Normative Database for Pattern Electroretinogram (PERG) and Flash Electroretinogram (FERG)

Investigators plan to enroll 50 subjects at Wills Eye Hospital without any eye diseases.

Participants will undergo a complete eye examination to determine eligibility, including visual acuity testing, intraocular pressure (IOP) in millimeters of mercury (mmHG), and visual field (VF) testing.

Participants will then be tested with Diopsys NOVA™ PERG & FERG systems. For both tests, two electrodes are placed on the skin underneath each eye below the eyelashes. Participants' skin will be cleaned before electrodes are placed. A small amount of gel will be placed on skin where electrodes are placed for testing. Electrical responses are recorded with electrodes in response to visual stimuli.

Inclusion criteria

• Healthy volunteers age 18 years
• older with normal eye exam

Exclusion criteria

• spherical refraction outside + 5.0 Diopters and cylinder correction outside + 3.0 Diopters.
• IOP (intraocular pressure) ≥ 22 mm Hg (millimeters of mercury)
• history of any type of glaucoma in either eye.
• Intraocular surgery in study eye (except non-complicated cataract or refractive surgery performed more than 1 year before enrollment).
• Best corrected visual acuity worse than 20/40.
• Evidence of diabetic retinopathy, diabetic macular edema, or other vitreo-retinal disease in either eye.
• Evidence of optic nerve, macula and/or retinal nerve fiber layer abnormality in either eye.
• Evidence of reproducible (false positives, fixation losses and false negatives ≤ 25% with no observable testing artifacts).
• Standard Automatic Perimetry (SAP) abnormality in either eye, defined as Pattern Standard Deviation < 5% level, and/or abnormal Glaucoma Hemifield test result, and/or any other pattern of loss which is consistent with a neurologic and/or ocular disease.
• Current or recent (within the past 30 days) use of an agent (by any administering method) known to affect visual function.
• Inability to obtain reliable PERG/FERG (Pattern Electroretinogram/Flash Electroretinogram) results.