To the Editor.
—Meningiomas of the sphenoid ridge may produce unilateral exophthalmos through direct orbital invasion, hyperostosis and loss of orbital volume, venous congestion, or a combination of these mechanisms.' Orbital invasion with minimal hyperostosis may involve extraocular muscles or simulate rectus muscle enlargement, producing a computed tomographic (CT) appearance resembling that seen in Graves' disease. An example of this condition is illustrated by the following case report.
Report of a Case.
—In August 1984, a 42-year-old woman complained of fullness of the right upper eyelid. Visual acuity was 20/20 OD and 20/20 OS, but there was mild unilateral elevation of intraocular pressure in the right eye and a question of right exophthalmos. Visual fields showed mild, generalized constriction in the right eye. The patient had a history of severe allergies to contrast dyes, and a CT scan of the orbits, performed without contrast medium, was