LAUSR

A woman in her 60s presented to the ophthalmology clinic with 10 months of blurred vision in her left eye. More recently, she noted that her left eye “drifts out at times.” She also reported drooping of the left upper eyelid and binocular, variable horizontal or vertical diplopia at distance. She also complained of itchy eyes but denied any pain or headaches. Her medical history includes breast cancer, diagnosed in 2000 and treated with lumpectomy and radiotherapy. A mammogram, completed 4 months before her ophthalmology visit, was reported as stable. On presentation, her visual acuity was 20/20 OD and 20/40 OS. She had slightly decreased color vision (8/10 Ishihara plates) of the left eye and there was no relative afferent pupillary defect. Confrontation visual fields were full. External examination revealed mild left proptosis and severely limited adduction of the left eye. Both optic nerves appeared normal on retinal examination. Magnetic resonance imaging of the brain (Figure 1) showed a 2.3-cm intraconal mass inseparable from the left lateral rectus muscle. The mass medially deviated the left optic nerve and conformed to the shape of the orbital globe with mild bony remodeling of the lateral orbital wall.