title: [The cup/disc ratio in twins--a study of C/D ratio heredity].
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D009887:Ophthalmoscopy; D009898:Optic Disk / Q000033:anatomy & histology*; D009900:Optic Nerve / Q000033:anatomy & histology*; D014427:Twins