Fig. 6. Vitreous pathology in retinopathy of prematurity. The lack of peripheral retinal development, most prominent temporally, results in abnormal secondary vitreous development in this region. Thus, there is liquid vitreous rather than gel in the peripheral fundus. The interface between the normal gel vitreous posteriorly and the liquid vitreous anteriorly causes instability with traction upon the ridge of cells from which new vessels proliferate. The proliferation and membrane formation follows the interface plane between the gel and liquid vitreous compartments, oriented toward the edge of the lens. Traction at the ridge stimulates further vessel proliferation, traction upon the peripheral retina, and ultimately hemorrhage and/or retinal detachment. *, lens; G, gel vitreous (posterior); L, liquid vitreous (anterior). (Courtesy of Maurice Landers, MD)