RDP Reliability Study

The purpose of this study is to assess the reliability of the Optina Retinal Deep Phenotyping.TM(RDP) platform. The RDP Platform is comprised of the Optina-4CTM retinal camera and its Optina-4C ConnectTM software, as well as the Optina awAIrTM-CAS Test (also called CAS Test) for detecting phenotypic changes in the retina that are associated with cerebral beta-amyloid status (positive or negative). This study will quantify points of variability in the data input for the CAS Test, including:

• Left eye vs. right eye (retinal scan)
• Eye algorithm selection (eye assessment obtained from different eye specialists either an Ophthalmologist or an Optometrist)
• Hardware variability (Inter-instrument Variability retinal scans obtained from different Optina-4CTM cameras)
• Inter-operator variability (retinal scans obtained from different Users of the Optina-4CTM camera)
• Intra-operator variability (retinal scans obtained by the same user on the same Optina-4CTM camera

Inclusion criteria

• Male and female adults aged 50 years and older with vision in both eyes.
• Sufficient fluency in English or French to participate in study visits.
• Ability to give informed consent.
• Individuals with both eyes meet the eligibility criteria for retinal imaging.

Exclusion criteria

• Pupil dilation contraindicated (due to pathology, or presence of 3 quadrants with Van Herick grading of 0 or 1 without iridotomy).
• Inadequate pupil dilatation (< 6mm diameter) preventing uniform illumination of the retina with the Optina 4CTM camera.
• Diagnosis of glaucoma or signs of glaucoma (excavation ratio ≥0.7).
• Signs of vascular occlusion or retinopathy (microaneurysm, exudate, hemorrhage, or edema) within a diameter of 10 mm from the mid-point between the optic nerve head and the macula.
• Presence of drusen and/or age-related macular degeneration (AREDS 9-step scale

≥4 - cumulative drusen area diameter ≥ 250 µm, pigmentary changes and cumulative drusen area diameter ≥ 63 µm or pigmentary changes and cumulative geographic atrophy area diameter ≥ 354 µm).

• Nuclear sclerosis > 2 (LOCS II four-point grading system) or presence of central cortical or central posterior subcapsular cataract.
• Deficient visual fixation (inability to fixate for at least 2 s).
• Refractive error outside the range of -15 D to +15 D.
• Corneal or media opacities (e.g., Weiss ring) affecting retinal imaging on a cumulative area > 1 disc area within a diameter of 10 mm from the mid-point between the optic nerve head and the macula (i.e., the area of interest for the Optina 4CTM imaging)
• Scar, atrophy, naevus, tumor, epiretinal membrane or retinal pucker with a cumulative area > 1 disc area within a diameter of 10 mm from the mid-point between the optic nerve head and the macula.
• Papilledema and/or optic disc swelling.
• Macular anomaly (e.g., macular hole, dystrophy, degeneration).
• Inability to obtain up to 5 images or a minimum of 3 images of satisfactory quality with the Optina 4CTM per the Optina Diagnostics quality index software and /or per the eye specialists' evaluation. This exclusion criterion also applies if participants are unable to provide the required number of images during the second visit as well.
• Currently taking or has previously taken cerebral amyloid modifying medication.