Aftobetin-HCl and Fluorescence Detection Measured by Sapphire II to Determine the Number and Timing of Administrations

Open label study. 45-105 subjects will be enrolled. Subjects will undergo the following procedures: * Complete physical and neurologic examination (Screening) * Neuropsychological testing (Screening) * Ophthalmologic examination (Screening and Visit 4 (Safety follow up visit)) * Administration of ointment - 3 administrations (Visit 1) * Sapphire II Fluorescent Eye Measurements (Visits 1-3): Prior to first administration of ointment and then 24 +/- 2 hours, 28 +/- 30 minutes and 48 +/- 2 hours following first ointment administration * Amyvid Positron Emission Tomography (PET) Amyloid Scan (only required for MCI and mild AD subjects who have not had a positive amyloid PET scan in the last 3 years) Subjects will also be asked to participate in an elective second Sapphire II assessment to assess its reproducibility. Repeatability testing is optional and will require a separate consent. Subjects will come back for Visits 5-9 (ointment administration and eye scans and a follow up safety assessment).