Astrocytes and Müller cells play crucial structural and functional roles in maintenance of barrier function; thus, our finding that these cell types, unique within the retina, express Prdx6 is of obvious relevance to any disease where the blood-retinal barrier is compromised, such as diabetic retinopathy, exudative age-related macular degeneration and arterial and venous occlusions. Here, PRDX6 is linked to diabetic retinopathy.