CUMBERLAND, R.I.-The U.S. Food and Drug Administration has determined that the Biologic License Application conducted by Neurotech Pharmaceuticals Inc., for NT-501, an investigational encapsulated cell therapy for the treatment of MacTel, is sufficiently complete to permit a substantive review, according to an announcement from Neurotech. MacTel is a progressive, neurodegenerative disease of the retina that results in the deterioration of central vision, significantly impacting patients' quality of life. NT-501 is an ocular implant designed to deliver sustained therapeutic doses of ciliary neurotrophic factor directly to the retina to slow the progression of the disease, Neurotech said.