Nepal Eye Hospital offers advanced Electrophysiology of Vision (EPV) services using internationally recognized systems from Microvision, France. These tests provide objective, non-invasive assessment of visual pathway function, from the retina to the visual cortex.
Electrophysiological tests are essential for early diagnosis, differential diagnosis, and monitoring of retinal, optic nerve, and neuro-ophthalmic disorders—especially when clinical examination alone is inconclusive.
Our Electrophysiology Systems
Monopack One ERG • VEP • EOG
(Microvision, France)
Monopack One electrophysiology systems are designed in accordance with ISCEV standards, ensuring accurate, reliable, and reproducible results for both adult and pediatric patients.
Key Advantages of Microvision EPV Systems
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ISCEV-compliant protocols
Standardized testing for consistent and clinically reliable interpretation. -
Non-invasive and patient-safe
No radiation or injections involved. -
High signal quality and reproducibility
Essential for disease diagnosis and long-term follow-up. -
Suitable for adults and children
Including patients unable to cooperate with subjective vision tests. -
Objective functional assessment
Measures visual function beyond structural imaging.
Core Electrophysiology Tests & Applications
1. ERG – Electroretinography
ERG evaluates the functional integrity of the retina, including photoreceptors, bipolar cells, and inner retinal layers.
Clinical Applications
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Inherited retinal dystrophies (e.g., retinitis pigmentosa)
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Cone and rod dysfunction
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Unexplained visual loss
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Drug toxicity monitoring (e.g., hydroxychloroquine)
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Pediatric retinal disorders
2. VEP – Visual Evoked Potential
VEP measures the electrical response of the visual cortex following visual stimulation, assessing the functional integrity of the optic nerve and visual pathways.
Clinical Applications
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Optic nerve disorders
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Optic neuritis
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Multiple sclerosis-related visual pathway involvement
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Amblyopia assessment
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Delayed visual maturation in children
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Evaluation of visual function in non-cooperative patients
3. EOG – Electro-oculography
EOG evaluates the function of the retinal pigment epithelium (RPE) and its interaction with photoreceptors.
Clinical Applications
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Best vitelliform macular dystrophy
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RPE dysfunction
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Differentiation of macular dystrophies
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Evaluation of unexplained macular disease
Role of Electrophysiology in Modern Eye Care
Electrophysiological testing complements imaging modalities such as OCT and fundus photography by providing functional information, helping clinicians:
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Confirm diagnosis when structural findings are unclear
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Differentiate retinal vs optic nerve pathology
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Assess disease severity and prognosis
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Monitor disease progression and treatment response
Who Should Undergo Electrophysiology Testing?
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Patients with unexplained vision loss
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Suspected retinal dystrophies
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Optic nerve and neuro-ophthalmic disorders
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Pediatric patients with poor visual response
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Patients on long-term retinal toxic medications
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Medico-legal and disability assessment cases
