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Outcome Measure	Recommended Tests	Vision Prostheses	Gene Therapy	Stem Cells
Visual acuity	Visual acuity testing methodologies will vary with acuity levels, as follows: For patients with a letter chart visual acuity better than logMAR 1.60 (1/40, 0.025, 6/240, 20/800), we recommend the ETDRS high-contrast acuity chart. For patients with a letter chart visual acuity worse than logMAR 1.60 (1/40, 0.025, 6/240, 20/800), simpler test tasks, such as single letter acuity and grating acuity, should be used, such as the BRVT or FrACT. If no visual acuity measurements can be made, tests of light perception, location, or projection can be used, such as BaLM or BRVT.	X	X	X
Electrophysiology	ISCEV standard electrophysiology tests (available here: https://iscev.wildapricot.org/standards). Note that the FST has not yet been documented in an ISCEV standard but is a recommended test to quantify retinal sensitivity in patients with poor fixation or ULV.	X	X	X
Electrically evoked device effectiveness	The minimum testing or device effectiveness in a vision prosthesis should include the following: Phosphene threshold—Single phosphene detection thresholds using 0.5-s pulse trains Phosphene discrimination—A measure or indication of the ability to discriminate phosphenes from one another Phosphene field—A measure or indication of the spatial extent of the visual field that is occupied by elicited phosphenes	X
Vision processing	Reports of vision processing algorithms should include the following: A list of all sensors and input stream modalities that contribute to the appearance of the display or to delivered electrical stimulation (e.g., RGB/grayscale images, contrast, motion/inertial measurements) The spatial and temporal resolution of the input capture device when it is a possible limiting factor on the device display The size of the sampling window, stated as a ratio of the input to display (i.e., the physical display area) viewing angles when the input stream provides spatial coverage of the visualized scene The focal length and depth of focus of the lens through which light passes to the visual capture device, as well as any adjustability of these properties and any other properties of the lens that may significantly impact perception	X
Activities of daily living	Validated activity of daily living assessments for use in vision restoration trials include the following: Functional Low-Vision Observer Rated Assessment (FLORA) Very Low Vision Instrumental Activities of Daily Living (IADL-VLV) Picture recognition and visually guided navigation tasks (Rubin) Note that the choice of which tool to use may depend on the goals of the particular technology, and a customized assessment may be required. If so, this should be developed using the principles outlined in this guidance document.	X	X	X
Orientation and mobility	Basic assessment of orientation should include the following: Detection of the location of a standard source of light (windows, ceiling, or wall lights) Detection of the location of a door (real or simulated) against a contrasting wall Detection of moving people Following a contrasting line on the ground	X	X	X
Patient reported outcomes	PRO selection will depend on the population being assessed and, in particular, the level of vision that they have at baseline. The PRO selected should have been validated, calibrated, and, if possible, assessed using Rasch analysis. A list of possible PROs is provided in the main document and could include the following: For low vision, National Eye Institute Visual Function Questionnaire (NEI VFQ); Impact of Vision Impairment (IVI) For ultra-low vision, Ultra-Low Vision Visual Functioning Questionnaire (ULV-VFQ); Impact of Vision Impairment for Very Low Vision (IVI-VLV)	X	X	X
Psychosocial assessments	Psychosocial assessments should include the following: A trained mental health practitioner must be involved in the initial screening and decision-making process of all prospective participants in experimental clinical trials of these types. The comprehensive mental health screening must include an assessment of factors relevant to the potential participant's adjustment to blindness and their current quality of life as a person living with blindness. A trained mental health practitioner must be involved in the assessment of all participants throughout the duration of the trial. The trained practitioner should not only assess changes in the individuals emotional functioning and adjustment to gains or losses in visual acuity but also assist the participant in gaining an understanding of complex information that is relevant to the trial. Involvement of the potential participant in an early stage of the planning of a trial can significantly benefit the process of informed consent.	X	X	X