Neurophysiology of Vision and Neurophthalmology

OPERATIONAL RESEARCH UNIT
Neurophysiology of vision and neurophthalmology
Policlinico Universitario Campus Bio-Medico di Roma
Via Álvaro del Portillo n. 5 - 00128 Rome
Istituto Cesa, 1° floor, G.B. Bietti Foundation premises

Currently, laboratory activity mainly aims to identify the neurophysiopathological mechanisms that lead to vision loss in various pathologies, including glaucoma, optic neuritis from various demyelinating diseases, Alzheimer’s disease, and cerebral vascular pathologies.

Director: Prof. Vincenzo Parisi
Access to services
To make an appointment, call 06.22541633 on Wednesday mornings, exclusively for neurophthalmological disorders, then go to Via Álvaro del Portillo n. 5 - Istituto Cesa, 1° floor, on the premises of the G.B. Bietti Foundation.

Instrumental diagnostics
Measurement of visual acuity, ocular motility exam, colour perception, electrofunctional exams (flash ERG, focal ERG, PERG, PEV), manual and computerized campimetry, retinography, exophthalmometry, Hess screen test, OCT (Ocular Coherence Tomography) of the retina and fibres of the optic nerve.

Neurophysiology of vision studies the physiological mechanisms that make visual perception possible. It evaluates the complex mechanisms that transform light stimuli into electric stimuli and their transmission from the retinal photoreceptors to the visual cortex. It is currently possible to objectively evaluate the functionality of the structures that make up the optical path using electrofunctional methods, such as various types of electroretinograms (ERG) or by recording the variation in the bioelectric potential of the visual cortex (Visual Evoked Potential, VEP). The simultaneous recording of ERG and PEV makes it possible to obtain an index of nervous conduction between the retina and the visual cortex. Pathological modifications in the transmission of visual information from the retina’s photoreceptors to the cerebral cortex can lead to serious alterations in visual perception.
Using electrofunctional methods, whether or not associated with in vivo or in vitro morphological assessment methods, it is possible to identify the physiopathological mechanisms (in both animal models and humans) of many pathologies affecting the visual nervous system from the retina’s photoreceptors to the visual cortex.

Neurophthalmology studies the pathologies affecting the neuroretina and the portions of the brain (optic nerve, optic chiasm, optic tract, lateral geniculate nucleus, optic radiations, and occipital cerebral cortex) involved in the transmission and decoding of visual information. Some of the main pathologies that can induce – albeit with different aetiologies – pathological modifications in the nerve structures that make up cerebral visual pathways include diabetes, glaucoma, multiple sclerosis, cerebral vascular pathologies (TIA, stroke, cerebral infraction), Alzheimer’s disease, and neoplastic or hypophysiary cerebral, infective, or toxic pathologies affecting the optic nerve (optic neuritis) or other structures of the optic path. Many cerebral pathologies with an inflammatory, vascular, neoplastic, or toxic aetiology can induce other visual system dysfunctions that are not strictly associated with changes in visual perception. These dysfunctions can cause diplopia (paralytic strabismus), accommodative deficiencies, ptosis, or anomalies in pupillary diameter.

Currently, our main focus within the field of neurophthalmology and its clinical application is on the identification of the neurophysiopathological mechanisms that lead to deficiencies in visual perception in various pathologies that can affect the nervous system, and the possibility of identifying new treatment opportunities.