Supplementary Material for: Temporal protrusion of the optic disc implicated in central visual field abnormalities in high myopia: Two case reports

Introduction: Severe central visual field defects are frequently observed in eyes with high myopia. We report the clinical features of two patients each with a central visual field defect; they had high myopia with an extreme protrusion in the temporal part of the optic disc. This unique optic disc appearance has not been reported previously.
Case presentation: In 2 patients, a 54-year-old man and a 65-year-old woman, each was diagnosed with high myopia in the left eye with outward protruding of the optic disc toward the macula. Swept-source optical coherence tomography revealed a focal lamina cribrosa defect at the temporal edge of the protruding optic disc corresponding to the papillomacular bundle area of retinal nerve fiber, which was thin around the focal lamina cribrosa defect. Visual field examination showed a central visual field defect in the eye, whose pattern corresponded to the papillomacular bundle responsible area.
Conclusion: The development of a protrusion in the temporal part of the optic disc may result in a focal lamina cribrosa defect, and cause a central visual field defect in eyes with high myopia. A temporal protrusion of the optic disc may be an important risk factor for central visual field defects.