Variation of visual evoked potential delay to stimulation of central, nasal, and temporal regions of the macula in optic neuritis

Introduction: Optic neuritis is an inflammation of the optic nerve that usually affects young females. In Western countries, natural history and treatment of optic neuritis(ON) has been studied extensively. However aetiology, natural history, clinical features of ON and their relation to multiple sclerosis in Asian population needs to be defined yet. Methods: 30 patients who were diagnosed as optic neuritis were included between June 2013 to December 2014 at BP Koirala Lions Centre for Ophthalmic Studies (BPKLCOS). A detailed history was obtained followed by examination of anterior and posterior segment. Assessment of visual acuity, color vision, contrast sensitivity, visual evoked potential (VEP),visual field and MRI of orbit and brain was done in all cases. All patients were treated with intravenous Methylprednisolone 500mg twice daily for 3 days followed by oral steroid for 11 days which was tapered in the next 4 days.The patients were reassessed at 2 weeks, 1 month and 3months. Results: Commonest presenting symptom was diminution of vision(65%). MRI showed multiple paraventricular oval plaques definite of multiple sclerosis in one patient and one was diagnosed as probable MS who had a single periventricular plaque. Visual evoked potential (VEP) showed increase in the mean P100 latency at 60’ and reduction in amplitude in eyes affected with optic neuritis compared to normal eyes. At 3 months follow up, 70% had good visual recovery (>6/18). The cause of non-improvement in vision was disc pallor. Optic disc pallor was detected in 37.5% of the eyes during follow up. Conclusions: Good visual recovery was observed in most eyes with acute optic neuritis. Multiple sclerosis was seen in 1 patient who had recurrent optic neuritis.

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Multifocal visual evoked potential evaluation for diagnosis of acute optic neuritis and for prediction of visual outcome and ganglion cell layer thinning following optic neuritis

Multiple Sclerosis Journal ◽

10.1177/1352458520975732 ◽

2020 ◽

pp. 135245852097573

Author(s):

Gorm Pihl-Jensen ◽

Benedikte Wanscher ◽

Jette Lautrup Frederiksen

Keyword(s):

Optic Neuritis ◽

Ganglion Cell ◽

Visual Function ◽

Visual Evoked Potential ◽

Evoked Potential ◽

Conduction Block ◽

Visual Outcome ◽

Multifocal Visual Evoked Potential ◽

Visual Evoked

Background:: While damage to the optic nerve following optic neuritis (ON) is readily quantifiable, the evaluation of prognosis for visual function and neuroaxonal loss in the acute ON is challenging. Objective:: The objective of this study is to investigate the value of multifocal visual evoked potential (mfVEP) in acute ON, diagnostically for acute ON and prognostically for visual outcome and subsequent ganglion cell/inner plexiform layer thickness (GCLIPLt). Methods:: A prospective cohort study of mfVEP and full-field visual evoked potential (ffVEP) in acute, unilateral ON (onset < 31 days) was conducted. Comparisons with healthy controls ( n = 30) and association analysis with follow-up optical coherence tomography (OCT) measurements (of the GCLIPLt) and visual function (Sloan low-contrast visual acuity (LCVA)) were conducted. Results:: Seventy-nine ON patients were included (mean: 17 days from onset). Excluding measurements with conduction block, ffVEP ( n = 54) and mfVEP ( n = 44) showed sensitivities of 89% and 84% to a specificity of 97%. 65/79 patients were re-examined (mean: 200 days follow-up). mfVEP amplitude and latency inter-eye asymmetry in acute ON correlated with GCLIPLt ( r = 0.587 and Spearman’s ρ = 0.597, for both, p < 0.001). mfVEP amplitude correlated with LCVA inter-eye asymmetry at follow-up ( r = 0.421, p < 0.001), mfVEP latency did not. Conclusion: mfVEP may support the prognostic evaluation of acute ON patients and prove valuable in future neuroprotective and remyelinating trials. In acute ON, the increase in diagnostic value of mfVEP to ffVEP may be limited due to widespread conduction block.

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Implantation of Stimulation Electrodes in the Subretinal Space to Demonstrate Cortical Responses in Yucatan Minipig in the Course of Visual Prosthesis Development

European Journal of Ophthalmology ◽

10.1177/112067210501500413 ◽

2005 ◽

Vol 15 (4) ◽

pp. 493-499 ◽

Cited By ~ 24

Author(s):

H.G. Sachs ◽

F. Gekeler ◽

H. Schwahn ◽

W. Jakob ◽

M. Köhler ◽

...

Keyword(s):

Visual Evoked Potential ◽

Evoked Potential ◽

Point Of View ◽

Visual Prosthesis ◽

Subretinal Space ◽

Electrode Arrays ◽

Cortical Responses ◽

Stimulation Electrode ◽

Stimulation Of ◽

Visual Evoked

Purpose During the course of the development of visual prostheses, subretinal stimulation films were implanted in micropigs in order to prove the feasibility of subretinal electrical stimulation with subsequent cortical response. One aim was to demonstrate that epidural recording of visual evoked potentials is possible in the micropig. Methods Film-bound stimulation electrode arrays were placed in the subretinal space of micropigs. This enabled the retina to be stimulated subretinally. Since conventional visual evoked potential (VEP) measuring is virtually impossible in the pig from the neurosurgical point of view, epidural recording electrode arrays were positioned over the visual cortex as permanent electrodes. Results The feasibility of temporary implantation of film-bound stimulation electrode arrays was successfully demonstrated in the micropig model. On stimulation with monopolar voltage pulses (1000 to 3000 mV), reproducible epidural VEP measurements (5 to 10 μV) were detected. Conclusions The feasibility of subretinal stimulation of the retina was demonstrated in a retinal model that is similar to the human retina. This animal model therefore offers a suitable means of studying the tolerability of stimulation situations in the course of visual prosthesis development.

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