differentials include inflammation, infection, and neoplasia.

Staphyloma in a cat. Skorobohach BJ, Hendrix DVH. VET OPHTHALMOL 6:93-97, 2003.