Walsh & Hoyt: Compressive Optic Neuropathies without Optic Disc Swelling (Retrobulbar Compressive Optic Neuropathies)

The importance of early diagnosis of compressive lesions that affect the retrobulbar portions of the optic nerve and do not cause optic disc swelling cannot be overemphasized. Early decompression of the optic nerves or chiasm may result in significant return of visual function, whereas misdiagnosis may result in progressive visual failure and irreversible visual loss, neurologic dysfunction, or death. Unfortunately, intracranial, intracanalicular, and occasionally, posterior orbital compressive lesions, usually do not produce disc swelling or significant neurologic or systemic manifestations. Thus, by the time such lesions cause visible optic pallor, significant damage to the optic nerve has often already occurred, preventing return of visual function even with otherwise successful decompression. The physician managing a patient with unexplained unilateral visual loss therefore must be aware of the characteristic history and early findings in patients with a retrobulbar compressive optic neuropathy.