The earliest observable defect in glaucoma?
D000328:Adult; D005260:Female; D005654:Fundus Oculi / Q000473:pathology; D005901:Glaucoma / Q000175:diagnosis*; D006801:Humans; D007429:Intraocular Pressure; D009900:Optic Nerve / Q000473:pathology; D012160:Retina / Q000473:pathology; D013997:Time Factors