scholarly journals Electrophysiological markers of preclinical diagnosis of glaucomatous optic neuropathy

2021 ◽  
Vol 14 (1) ◽  
pp. 35-41
Author(s):  
M. O. Kirillova ◽  
M. V. Zueva ◽  
I. V. Tsapenko ◽  
A. N. Zhuravleva
Keyword(s):  
Optic Neuropathy ◽  
Ganglion Cells ◽  
Open Angle Glaucoma ◽  
Statistical Significance ◽  
Photopic Negative Response ◽  
Glaucomatous Optic Neuropathy ◽  
Functional Changes ◽  
Bright Flash ◽  
Pattern Size ◽  
Group 2

Purpose: to evaluate the changes in electrophysiological indicators reflecting various aspects of the function of retinal ganglion cells (RGC) and their axons in the early diagnosis of glaucomatous optic neuropathy (GON).Material and methods. Two clinical groups, (1) 35 patients (60 eyes) aged 49 to 70 with suspected glaucoma and (2) 16 patients (30 eyes) aged 43–68 with initial primary open-angle glaucoma (POAG), and a comparison group of 38 relatively healthy subjects (45 eyes) aged 42–70 were tested for pattern-reversed visual evoked potentials (PVEP), transient and stationary pattern-ERGs (PERG) according to ISCEV, and photopic negative response (PhNR).Results. The P100 amplitudes in both clinical groups differed significantly from the norm in PVEP on small and large patterns. The elongation of peak latency (T) of P100 compared with norm was significant for the stimulus 1° in group 2. In both groups of patients, increased variability of the temporal parameters of PERG and PVEP for small patterns was found. In groups 1 and 2, a decrease in the amplitude of P50 and N95 peaks of transient PERG for all stimuli was revealed, which was the most significant for the 0.3° pattern. In group 1, the N95 peak was significantly delayed in PERG for large patterns. A statistically significant reduction in the steady-state PERG's amplitude was found in the groups of suspected glaucoma and initial POAG. The sharpest changes were found for small (0.8° and 0.3°) patterns. The elongation of T compared to the norm was most pronounced for PERG at 0.3°, but due to the high variability of temporary indicators within the group, it had no statistical significance. The amplitude of PhNR was significantly different from the norm in the ERG for a flash of 3.0 cd·sec/m2.Conclusion. In patients with suspected glaucoma, a decrease in the P100 VEP amplitude with the simultaneous elongation of T may be considered as a criteria for the plastic stage at the level of lateral geniculate nucleus. Markers of functional changes in RGCs are the decrease in the amplitude of PhNR in response to bright flash, and P50 and N95 of PERG for pattern size 0.3°. The results indicate a greater vulnerability of the parvocellular system to early events in the development of GON.

Modern methods for assessing morphometric and functional indicators in primary glaucoma

2021 ◽  
pp. 83-87
Author(s):  
N.R. Sharvadze ◽  
◽  
A.L. Shtilerman ◽  
D.P. Skachkov ◽  
Y.A. Drovnyak ◽  
...  
Keyword(s):  
Open Angle Glaucoma ◽  
Diagnostic Methods ◽  
High Tech ◽  
Glaucomatous Optic Neuropathy ◽  
Static Perimetry ◽  
Functional Changes ◽  
Modern Methods ◽  
Analytical Review ◽  
Primary Glaucoma ◽  
Key Words Glaucoma

In the article are presented analytical review of scientific articles devoted to the study of modern methods of diagnostics of primary glaucoma. On the basis of scientific articles, a review material was collected and systematized on diagnostic methods for studying morphometric and functional changes in primary glaucoma, which are used in modern ophthalmic practice. In recent years, the improvement and implementation of new high-tech modern diagnostic methods open up new opportunities for researchers and clinicians. Optical coherence tomography, OCT angiography, static perimetry make it possible, by comparing morphometric and functional parameters, to give a more complete, comprehensive assessment of pathological changes in the optic nerve head, in the macular region and at the level of the choriocapillaries. Prevention of glaucoma blindness largely depends on its early diagnosis based on the use of modern organizational and medical technologies. Key words: glaucoma, open-angle glaucoma, intraocular pressure, glaucomatous optic neuropathy, diagnostic methods.

scholarly journals Glaucoma: A Degenerative Optic Neuropathy Related to Neuroinflammation?

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 535 ◽  
Author(s):  
Stéphane Mélik Parsadaniantz ◽  
Annabelle Réaux-le Goazigo ◽  
Anaïs Sapienza ◽  
Christophe Habas ◽  
Christophe Baudouin
Keyword(s):  
Optic Neuropathy ◽  
Ganglion Cells ◽  
Public Health Problem ◽  
Visual Pathways ◽  
Glaucomatous Optic Neuropathy ◽  
Major Public Health Problem ◽  
Retinal Ganglion ◽  
Current Therapies ◽  
Retinal Structure ◽  
Immunomodulatory Therapies

Glaucoma is one of the leading causes of irreversible blindness in the world and remains a major public health problem. To date, incomplete knowledge of this disease’s pathophysiology has resulted in current therapies (pharmaceutical or surgical) unfortunately having only a slowing effect on disease progression. Recent research suggests that glaucomatous optic neuropathy is a disease that shares common neuroinflammatory mechanisms with “classical” neurodegenerative pathologies. In addition to the death of retinal ganglion cells (RGCs), neuroinflammation appears to be a key element in the progression and spread of this disease. Indeed, early reactivity of glial cells has been observed in the retina, but also in the central visual pathways of glaucoma patients and in preclinical models of ocular hypertension. Moreover, neuronal lesions are not limited to retinal structure, but also occur in central visual pathways. This review summarizes and puts into perspective the experimental and clinical data obtained to date to highlight the need to develop neuroprotective and immunomodulatory therapies to prevent blindness in glaucoma patients.

The Photopic Negative Response evaluation in patients with Leber's hereditary optic neuropathy

2021 ◽  
pp. 216-219
Author(s):  
M.S. Shmelkova ◽  
◽  
N.L. Sheremet ◽  
I.A. Ronzina ◽  
N.A. Andreeva ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Retinal Ganglion Cells ◽  
Optic Neuropathy ◽  
Ganglion Cells ◽  
Negative Response ◽  
Photopic Negative Response ◽  
Control Group ◽  
Retinal Ganglion ◽  
Leber's Hereditary Optic Neuropathy ◽  
Hereditary Optic Neuropathy

Purpose. To assess the retinal ganglion cells function in patients with Leber's hereditary optic neuropathy (LHON) by registering the photopic negative response (PhNR) while the photopic electroretinography is performed. Material and methods. 14 patients with different LHON mutations and 9 healthy individuals were examined. A standard ophtalmological examination was performed, including visual fields, spectral optical coherence tomography, photopic electroretinography and PhNR tests. Results. Significant differences in the PhNR latency (68.4±4.01/64.28±5.37, p<0,01) and the PhNR amplitude (21.5±9.34/32.72±12.73, p<0,003) were revealed in patients with LHON and the control group. The study revealed significant differences between the PhNR latency (р<0.01) and the PhNR amplitude (р<0.008) in patients with visual acuity (VA) ≤ 0.1 and the control group, and between the PhNR amplitude in patients with VA≥0.13 and the control group (р<0.05). There were found significant correlations between the PhNR parameters and visual acuity, mean sensitivity, RNFL and GCC thickness. A strong positive correlation was found between the PhNR amplitude and the GCC thickness in patients with VA≥0.3. Conclusion. The PhNR parameters reflect the retinal ganglion cells function in patients with LHON and correlate with RNFL and GCC structural changes. Key words: Leber hereditary optic neuropathy, mitochondrial optical neuropathies, retinal ganglion cell, photopic negative response, PhNR.

Reduction of Intraocular Pressure and Glaucoma Progression

2020 ◽  
pp. 79-84
Author(s):  
Alan D. Penman ◽  
Kimberly W. Crowder ◽  
William M. Watkins
Keyword(s):  
Intraocular Pressure ◽  
Optic Neuropathy ◽  
Open Angle Glaucoma ◽  
Controlled Clinical Trial ◽  
Glaucomatous Optic Neuropathy ◽  
Delayed Treatment ◽  
Lowering Therapy ◽  
Risk Of Progression ◽  
Modest Reduction

The Early Manifest Glaucoma Trial (EMGT) was a randomized, placebo-controlled clinical trial in patients with newly detected, previously untreated, primary open-angle glaucoma (POAG) to determine whether immediate institution of intraocular pressure (IOP)–lowering therapy reduces the risk of progression compared to delayed treatment or observation. The study showed that IOP-lowering therapy offered a definitive benefit in patients with early glaucoma by delaying progression of glaucomatous optic neuropathy, especially in eyes with higher IOPs (>21 mm Hg) at baseline. Even modest reduction in IOP decreased the risk of progression. However, a large percentage of treated eyes still showed progression during follow-up. The progression of glaucomatous optic neuropathy was highly variable and difficult to predict for an individual patient.

scholarly journals The photopic negative response (PhNR): measurement approaches and utility in glaucoma

2020 ◽  
Vol 40 (12) ◽  
pp. 3565-3576
Author(s):  
Matteo Prencipe ◽  
Tommaso Perossini ◽  
Giampaolo Brancoli ◽  
Mario Perossini
Keyword(s):  
Optic Neuropathy ◽  
Negative Response ◽  
Photopic Negative Response ◽  
Diagnostic Process ◽  
Glaucomatous Optic Neuropathy ◽  
Specific Information ◽  
Automated Perimetry ◽  
Pattern Erg ◽  
Glaucomatous Damage ◽  
Additional Tool

Abstract Purpose Visual electrophysiological testing continues to generate interest among glaucoma experts because of its potential help in clarifying disease pathophysiology and promoting early detection of glaucomatous damage. The photopic negative response (PhNR) is a slow negative component of the full-field electroretinogram that has been shown to provide specific information about retinal ganglion cells (RGCs) activity. The purpose of this article is to review the literature to explore the currently available measurement methods and the utility of PhNR in glaucoma diagnostic process. Methods We gathered publications related to the origins, types of stimuli used, measurements methods and applications of the PhNR of ERG in animal models and humans through a search of the literature cited in PubMed. Search terms were: “PhNR”, “photopic negative response”, “glaucoma”, “glaucomatous optic neuropathy”, “ERG”, “electroretinogram”. Results The most reliable PhNR measurements are obtained using a red stimulus on a blue background, without requiring refractive correction, fixation monitoring, or ocular media transparency. Given its direct correlation with RGCs response, the PhNR measured as baseline-to-trough (BT) represents the most reliable parameter of evaluation. Glaucoma patients with evident perimetric defects show pathologic PhNR values. Even though the PhNR is promising in detecting early RGCs impairment, distinguishing between healthy subjects and suspect patients at risk of developing glaucomatous damage still remains challenging. Conclusion The PhNR is a useful additional tool to explore disorders that affect the innermost retina, including glaucoma and other forms of optic neuropathy. In particular, comparing reports of the standard examinations (optic disc assessment, OCT RNFL measurement, standard automated perimetry) with the results of electrophysiological tests may be helpful in solving clinical diagnostic and management dilemmas. On the one hand, the PhNR of the ERG can examine the parvocellular pathways; on the other hand, the steady-state pattern ERG optimized for glaucoma screening (PERGLA) can explore the magnocellular pathways. This could give ophthalmologists a useful feedback to identify early RGCs alterations suggestive of glaucoma, stratify the risk and potentially monitor disease progression.

scholarly journals Facilities of diagnosis and monitoring of optic neuropathy in primary open-angle glaucoma. Part 2

2020 ◽  
Vol 13 (1) ◽  
pp. 85-93
Author(s):  
O. A. Kiseleva ◽  
N. V. Balatskaya ◽  
A. M. Bessmertny ◽  
L. V. Yakubova ◽  
V. I. Kotelin
Keyword(s):  
Early Diagnosis ◽  
Optic Neuropathy ◽  
Primary Open Angle Glaucoma ◽  
Open Angle Glaucoma ◽  
Glaucomatous Optic Neuropathy ◽  
Open Angle ◽  
Clinical Endpoints ◽  
Modern Methods

The first part of the review was focused on modern methods of instrumental diagnostics of primary open-angle glaucoma [1]. Diagnostic possibilities and informativeness of objective measurable parameters were discussed with regard to special criteria, called clinical endpoints. The second part of the review is dedicated to finding methods of early diagnosis and criteria of the progression of glaucomatous optic neuropathy.

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