Retinopathy of Prematurity in Anencephaly:Pathological and Immunohistochemical Studies of Six Eyes from Three Female Stillborn Holoanencephalic Infants

Abstract

Retinopathy of prematurity (ROP), a disease of developing blood vessels, is seen predominantly in premature infants requiring oxygen administration. We have noted various degrees of ROP in 6 eyes from 3 female stillborn holoanencephalic babies. Their gestational ages ranged from 30 to 35 weeks. All 6 eyes showed marked hypoplasia of the ganglion cell layer, the nerve fiber layer, and the optic nerve head. At the junction of vascularized and avascular anterior retina, proliferation of vanguard spindle cells (in 4 eyes from 2 cases) and of rear guard angioblastic cells (in all 6 eyes) were noted. Intravitreal vascular proliferation (in 3 eyes from 2 cases) and partial retinal detachment with vitreous hemorrhage (in 1 eye) were also seen. Immunohistochemical studies revealed positive staining for 5-100 protein and negative staining for laminin & Ulex aeropaeus in spindle cells (2/2 cases); the reversed pattern in angioblastic cells (3/3 cases). The reduced mass of retina generally lacking intact ganglion cells and their axons in our cases may induce local vasoconstriction in response to tissue hyperoxia, which result in the retinal hypoxia and consequently, provide the impetus for the establishment of neovascularization. The immunohistochemical findings lend support to the neuroglial origin of the vanguard spindle cells.