The imploding antrum: An unusual case of nontraumatic painless enophthalmos.

The imploding antrum or silent sinus syndrome is a rare phenomenon that presents with spontaneous painless enophthalmos and hypoglobus. It occurs due to ipsilateral maxillary antral atelectasis secondary to asymptomatic obstructive chronic sinus mucosal disease. Ophthalmologists, otorhinolaryngologists, and radiologists must be aware of this entity.