TPP1 and retinal degeneration: As such, the goals of the study were to (1) determine the feasibility and repeatability of commercially available segmentation software in quantitatively measuring retinal layers by anatomic zone in CLN2-associated retinal degeneration; (2) objectively capture the age at which significant parafoveal manifestations of the degeneration may occur; and (3) describe any age-associations of the degeneration in the inner and outer retinal layers.