Intravitreal ERT to Prevent Retinal Disease Progression in Children With CLN2

Inclusion Criteria: * Genotypic confirmation of classical CLN2 Batten's disease from a CLIA certified lab. * Enzyme level deficiency of tripeptidyl-peptidase * Minimum age requirement: 24 months of age at enrollment * Maximum age requirement: 72 months of age at enrollment * Currently receiving intraventricular cerliponase alfa * Willing to participate in the proposed study visits over the 2-year period * Minimum central retinal thickness (CRT) of 140μm based upon OCT assessment * Clear ocular media * No ocular pathology present to account for vision loss other than optic atrophy and pigmentary retinopathy that is felt to be due to the CLN2 disease process Exclusion Criteria: * Any opacities in the clear ocular media including vitreous debris. * History of ocular trauma or prior ocular surgery. * Episode of generalized motor status epilepticus within four weeks before the First Dose visit * Severe infection (e.g., upper respiratory tract infection, pneumonia, pyelonephritis, or meningitis) within four weeks before the First Dose visit (enrollment may be postponed) * Those with a history of bleeding disorders. * History of or current chemotherapy, radiotherapy or other immunosuppression therapy within the past 30 days (corticosteroid treatment may be permitted at the discretion of the PI) * Has a medical condition, or extenuating circumstance that, in the opinion of the investigator, might compromise the subject's ability to comply with the protocol required testing or procedures or compromise the subject's wellbeing, safety, or clinical interpretability