Association between ocular injuries and internal orbital fractures

Purpose: The physical mechanism of orbital blowout fractures has been debated for years by surgeons. Three main theories have been promulgated, including the hydraulic theory, the contact of globe-to-orbital wall theory, and the bone buckling theory. One might anticipate a strong association of blowout fractures and traumatically induced ocular injuries with the hydraulic and globe-to-wall theories because in both, the force is delivered directly to the ocular globe. This study was performed to assess the association between orbital blowout fractures and ocular injuries. Patients and Methods: Records of patients with orbital blowout fractures were collected from a single hospital. Those with complete records that included a thorough ophthalmologic examination were collected, and information about the nature of the injury to the bone and the ocular globe was tabulated. Results: A total of 225 patients ranging in age from 13 to 98 years (mean, 34.9 yr) who had sustained 240 blowout fractures (15 were bilateral) met the inclusion criteria. In all, 53 fractures (22%) involved ocular injuries that were thought to be directly associated with ocular trauma. The most common positive ocular finding was commotio retinae, which was present in 21 of 60 globes with significant traumatic ocular findings. This was followed in frequency by traumatic mydriasis (19 globes) and traumatic iritis (15 globes). Most ocular injuries were minor. Conclusions: The low incidence of significant ocular injury may indicate that direct contact of the globe with the traumatic force is not common. This finding gives credence to the buckling theory of blowout fracture, which seems more likely in most cases. (C) 2007 American Association of Oral and Maxillofacial Surgeons.