Abstract
Abstract: :
Purpose: To determine the composition of the vitreous cloud emanating from subretinal hemorrhage. Methods: Biopsy specimens of the vitreous cloud were collected from 8 patients at the start of a pars plana vitrectomy. In 4 patients the cloud emanated from subretinal blood associated with age-related macular degeneration. In 4 other patients, the cloud emanated from preretinal hemorrhage associated with proliferative diabetic retinopathy. The duration of the vitreous cloud varied from 1 to 12 months. In the eyes in which the source of the cloud was subretinal blood, the retinal surface overlying the hemorrhage was examined with 20x ocular of the surgical microscope for retinal breaks. Results: Light microscopy of specimens of the vitreous cloud emanating from subretinal hemorrhage revealed erythrocyte fragments. No retinal breaks were found. The cellular contents of vitreous hemorrhage due to preretinal hemorrhage varied with the duration of hemorrhage, and consisted of normal erythrocytes, acanthocytes and ghost cells as well as fragments. Conclusion: Breakthrough of subretinal blood occurs by passive diffusion of fragments of erythrocytes across an intact internal limiting membrane. This is analogous to an earlier study in the rabbit model.
Keywords: 629 vitreous • 554 retina