Neurovisual function in preterms: early marker for neuro-developmental risk?

Aim of the study: Research supports the importance of visual function and its crucial role in early neuromotor, cognitive, and emotional development. Recent literature data underline that visual function may be an indicator of neurological status of the subject and therefore, the finding of a significant visual impairment, can be a wake-up call for the possible presence of brain damage and therefore a neurological disability. The aim of this study was to evaluate visual function in term newborns and preterms through a clinical instrument called “NAVEG” (Neonatal Assessment Visual European Grid - specifically designed to assess visual function in newborns and infants) highlighting maturational differences and differences linked to the presence of suffering of the central nervous system, analyzing the visual profile with neurological and neuro-structural (cerebral ultrasound) data. Methods: Our clinical tool consists of an assessment grid of visual function in term infants and premature. NAVEG grid is made up of three main sections: Ocular Visual Component (OVC), Motor Visual Component (MVC), Perceptual Visual Component (PVC), which allow us to obtain a more detailed and complete analysis of visual function which could be related with different levels of involvement of the visual pathway (eye, optic radiation, occipital cortex, oculomotor functions). We evaluated the applicability of NAVEG in a group of 58 healthy term infants born between 37-42 GA, free of major diseases, recruited from the Division of Neonatology of the Civil Hospital of Brescia and 51 preterms with a gestational age ≤ 34 weeks, recruited from the NICU-Spedali Civili of Brescia. Results: NAVEG turned out to be a reproducible, easily administered, quick (average 10') and non-invasive tool. Our data have highlighted different profile features between the two groups in all components analyzed. Preterms show a different visual profile than term infants, particularly those with brain lesions. NAVEG showed a good discrimination power between healthy and pathological preterms in relationship to neurologic/neuroimaging data. The results have strengthened our hypothesis and encouraged us to propose the present study. Conclusion: The development of a method of evaluation of visual function in the neonatal period, with particular attention to those with higher risks, is therefore of utmost importance, as it may to lead to early diagnosis and therefore to implement a rehabilitation plan at a time where the child's brain shows the highest degree of plasticity. This would have a positive impact not only on functional vision outcome, but on all adaptive functions.