Dissociated Visual Development: Electrodiagnostic Studies in Infants Who Are ‘Slow to See’

Abstract

SUMMARY Four infants were studied who failed to show any visual interest or following responses in the first three months of life. Although no definite ocular abnormalities were found at the time of presentation, both the parents and their medical advisers initially had serious concerns about the infants' visual prognosis. Initial electroretinograms (ERG) were found to be unequivocally normal, but three of the infants showed absent or impaired cortical visual evoked responses (VER). The fourth infant had an initial VER which was immature. Subsequently, all the infants showed increasing visual responsiveness from three to four months of age and all now have visual behaviour and general development appropriate to their ages. The VERS were repeated after four months of age and all showed normal responses. It is concluded that poor or even absent VER responses in early infancy may not always indicate a poor prognosis for vision. The possible mechanisms of this visual maturational lag are discussed. RESUME Développement visuel dissocié: études électrodiagnostiques chez les nourrissons lents à voir Quatre nourrissons incapables de montrer un intérêt visuel ou de présenter des réponses de poursuite durant les trois premiers mois de la vie ont étéétudiés. Bien qu'aucune anomalie oculaire n'ait été trouvee au moment de la consultation, les parents, tout comme leurs conseillers medicaux, ont été initialement tres inquiets quant au pronostic de vision des nourrissons. Les premiers electroretinogrammes etaient indiscutablement normaux mais trois des nourrissons presentaient des reponses corticales visuelles absentes ou alterees. Chez le quatrieme nourrisson, la premiere reponse visuelle evoquee etait de type immature. Par la suite, tous les nourrissons ont presente un progres dans les reponses visuelles a partir de trois ou quatre mois d'age; actuellement tous les quatre ont un comportement visuel et un developpement general approprie pour leur age. Les reponses evoquees visuelles recherchees ulterieurement etaient normales. On peut conclure qu'une reponse visuelle evoquee pauvre ou meme absente, dans la premiere enfance, peut ne pas toujours indiquer un mauvais pronostic de vision. Les mecanismes possibles de ce delai de maturation visuelle sont discutes. ZUSAMMENFASSUNG Dissoziierte Entwicklung des Sehvermögens: Elektrodiagnostische Untersuchungen bei Säuglingen mil verzogerter Entwicklung des Sehvermogens Vier Kinder wurden untersucht, die in den ersten drei Lebensmonaten kein visuelles Interesse oder entsprechende Reaktionen gezeigt hatten. Obwohl zum Zeitpunkt der Untersuchung keine defmierten Storungen am Auge nachweisbar waren, hatten sowohl die Eltern als auch ihre medizinischen Berater anfanglich ernste Bedenken ob sich das Sehvermogen bei diesen Kindern normal entwickeln wiirde. Die ersten abgeleiteten Elektroretinogramme waren eindeutig normal, jedoch zeigten drei der Kinder keine oder nur geringe corticale visuelle Reaktionen. Die beim vierten Kind visuell evozierten Potentiale waren anfanglich nicht altersentspr...

Cerebral Visual Impairment in Children

“…birth before the 32nd gestation week, is considered a risk factor for the development of CVI, because maturation of the central visual system is delayed or because the post-chiasmatic components are injured, particularly at the subcortical level (Ball et al 2012 ), or both (so-called encephalopathy of prematurity), (Volpe 2009a ); or periventricular leucomalacia, (PVL), (Dutton and Jacobson 2001 ;Bassi et al 2008 ; see also Sect. Delayed development of attentional capacities or attentional dysfunctions may cause delayed maturation of vision (Mellor and Fielder 1980 ;Fielder et al 1985 ;Lambert et al 1989 ;Rose et al 2001 ). The consequences include homonymous visual fi eld (Jacobson et al 2006 ), lack of stereovision (Geldof et al 2014 ) and impaired movement vision (MacKay et al 2005 ), but mostly delayed development of visual functions and capacities and/or a variety of visual dysfunctions in the visual and oculomotor systems.…”

Delayed Visual Maturation: Ophthalmic and Neuro‐developmental Aspects

“…The visual deficit is complete and therefore greater than can be accounted for by a postnatal developmental lag, as the infant is less visually responsive than appropriate for a preterm neonate at about 30 to 32 weeks gestation. Certainly the visual defect is greater than can be accounted for by delayed foveal development (Mellor and Fielder 1980), and normal electroretinography precludes a more generalised retinal abnormality (Mellor and Fielder 1980, Harel et al 1983, Hoyt el al. 1983, Lambert et al 1989).…”

Delayed visual maturation in infants

“…[3] The term DVM was first suggested by Illingworth in 1961 when he described two infants with normal ocular examination who displayed visual unresponsiveness before the age of 6 months and who then became attentive to visual stimuli after this age. [4] DVM has previously been referred to as temporary visual inattention, la pseudo-atrophie optique des nouveau-nés, [3] papilla grisea, [7] myelogenesis retarda, [8] dissociated visual development, [8] and visual developmental delay. [5,6] Based on the presence or absence of associated abnormalities, Beauvieux considered DVM to exist in two forms.…”

“…[6,11] In contrast, several authors have described abnormal flash and pattern VEPs in infants with DVM. [8,9] Abnormalities of VEPs have included prolonged latencies, abnormal waveforms, and decreased amplitudes. Mellor reported an absence or delay of flash VEPs in four children with DVM.…”