Which symptom in the context of a blowout fracture suggests potential traumatic compressive optic neuropathy?

In the context of a blowout fracture, pupillary dysfunction accompanied by decreased visual acuity is particularly indicative of potential traumatic compressive optic neuropathy. This condition arises when the optic nerve is compromised, often due to increased pressure or trauma, which can occur in the orbital area during such fractures.

Pupillary dysfunction may present as a relative afferent pupillary defect, where the affected eye does not constrict as strongly in response to light as the unaffected eye. This response is directly related to the optic nerve's function. Additionally, decreased visual acuity reflects the impaired nerve transmission, suggesting significant optic nerve involvement. Collectively, these symptoms provide critical insights into the severity of the injury and the potential for long-term vision problems.

Other symptoms, such as blurred vision or increased sensitivity to light, while potentially concerning, do not specifically indicate optic nerve damage or dysfunction. Redness in the eye may signal inflammation or external injury but lacks the direct association with the optic nerve's integrity. Thus, the combination of pupillary dysfunction and decreased visual acuity serves as a clear clinical marker of traumatic compressive optic neuropathy.