Retinal neovascular markers in retinopathy of prematurity: Aetiological implications

Aim: (1) To determine if expression of the blood-tissue barrier associated glucose transporter GLUT1 is preserved by the neovasculature of retinopathy of prematurity (ROP), in contrast with the reported loss of GLUT1 expression in preretinal vessels of proliferative diabetic retinopathy. (2) To compare the vascular immunophenotype of ROP to juvenile haemangioma, another perinatal neovascular disorder that has recently been shown to express placental type vascular antigens, including GLUT1 and Lewis Y antigen. Methods: A retrospective case report was carried out. Immunoreactivities for GLUT1 and Lewis Y antigen were assessed in a human eye with stage 3 ROP and compared with those in a control (paediatric) eye. The presence or absence of endothelial GLUT1 and Lewis Y immunoreactivity was determined in preretinal and intraretinal vessels. Results: Immunoreactivity was positive for GLUT1 and negative for Lewis Y in the intraretinal and preretinal neovasculature of the ROP affected eye and in the normal retinal vessels of the control eye. Conclusions: Retention of immunoreactivity for GLUT1 distinguishes ROP from proliferative diabetic retinopothy. Furthermore, absence of Lewis Y antigen co-expression distinguishes ROP from juvenile haemangioma, a perinatal form of GLUT1 positive neovascularisation that has recently been linked to placental vasculature.