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The full-field electroretinogram (ffERG) is a specialized electrophysiologic test of retinal function in response to a full-field light stimulus. There are 6 standard protocols for isolating the electrical activity from the rods and cones. The ffERG is a valuable tool for objectively diagnosing and monitoring retinal disease. This activity reviews the ffERG procedure and technique and highlights the role of the interprofessional team in improving care for patients using this procedure. Objectives: Identify the indications for ffERG. Describe the typical ffERG findings associated with rod-cone dystrophy. Review the interfering factors of the ffERG. Explain the importance of collaboration and communication amongst the interprofessional team to enhance the delivery of care for patients affected by retinal disease using ffERG. Access free multiple choice questions on this topic.

The full-field electroretinogram (ffERG) is an ophthalmologic test that provides non-invasive objective quantitative measures of the electrical activity in the retina. The ffERG represents an electrical response from the retina to a flash of light and measures global retinal function.[1] Analysis of the ffERG waveform components can provide useful diagnostic information for distinguishing various retinal diseases, especially when the etiology of vision loss remains unclear following standard ophthalmologic clinical examination.

The ffERG is a non-invasive test with minimal risks. Patients may experience mild ocular discomfort during the procedure or, in very rare cases, develop a corneal abrasion depending on the type of electrode used. Interfering Factors Deviating from standardized testing conditions (i.e., lighting, flash intensity, recording environment, duration of light or dark adaptation, and pupil size) Electrode-based artifacts including poor contact with skin or cornea, incorrect placement, unstable position, and high electrical impedance Eye movement or blinking Uncorrected refractive errors Reduced electrical response with aging Ocular media opacification Diurnal fluctuation Response depression with anesthesia Variability in recordings between different device types[4]

The retina is a complex, neurosensory structure, and patients with retinal disease often present with non-specific visual symptoms. Therefore, determining the etiology of retinal disease by layer and by region is a frequent diagnostic challenge, and an interprofessional team approach is critical for providing appropriate patient care. Patients with sudden onset vision loss are typically encountered in the emergency department. Nurses are likely the first point of contact, who then triage the patient according to symptom acuity and severity. Given the ambiguity in clinical diagnosis and concern for emergent neurologic conditions, physicians and nursing staff routinely order a costly workup involving a battery of tests, the majority of which return negative. In turn, patients are instructed to follow up with an outpatient ophthalmologist. In most cases, these are comprehensive ophthalmologists, who then perform a standard eye examination, including ocular imaging. Notably, however, these diagnostic tests detect structural changes associated with ocular pathology, which do not always correlate with clinical findings. Consequently, patients may be misdiagnosed as having a benign condition and, in some cases, presumed to be malingering. Neuro-ophthalmology is the field that is commonly acknowledged when the etiology of vision impairment remains unknown, despite extensive medical workup.[14] [Level 4] Considering a broad differential is important to distinguish retinal dysfunction from alternative, similar appearing causes since the choice of therapy depends on the underlying etiology of the disease process. Electrophysiology, in combination with other clinical findings, offers invaluable data to assist the members of the interprofessional team and provides effective patient care while minimizing unnecessary tests. Clear communication and care coordination between nurses, physicians, ophthalmologists, as well as ophthalmology subspecialists are critical for establishing a correct diagnosis and proceeding with proper management thereafter. [Level V]