To the Editor: The medical mystery in the October 12 issue1involved a 31-year-old woman who presented with a sudden onsetof an inferonasal visual-field deficit in the left eye. Twodays earlier, she had traveled for 16 hours by air. On physicalexamination the day after the onset of her visual symptoms,ophthalmoscopy revealed a band of opacification in the leftmacula that was diagnostic of a branch retinal artery occlusion,as shown on fluorescein angiography (Figure 1A). The patienthad digital erythema, cyanosis (Figure 1B), and severe clubbing(Figure 1C) of the . . . [Full Text of this Article]