The Ultrastructure of Bruch's Membrane

Abstract
Although Bruch's membrane has been studied by many investigators,1-10details of its structure have rarely been included in reports of electron microscopic and physiologic studies of the retina and choroid.11-24The membrane's fine structure has been described in the human,13,17,23,24cat,14frog,21and turtle,22but none of these reports has indicated the exact portion of the choroid examined. For this reason a systematic examination of Bruch's membrane was undertaken. The posterior, equatorial, and peripheral zones were studied in human and animal eyes, and a special study was made of the macular area of human eyes. This last will be reported in a subsequent paper in this series. Materials and Methods The human material consisted of normal areas of eyes removed because of malignant melanoma. Soon after removal the eyes were bisected and most of the vitreous was removed. The tissue was immersed in cold,