PTPN5 and age-related macular degeneration: In this study, we analyzed age-related changes of STEP46 and STEP61 expression and activity in the retina of OXYS rats at the age of 20 days (the preclinical assay of AMD-like retinopathy) and at age 13 months (assessment of the progressive stage of disease) using age-matched Wistar rats as a control.