Bilateral Visual Loss Caused by Pneumosinus Dilatans: Idiopathic Cases are not Always Reversible

To report a rare case of primary pneumosinus dilatans (PSD) and to specify the cardinal imaging findings associated with this condition.

A 20-year-old patient presented with bilateral profound visual loss as a result of primary PSD. A detailed review of clinical findings and presumed pathophysiological basis of vision loss was performed.

Other than undiagnosed primary hypothyroidism, no other abnormalities were found. With the diagnosis of PSD, the patient underwent optic nerve decompression through transnasal sphenoidotomy. However, after nine months of follow-up, no improvement in the patient’s vision was attained.

Unlike previous reports of favorable visual results after sphenoidotomy and bilateral decompression of the optic nerves, vision recovery was not achieved in this case.