title: The retinal blood vessel patterns in twins.
mesh_terms: D004777:Environment; D005260:Female; D005823:Genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000098:blood supply; D011247:Pregnancy; D012171:Retinal Vessels / Q000033:anatomy & histology*; D014427:Twins; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic