On fundus examination, the left optic disc head showed segmental bow-tie atrophy nasally and temporally, accompanied by an abnormally high horizontal cup-disc ratio of 0.8 (vertical cup-disc ratio = 0.5) (Figure, A). The nasal rim was particularly thinned and showed complete loss of the nerve fiber layer. In contrast, the superior and inferior disc rim segments appeared comparably thick and pink with clearly visible superior and inferior nerve fiber layers and striations. Likewise, the right optic disc showed an increased horizontal cup-disc ratio of 0.8, although the vertical cup-disc ratio was also increased (0.65), giving rise to a more concentric cup compared with the horizontal oval cup of the left eye (Figure, B). As in the left eye, the right optic rim was thinnest nasally. His intraocular pressures have never been elevated on repeated measurements during more than 2 years, ranging between 13 and 17 mm Hg on Pulsair tonometry (Keeler Ltd, Windsor, England) and 10 mm Hg on Goldmann applanation tonometry in each eye.