Innovative and non-invasive method for the diagnosis of dyschromatopsia and the re-education of the eyes

Objective Dyschromatopsia is a pathology that afflicts many people even if, in most cases, they are not aware of it. The pathology, in fact, is not disabling in everyday life even if it is limiting from some points of view. Once diagnosed, dyschromatopsia is generally not investigated further: it is not known exactly how it manifests itself and with what extent. Furthermore, since it is a genetic pathology, it is “condemned” not to be resolvable. Biological neural networks have shown the capability to readapt their structure in order to overcome sensory malfunctions or neuronal damage. We propose a diagnostic algorithm capable of qualitatively and quantitatively assessing the degree of visual impairment due to the presence of congenital or acquired dyschromatopsia. The algorithm can also be easily integrated for its possible therapeutic use. Methods The application of a novel approach based on an innovative algorithm for the diagnosis of dyschromatopsia and plastic reeducation training of the eye is proposed. Results Our algorithm provides an accurate measure of the degree of dyschromatopsia severity in patients quickly and noninvasively. In addition, it can be used for a reeducational training process. Conclusions Dyschromatopsia is an increasingly common disease in the world. The method we developed can diagnose dyschromatopsia. The algorithm also develops a metric scale for recognizing the degree of severity. The algorithm can be used independently by specilized and non-specilized people. In addition, the algorithm can be integrated with Machine Learning techniques to create a customized eye retrainer based on the plasticity and adaptability of neural tissue

The multiple sclerosis visual pathway cohort: understanding neurodegeneration in MS

BACKGROUND: Multiple Sclerosis (MS) is an immune-mediated disease of the Central Nervous System with two major underlying etiopathogenic processes: inflammation and neurodegeneration. The latter determines the prognosis of this disease. MS is the main cause of non-traumatic disability in middle-aged populations. FINDINGS: The MS-VisualPath Cohort was set up to study the neurodegenerative component of MS using advanced imaging techniques by focusing on analysis of the visual pathway in a middle-aged MS population in Barcelona, Spain. We started the recruitment of patients in the early phase of MS in 2010 and it remains permanently open. All patients undergo a complete neurological and ophthalmological examination including measurements of physical and disability (Expanded Disability Status Scale; Multiple Sclerosis Functional Composite and neuropsychological tests), disease activity (relapses) and visual function testing (visual acuity, color vision and visual field). The MS-VisualPath protocol also assesses the presence of anxiety and depressive symptoms (Hospital Anxiety and Depression Scale), general quality of life (SF-36) and visual quality of life (25-Item National Eye Institute Visual Function Questionnaire with the 10-Item Neuro-Ophthalmic Supplement). In addition, the imaging protocol includes both retinal (Optical Coherence Tomography and Wide-Field Fundus Imaging) and brain imaging (Magnetic Resonance Imaging). Finally, multifocal Visual Evoked Potentials are used to perform neurophysiological assessment of the visual pathway. DISCUSSION: The analysis of the visual pathway with advance imaging and electrophysilogical tools in parallel with clinical information will provide significant and new knowledge regarding neurodegeneration in MS and provide new clinical and imaging biomarkers to help monitor disease progression in these patients

ACUTE CENTRAL SEROUS CHORIORETINOPATHY: Factors Influencing Episode Duration.

To evaluate the influence of clinical and multimodal imaging parameters on the duration of acute central serous chorioretinopathy (CSCR) episodes. Consecutive patients with first, treatment-naïve central serous chorioretinopathy episodes presenting within 20 days of symptoms onset were prospectively included. They were reevaluated 15 days to 20 days later, followed by monthly evaluation for 6 months. Subfoveal choroidal thickness (SFCT), fluorescein leakage intensity on fluorescein angiography, elevation of retinal pigment epithelium (RPE) lesions at leakage sites, focal/multifocal pattern of indocyanine green angiography (ICGA) at baseline, time-dependent pattern of subretinal fluid (SRF) resorption on OCT using volume segmentation, history of corticosteroid intake and mean blood pressure were evaluated using univariate (Log rank test) and multivariate (Cox proportional hazard regression) survival analysis. Thirty-one patients were included (26 men, 5 women, mean age: 40.0 ± 8.9 years, range: 24-58), of which 26 (84%) had episode resolution by 6 months. Using univariate analysis, episode duration was longer in cases with subfoveal choroidal thickness ≥500 μm (P = 0.0002), retinal pigment epithelium elevation at leakage sites ≥50 μm (P = 0.033), and a peak in subretinal fluid observed during follow-up (P = 0.013), and there was a near-significant association of intense fluorescein leakage (P = 0.074) with longer episodes. Using multivariate analysis, subfoveal choroidal thickness ≥500 μm (P = 0.017), retinal pigment epithelium elevation at leakage sites ≥50 μm (P = 0.010) and patient age ≥40 years (P = 0.010) were significantly and independently associated to longer episodes. Indocyanine green angiography pattern, corticosteroid intake, and blood pressure did not influence episode duration. Older age, higher subfoveal choroidal thickness, and higher degree of retinal pigment epithelium alteration at leakage sites are independent factors of longer acute central serous chorioretinopathy episodes

Macular Microcysts in Mitochondrial Optic Neuropathies: Prevalence and Retinal Layer Thickness Measurements.

PurposeTo investigate the thickness of the retinal layers and to assess the prevalence of macular microcysts (MM) in the inner nuclear layer (INL) of patients with mitochondrial optic neuropathies (MON).MethodsAll patients with molecularly confirmed MON, i.e. Leber's Hereditary Optic Neuropathy (LHON) and Dominant Optic Atrophy (DOA), referred between 2010 and 2012 were enrolled. Eight patients with MM were compared with two control groups: MON patients without MM matched by age, peripapillary retinal nerve fiber layer (RNFL) thickness, and visual acuity, as well as age-matched controls. Retinal segmentation was performed using specific Optical coherence tomography (OCT) software (Carl Zeiss Meditec). Macular segmentation thickness values of the three groups were compared by one-way analysis of variance with Bonferroni post hoc corrections.ResultsMM were identified in 5/90 (5.6%) patients with LHON and 3/58 (5.2%) with DOA. The INL was thicker in patients with MON compared to controls regardless of the presence of MM [133.1±7μm vs 122.3±9μm in MM patients (p<0.01) and 128.5±8μm vs. 122.3±9μm in no-MM patients (p<0.05)], however the outer nuclear layer (ONL) was thicker in patients with MM (101.4±1mμ) compared to patients without MM [77.5±8mμ (p<0.001)] and controls [78.4±7mμ (p<0.001)]. ONL thickness did not significantly differ between patients without MM and controls.ConclusionThe prevalence of MM in MON is low (5-6%), but associated with ONL thickening. We speculate that in MON patients with MM, vitreo-retinal traction contributes to the thickening of ONL as well as to the production of cystic spaces

Choroidal Thickness in Nonarteritic Anterior Ischaemic Optic Neuropathy: A Study with Optical Coherence Tomography

Nonarteritic anterior ischemic optic neuropathy (NA-AION) is the most common nonglaucomatous optic neuropathy in adults over 50 years of age. It is usually related to cardiovascular risk factors. The primary objective of this study was to evaluate choroidal thickness in patients with chronic NA-AION, and the secondary objective was to evaluate macular thickness in these patients. This cross-sectional study compared two groups: group 1 included 20 eyes of 20 patients with chronic NA-AION, and group 2 included 31 eyes of 31 healthy controls. In both groups, the choroidal thickness was measured using the enhanced depth imaging program of Heidelberg Spectralis® optical coherence tomography (Heidelberg Engineering, Heidelberg, Germany). The macular thickness was also measured using the automatic software of the same device. The mean follow-up time after NA-AION in group 1 was 57.17 ± 26.92 months. The mean choroidal thickness of the posterior pole was 244.38 ± 61.03 µm in group 1 and 214.18 ± 65.97 µm in group 2 (p = 0.004). The mean macular thickness was higher in group 2. Macular thickness is reduced in eyes that had an episode of NA-AION, whereas choroidal thickness is generally higher in these eyes when compared with normal eyes. The increase in choroidal thickness may be due to a local dysfunction in vascular autoregulatory mechanisms, which may predispose to ischemic phenomena.info:eu-repo/semantics/publishedVersio

Dinámica Cerebral:La actividad cerebral en función de las condiciones dinámicas de la excitabilidad nerviosa. Tomo primero.

This book can be cited as: Gonzalo J. (1945/2010/2022), "Dinámica Cerebral", Tomo I, Consejo Superior de investigaciones Cientificas, Madrid 1945, in: "Dinámica Cerebral" facsimile edition, Gonzalo I. (Ed), Red Temática en Tecnologías de Computación Artificial/Natural, Universidad de Santiago de Compostela 2010 (Open Access http://dspace.usc.es/handle/10347/4341). "Brain Dynamics" Volume 1, Gonzalo I. (Ed), English translation, Madrid 2022 (Open Access in this web page). English translation (2022) of Volume 2 of Brain Dynamics by Justo Gonzalo is freely available at at: https://eprints.ucm.es/id/eprint/72118/ English translation (2015, revised 2022) of ubsequent research by this author is freely available at: https://eprints.ucm.es/id/eprint/30931/This book is the English translation of the published book in Spanish: `Dinámica Cerebral´, by Justo Gonzalo, Volume 1, published by the Consejo Superior de Investigaciones Científicas, Madrid 1945. A facsimile Spanish edition includindg Volume 2 and supplements was published by the Red Temática en Tecnologías de Computación Artificial/Natural (RTNAC) and the University of Santiago de Compostela in 2010, and whose on-line open-access version (http://dspace.usc.es/handle/10347/4341) maintains a significant rate of visits since its publication. Justo Gonzalo (Barcelona 1910 - Madrid 1986), after specialization in Austria and Germany, developed a novel research on the human cerebral cortex, partially exposed in this book. The research described here is surprisingly of current interest, apart from its undoubted historical interest. Some aspects were ahead of discoveries that were made later. Some of the phenomena exposed are still unknown, or have only been observed in the last decades, and the functional dynamic unity of the cortex proposed by the author is closely related to the current trends in the study of the brain. Some singular phenomena are described with extreme detail, such as inverted vision, facilitation, delocalization of colors, reversal of motion, and orientation disorder, among others. From the study of patients with unilateral lesion in an association area of the left parieto-occipital cortex, the author characterized what he called the `central syndrome´ of the cortex as a multisensory disorder in which all functions are affected bilaterally and symmetrically, presenting dynamic phenomena such as disaggregation of a sensory function into partial functions that are united in normal perception. Thus, inverted or tilted vision appears, whose first in-depth study is part of this research. A related phenomenon is partial disappearance of the disorders by intensification of the stimulus, or by means of facilitation, according to which the perception of a stimulus improves by the presence of another stimulus of the same or of a different sensory modality (cross-modal effect), or by a motor stimulus, muscular effort being one of the most efficient and less known means. The greater the brain excitability deficit, the more efficient facilitation is. The first detailed study on multisensory and motor facilitation is part of this research. Multisensoriality is a topic of great interest at present. From the new approach that the author gave to the research, his conception of brain dynamics emerged. The term `brain dynamics´, so widely used today, was introduced here for the first time in relation to sensory organization. This research filled the gap then existing between brain pathology and the physiology of the nervous system since the phenomena described find explanation on a physiological basis governed by the laws of nervous excitability, and provides a dynamic solution to the rigid theory of brain localization by establishing a continuous transition between lower and higher sensory functions, both being based on the same physiological laws. In addition to the patients directly studied by the author, a reference case is also the famous Schneider patient of Goldstein and Gelb studied in 1918-1919, which deserves publications even at present, and which the author interpreted under the central syndrome. In this Volume 1, the first part deals qualitatively with general aspects of the research (findings, new syndrome, dynamic analysis), and a the second part focuses on the quantitative and experimental aspects concerning visual functions. This part covers electrical and light excitability, color vision, visual field, visual forms, color vision, motion perception, motion inversion, visual image orientation, and visual schema. The rich bibliographic documentation on various trends of thought and clinical data adds interest and amenity to the book. This research received international attention from relevant authors shortly after the first publication of the book in Spanish, and more recently found echo in the field of cybernetics and artificial intelligence. A preface introduces some aspects of this research, its author and his subsequent research.Depto. de ÓpticaFac. de Ciencias FísicasFALSEunpu

The hereditary dystrophies of the posterior pole of the eye

Diminished vision as a result of macular degeneration or changes of the posterior pole of the eye constitutes an important ophthalmological problem. Kornzweig (1957) studied more than rooo eyes and found diminished vision as a result of an affection of the posterior pole in 24.1% of patients under So and 3S.6% of patients over So. Ouly cataract was found to be a more frequent cause of diminished vision. However, whereas the therapeutic possibilities are ample in the case of cataract, they are usually very limited in the many macular affections. Yet a too defeatist attitude towards affections of the posterior pole is undesirable. A better understanding and improved knowledge of macular anomalies and degenerations may well lead to a more effective approach. Precisely in familial dystrophies of the posterior pole, more perceptive interpretation of the clinical features and a knowledge of the mode of transmission can make a meaningful contribution to prophyla..'<is by responsible genetic counselling. In thls conte...'t it must be borne in mind that several dystrophies of the posterior pole cause so little loss of function that prophyla.'<is need not at all be considered. Since the clinical course and prognosis of the various macular degenerations are dependent on the type of affection, improved differentiation is of great importance also

Clinical review of retinotopy

Two observations made 29 years apart are the cornerstones of this review on the contributions of Dr Gordon T. Plant to understanding pathology affecting the optic nerve. The first observation laid the anatomical basis in 1990 for the interpretation of optical coherence tomography (OCT) findings in 2009. Retinal OCT offers clinicians detailed in vivo structural imaging of individual retinal layers. This has led to novel observations which were impossible to make using ophthalmoscopy. The technique also helps to re-introduce the anatomically grounded concept of retinotopy to clinical practise. This review employs illustrations of the anatomical basis for retinotopy through detailed translational histological studies and multimodal brain-eye imaging studies. The paths of the prelaminar and postlaminar axons forming the optic nerve and their postsynaptic path from the dorsal lateral geniculate nucleus to the primary visual cortex in humans are described. With the mapped neuroanatomy in mind we use OCT-MRI pairings to discuss the patterns of neurodegeneration in eye and brain that are a consequence of the hard wired retinotopy: anterograde and retrograde axonal degeneration which can, within the visual system, propagate trans-synaptically. The technical advances of OCT and MRI for the first time enable us to trace axonal degeneration through the entire visual system at spectacular resolution. In conclusion, the neuroanatomical insights provided by the combination of OCT and MRI allows us to separate incidental findings from sinister pathology and provides new opportunities to tailor and monitor novel neuroprotective strategies

Visual dysfunction, but not retinal thinning, following anti-NMDA receptor encephalitis

Objective: To assess structural and functional changes in the afferent visual system following anti-NMDA receptor (NMDAR) encephalitis. Methods: In this cross-sectional study including 31 patients after acute NMDAR encephalitis and matched healthy controls, visual function was assessed as high-contrast visual acuity using Early Treatment Diabetic Retinopathy Study charts and low-contrast sensitivity using Functional Acuity Contrast Test. Retinal changes were measured using optical coherence tomography with assessment of peripapillary retinal nerve fiber layer (pRNFL) and macular intraretinal layer thicknesses. Residual clinical impairment was described using the modified Rankin Scale. Results: High-contrast (logMAR 0.02 ± 0.14 vs −0.09 ± 0.14, p < 0.001) and low-contrast (area under the curve 1.89 ± 0.21 vs 2.00 ± 0.26, p = 0.039) visual acuity were reduced in patients in comparison to healthy controls. More severely affected patients performed worse in visual acuity testing than patients with good recovery (logMAR −0.02 ± 0.11 vs 0.08 ± 0.17, p = 0.030). In contrast, patients did not differ from matched healthy controls in pRNFL or in thickness of intraretinal layers, including the ganglion cell complex, the inner nuclear layer, the outer nuclear and plexiform layers, and the photoreceptor layer. Conclusions: After acute NMDAR encephalitis, patients have mild visual dysfunction in comparison to matched healthy controls, while retinal structure appears unaltered. These observations could point to an impairment of anterior or posterior visual pathway NMDAR function that is similar to dysfunction of NMDAR in cerebral cortex and subcortical structures. Alternatively, residual cognitive impairment might reduce visual function