Retrobulbar Neuritis Due to Cyst of Sphenoid Sinus

Abstract

It seems beyond doubt that retrobulbar neuritis may arise as a result of local, I space-filling or inflammatory lesions. In this connection the aetiological role of ethmoid and sphenoid sinusitis has been a disputed subject. According to Benedict (1933), Lemoine (1938), and Duke-Elder (1940) the reason is the exaggerated enthusiasm with which, despite negative X-ray findings, many cases of retrobulbar neuritis were previously submitted to operations on the nasal sinuses as this was found to improve the condition. It was not remembered that, as Duke-Elder writes, “most of these cases recover spontaneously whether operated on or not, so that if every case were operated upon the cures would be about 90%. Moreover many of the cases thus considered ‘cured’ have developed disseminated sclerosis at a later date… It is rare for cases of optic neuritis to be associated with serious sinus disease.” All authors appear to be agreed on the latter point. Among 225 cases of retrobulbar neuritis Benedict found only one of rhinogenic aetiology. On the other hand, there is also a consensus of opinion regarding the significance of pressure upon the optic nerve: “It cannot be too often reiterated that any pressure on an optic nerve may produce a loss of vision with a central scotoma …” (Werner 1945). Benedict stresses the significance of tumours and cysts along the course of the nerve, and Letchworth (1932) also points out that a pus-filled sphenoid sinus may give rise to incarceration of the nerve in the optic foramen, especially if the latter is small.