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In this paper, technical details of visual evoked potentials (VEP) assessment and pattern electroretinography (PERG) are reviewed. Both methods are used to perform an objective functional examination of visual channels and to clarify the level, at which they have been damaged. Contributions of parvo- (P), magno- (M) and koniocellular (K) systems to the morphology of PERG and VEP responses are discussed with account to test conditions, selectively supportive of the activity of particular cell populations. The review analyzes the physiological role of such stimulation parameters as brightness and color contrast of the pattern elements as well as spatial and temporal frequency in detecting dysfunction of color channels and mistuning of the P- and M- pathways. Different times taken for neuronal integration and signal conduction along the M- and P- pathways determine the timing of the P- and M- VEP components, allowing us to judge their contribution to VEP morphology from the same recording.

Based on the analysis of the data of a multifocal electroretinography FOK response and the retinal thickness in 38 patients with suspected glaucoma, the paper shows the inhibition of the external retinal biopotential and the lower retinal thickness in the posterior ocular pole. There is a correlation of these changes with light sensitivity alterations, as evidenced by quadrant analysis. It is stressed that monitoring of patients with suspected glaucoma must comprise a morphofunctional assessment using the current techniques.

The paper considers the possibilities of using multifocal electroretinography (mfERG) to examine patients with primary glaucoma. Forty-seven patients underwent mfERG that established that as the disease progressed, there were reductions in the mfERG wave amplitude, when the first flash response, and in biopotential density, when the quadrant analysis was made. Biopotential changes in glaucoma can be analyzed in relation to the first flash response and a pattern response. Monitoring of changes in primary glaucoma may use mfERG.

The paper describes the first experience in using multifocal electroretinography (mfERG) in patients with antiphospholipid syndrome (APS). In the latter, thrombogenesis is mosaic in most cases so the techniques providing a spatial imaging of the pathological process is of interest in the examination of patients with this disease. These techniques include mfERG. The quadrant mfERG analysis that reveals pathological changes in relation to the vascular involvement area is of the greatest informative value in patients with APS-associated retinal vascular occlusions.

The paper gives the results of electroretinography (ERG) in 38 patients (73 eyes) with type 2 diabetes mellitus at different stages of diabetic retinopathy (including in diabetic macular edema). The reductions in the macular ERG (M-ERG) amplitude parameters and in the retinal density of bioelectrical activity and the decreased amplitude and longer latency of multifocal ERG (mfERG) N1 and P1 components evidence the involvement of the retinal macular region into the pathological process and the magnitude of these changes depends on the presence of imaged macular edema. Despite the certain limitations of mfERG, assessment of the topography of retinal bioelectrical activity in the central field of vision is an important supplement to M-ERG results and may be a prognostic criterion for the development of a pathological process and its extent.

On the basis of the ISCEV standards and the author's experience, the paper describes theoretical prerequisites for multifocal electroretinography and its methodology. The variants of assessing the results, failure causes, and terminology of multifocal analysis of electroretionographic evidence are considered.

The paper presents a procedure and conditions for recording multifocal electroretinogram (mfERG), its origin, and factors influencing small-signal ERG. The optimal conditions of ERG extraction using the existing method are appraised and indications for its use in ophthalmological care defined. The results of comparing the new types of electrodes developed in Russia for ERG recording and a DTL electrode included in the ISCEV guidelines are presented.

The paper presents the results of using the current multifocal studies of visual functions in patients with various diseases of the retina (detachment, tapetoretinal abiotrophy, macular foramen). It provides evidence for the high correlation of changes detectable in these patients by statistical computer-assisted perimetry and multifocal electroretinography. The implication of comprehensive application of these techniques to the diagnosis and differential diagnosis of ocular neurosensory apparatus diseases and to the functional monitoring and evaluation of treatment has been ascertained.

The paper gives the results of electroretinographic and psychophysical studies in hypertensive patients with first-, second-, and third-degree blood pressure (BP) elevation. The most characteristic functional symptoms of hypertensive retinopathy were defined at different stages of its development. There may be impaired retinal bioelectrical activity and diminished contrast and color sensitivity both in the presence and absence of ophthalmoscopically visible changes. Based on the findings, the authors have developed a functional classification of hypertensive retinopathy in relation to the degree of BP elevation.

The paper describes the current types of electroretinography, the origin of electric retinal activity and its role in the diagnosis, differential diagnosis, and monitoring of retinal diseases of various origin. It presents the electroretinographic symptoms typical of pathology of the retinal cone and rod system in some hereditary diseases whose genes have been mapped and cloned to date and whose pathogenesis specified. The current concepts of retinal remodeling in its dystrophic changes are produced and emphasis is laid on the necessity of using the progress of vision biology and physiology in ophthalmological practice.