THEORIES to explain the occurrence of hyphema following cataract extraction have suggested a low ascorbic acid content, trauma from the dressing of the eye, blepharospasm, rupture of the new-formed capillaries of the wound and hemorrhage from an iridectomy. The usually accepted explanation of postoperative hemorrhage is rupture of newformed capillaries in the healing wound. The fact that these hemorrhages often occur at night on the third or fourth postoperative day, when the least trauma is being exerted, and often in the most cooperative and placid patients, does not make this explanation of the hyphema entirely satisfactory.
Hyphema rarely occurs if a preliminary iridectomy has been done. The incidence in several published series is reduced from 10 or 12 to 2 or 3 per cent if a preliminary iridectomy has been performed. Yet the wound healing and the rupture of the capillaries in these wounds would be comparable if no iridectomy