Papers by Carlo Aleci, MD, Ph.D
Neurological Sciences, Sep 25, 2009
Visual aura is the most common feature associated with migraine, though it can occur separately. ... more Visual aura is the most common feature associated with migraine, though it can occur separately. In both cases it often represents a dramatic event, especially for patients who experience it for the first time. Besides, its subjective characteristics may illuminate on the functional architecture of the visual cortex. Repetitive events of migraine and visual aura have been suggested to affect the visual system in the long run, both on the cortical and precortical level. In effect, objective investigation of visual functions in patients support the idea that a selective damage does occur, so that more attention to visual examination seems to be justified. In this paper, subjective and psychophysical aspects of visual aura are examined, lastly highlighting and discussing the interesting correlations found between this condition and normal-tension glaucoma.
Cureus, Sep 2, 2019
was 94.12% and 77.78%, respectively. Sensibility and specificity of the DD section DD were 100% a... more was 94.12% and 77.78%, respectively. Sensibility and specificity of the DD section DD were 100% and 80%, respectively. Conclusion The AAP2 is a promising tool to screen subjects at risk for developmental dyslexia at the beginning of primary school. Like the previous version (also in this modified questionnaire), the main weakness remains the heuristic criterion adopted for the assignment of the scores.
PubMed, Apr 1, 2015
In a previous study dated back to 2001, a small sample of cyclotropic patients were found to be a... more In a previous study dated back to 2001, a small sample of cyclotropic patients were found to be affected by abnormal spatial relationship perception (aspect ratio judgment) with increased discrimination threshold of elliptical targets oriented along the horizontal axis. The angular amount of incyclodeviation correlated significantly with the discrimination threshold along the horizontal axis. Our group made a similar finding some years later in subjects suffering from Menière's syndrome. In both cases, we advanced bulbar torsion to be responsible for the reduced sensibility to spatial relationship along the x-coordinate. Still, a possible explanation and a tentative model accounting for the results at that time had not been provided. This paper aims at making up for the gap, advancing a paradigm that explains the increased discrimination threshold in cyclotropic eyes as a function of the angular discrepancy between the horizontal coordinate on the retinal plane, corresponding to the maculopapillary axis (the "retinal horizon"), and the horizontal coordinate in the visual space (the "spatial horizon"). This angular discrepancy is posited to produce abnormal encoding of the spatial relationship of the target, leading to an unbalanced activation of the two antagonistic cellular pools responsible for the analysis of the aspect ratio at the cortical level. Such a model of the "dual horizon" seems to be able to account for the experimental finding described in the previous paper, providing a theoretical explanation for the defective sense of space in patients suffering from cyclotropia.
The Open Ophthalmology Journal, Nov 25, 2008
Purpose of the study was to compare Rarebit Perimetry (RP) with Standard Automatic Perimetry (SAP... more Purpose of the study was to compare Rarebit Perimetry (RP) with Standard Automatic Perimetry (SAP) in patients with ischemic retrochiasmal lesions. Seventeen patients with homonymous hemianopia underwent SAP and RP. Correlation between the two techniques was evaluated, congruent defects were quantified in the spared hemifield and residual vision areas were investigated in the blind hemifield. A strong correlation was found between SAP and RP. In the spared hemifield, RP detected congruent defects in a higher percentage of cases. Residual detection function has been found at RP in 69,2 % of perimetrically blind visual field quadrants as assessed by SAP. In conclusion, RP appears to be useful to assess visual function in hemianopic patients. As compared to SAP, it seems able to detect small congruent defects in a higher percentage of cases. Finally, a certain residual function seems to be present at RP in the blind regions of the visual field, however, for this finding further demonstrations are required.
Archives of current research international, Aug 31, 2019
Aims: A computational model aimed to estimate the proportion of visual/motor deficits (first-orde... more Aims: A computational model aimed to estimate the proportion of visual/motor deficits (first-order defects) and visual-motor abnormal integration (second-order defect) in dyslexic children is described. Study Design: Single-masked case-control study.
American journal of medical and biological research, Feb 25, 2014
Although in experimental psychology the fixation/saccadic sequence is a main topic of debate, so ... more Although in experimental psychology the fixation/saccadic sequence is a main topic of debate, so far in the clinical ophthalmological field such an argument has raised relatively few interest. Nevertheless, studying the possible alterations of the saccadic rate and of the positioning of fixations when analyzing a visual scene may illuminate on the source of reading difficulty in a variety of patients, like dyslexic children or those affected by hemianopia as well as central visual field impairment. Recently, new light has been shed on the saccadic/fixation dynamics, both in the temporal and spatial domain. In addition, according to recent findings a visuoperceptive distortion could potentially affect the saccades/fixation sequence, making the matter much more complex than expected. The aim of this article is therefore to describe the saccadic/fixation seesaw under the temporal and spatial perspective and to disclose the possible influence of visuoperceptive impairments.
Archives of current research international, Sep 7, 2020
Developmental dyslexia, one of the most common neuro-developmental disorders, is frequently under... more Developmental dyslexia, one of the most common neuro-developmental disorders, is frequently under-diagnosed or diagnosed late. Despite there is consensus on the neurobiological and genetic basis and on the environmental influence, the multi-faceted aspects of dyslexia and the complexity of its phenotypic expression hinder the identification of the risk factors. Indeed, determining risk factors and understanding how they predispose to the reading disability is important for an early diagnosis and a satisfactory rehabilitative outcome. The aim of this paper is therefore to provide an overview on the genetic, biochemical, anatomical and environmental variables involved in the pathogenesis of developmental dyslexia, and on the visual-perceptual aspects that characterize children who struggle to read.
Cortex, Apr 1, 2012
According to wide literature, a global impairment in the temporal and spatial domains as well as ... more According to wide literature, a global impairment in the temporal and spatial domains as well as an increased crowding effect is common of dyslexics. The aim of the study was to evaluate if such subjects suffer from a more general impairment of spatial relationship perception (SRP) and in particular from anomalous spatial relationship anisotropy (SRA) thus accounting both for their global perceptual distortions and abnormal crowding. SRP of 39 young disabled readers and 23 normal subjects were measured by a specifically designed psychophysical technique based on circular and elliptical target recognitions. A general impairment of SRP characterized by increased horizontal/vertical anisotropy was found in the dyslexic sample compared to the controls. In the second part of the experiment, reading efficiency and reading time were measured by MNREAD ª reading cards in standard conditions and after increasing horizontal spatial extension of the sentence by different values. We suppose this modification could well compensate the abnormal anisotropy found in dyslexics. Data obtained in the two groups were compared. A strong correlation between reading efficiency (a parameter we have specifically devised) and horizontal spatial text relationship values were present in the patients (r ¼ .87, p < .01), but not in the controls. The same was found taking into consideration mean reading time (r ¼ À.82, p < .01). We therefore gather that an alteration of SRP, characterized by an increased anisotropy may be involved in developmental dyslexia.
British journal of medicine and medical research, Jan 10, 2014
Aims: To assess sensory ocular dominance of children by means of a novel psychophysical technique... more Aims: To assess sensory ocular dominance of children by means of a novel psychophysical technique (Domitest-S). Study Design: population study. Place and Duration of Study: Department of Ophthalmology, The Gradenigo Hospital, Turin, between June 2012 and June 2013. Methodology: Thirty sequences of stimuli (15 for the left eye and 15 for the right eye) were administered in dichoptic conditions to 152 pupils (mean age: 9 ± .8 years). The task was to detect the target (a checkerboard-like pattern arranged so as to form an “X”) embedded in a series of null stimuli (checkerboard-like patterns randomly arranged). Left and right proportion correct responses were computed and an index of dominance laterality, the Balance Value (BV), expressed as the right minus left proportion correct responses was introduced. A second index based on the total amount of percent correct responses, the Interocular Inhibitory Index (III) was computed to provide a measure of reciprocal binocular suppression. Results: The frequency distribution of sensory dominance was not normal, but skewed on the left (KS=.17, P<.001). The median was .20 (range .00-.80) with 77% of the subjects showing a BV between .00 and .27. A substantial equivalence was found Original Research Article British Journal of Medicine & Medical Research, 4(6): 1371-1382, 2014 1372 between the proportion of right and left dominants (46%). Balance values ranging from – .20 to +.27 accounted for 79% of the variance. The distribution of the reciprocal interocular suppression measured as III was bimodal, showing two peaks, one on the right (lower inter-inhibitory effect) and the other on the left (stronger inter-inhibitory effect). Test-retest reliability was acceptable (correlation between the left and right correct responses at first and second examination: Spearman r= .54, P< .001). The duration of the examination was about 5 minutes. Conclusion: Domitest-S proves to be a fast and reliable technique to assess sensory dominance in children within the clinical setting.
EDP Sciences eBooks, Mar 8, 2021
All rights relative to translation, adaptation and reproduction by any means whatsoever are reser... more All rights relative to translation, adaptation and reproduction by any means whatsoever are reserved, worldwide. In accordance with the terms of paragraphs 2 and 3 of Article 41 of the French Act dated March 11, 1957, "copies or reproductions reserved strictly for private use and not intended for collective use" and, on the other hand, analyses and short quotations for example or illustrative purposes, are allowed. Otherwise, "any representation or reproductionwhether in full or in partwithout the consent of the author or of his successors or assigns, is unlawful" (Article 40, paragraph 1). Any representation or reproduction, by any means whatsoever, will therefore be deemed an infringement of copyright punishable under Articles 425 and following of the French Penal Code.
Research, Jun 5, 2015
In neuro-ophthalmology the clinical management cannot help but start with an accurate anamnestic ... more In neuro-ophthalmology the clinical management cannot help but start with an accurate anamnestic evaluation. In this case signs and symptoms depend not only on the severity of the alleged disease, but also on the degree of impairment that affects the two functional domains the visual system is made of: namely, the visuomotor and the visuosensory domains (VMD and VSD). The Analytic Anamnestic Protocol (AAP) is a set of questions devised to measure the effect clinical features affecting relatives may have on the actual clinical condition of the patient, as well as to mathematically analyze past and actual symptoms reported by the subject. Each answer is assigned a score that expresses the amount of visuomotor (M) and visuosensory (S) impairment. At the end of the protocol the final M-and Sscores are computed as the sum of M and S at each response. This way the expected proportion between visuomotor and visuosensory alteration in the patient can be computed. The questionnaire has been administered to 200 normal subjects, 98 patients suffering from cerebral lesion, 75 dyslexics and 24 patients with Down syndrome. In the pathological groups M-and S-scores were higher compared to the normal sample. In particular Sand M-score in dyslexics revealed a main visuosensorial impairment (median S-score: 9 (IR=13), median M-score: 2 (IR=3). In the other two samples the VMD and VSD involvement turned out to be roughly the same. ROC curves, sensitivity and specificity demonstrated the AAP to have good accuracy in discriminating the pathological cases. In conclusion the Anamnestic Analytic protocol proves to be a valid alternative to the current medical history collection, having the advantage to quantify and characterize predisposing factors towards the disease. In this context the AAP provides the physician with preliminary information that, supplemented by diagnostic instrumental data and by the clinical examination, is expected to increase the diagnostic accuracy.
Ophthalmology research: an international journal, Jul 2, 2020
The damage to the visual field is the main outcome of glaucoma. Basically, there are two differen... more The damage to the visual field is the main outcome of glaucoma. Basically, there are two different approaches to establish the rate of the functional loss in this clinical condition: event-based analysis and trend-based analysis. The event-based analysis, that relies on the occurrence of preestablished events to detect the progression of the visual field damage, cannot quantify the decay rate of sensitivity. In turn, the trend-based analysis, that aims to measure the rate of progression according to linear regression models, requires a long follow-up. Despite considerable effort, there is still no consensus on the optimal procedure, and a gold standard is still missing. This paper provides a quick overview of the topic as a tribute to the researchers engaged in this field.
International Ophthalmology, Sep 19, 2017
Purpose To describe a novel optokinetic visual acuity estimator (Oktotype) and to report the prel... more Purpose To describe a novel optokinetic visual acuity estimator (Oktotype) and to report the preliminary results obtained in poorly and non-collaborative subjects. Methods Eleven series of symbols arranged horizontally and moving from left to right at a constant rate were displayed. In each sequence, the size of the stimuli was reduced logarithmically. By using this paradigm, the objective visual acuity was computed in 26 normal subjects as the minimum size of the symbols able to evoke the optokinetic response. In the preliminary phase, three contrast levels were tested, with white noise added to the first five sequences so as to normalize the overestimate found at the lower-half range of the acuity scale. Subsequently, the correspondence between subjective and objective visual acuity was compared in 10 poorly collaborative subjects, and the agreement between optokinetic and Teller visual acuity was measured in six non-collaborative subjects. Results The best agreement is provided by the minimum contrast level (20%) (R 2 = 0.74). The correspondence between the two techniques is satisfying both in the normal and in the poorly collaborative sample (concordance correlation coefficient: 0.85 and 0.83, respectively). In the non-collaborative group, the concordance correlation coefficient between Teller acuity and OKVA ranged between 0.79 (test) and 0.85 (retest). Test-retest reliability was very good for the Oktotype (K: 0.82), and better than the Teller test (K = 0.71), even if it was lower compared to Snellen acuity (K = 0.95). Conclusion The Oktotype seems promising to predict Snellen visual acuity in normal and poorly collaborative subjects.
The Open Ophthalmology Journal, Aug 31, 2010
Spatial relationship perception (SRP), defined as the function able to detect the difference betw... more Spatial relationship perception (SRP), defined as the function able to detect the difference between the perceived extent of a shape along the x/y cardinal coordinates, has been investigated in 42 eyes of 21 emmetropic subjects by means of a psychophysical test conceived on purpose. Aiming to the highest sensibility and since curvature detection is reckoned as an hyperacuity, elliptical stimuli have been chosen to measure the spatial relationship anisotropy (SRA) in the visual system. Observers turned out to be able to detect curvature differences along the elliptical contour as low as 33.6 sec arc, which in terms of SRP means an aspect ratio (i.e. the ratio between the height and the width of the ellipse) as low as 1.0022-1.0035. By comparing these results with those obtained in previous investigations from other curvature discrimination tasks, it is argued that recognition threshold is conditioned by the amount of space anisotropy of the visual system. Indeed, in about half of the recruited subjects, vertical/horizontal anisotropy is found to a certain extent and such SRA correlates with the recognition threshold (r= 0.69, p<0.01). There is direct evidence of visual spatial distortion and in particular increased anisotropy in neuro-ophtalmological diseases such as hemianopia and around scotomatous regions in the visual field. Thence, apart from theoretical considerations in physiological field, results collected in this study may be regarded as normative data for future clinical investigations.
Annals of Eye Science, Dec 1, 2022
Perception is the ability to see, hear, or become aware of external stimuli through the senses. V... more Perception is the ability to see, hear, or become aware of external stimuli through the senses. Visual stimuli are electromagnetic waves that interact with the eye and elicit a sensation. Sensations, indeed, imply the detection, resolution, and recognition of objects and images, and their accuracy depends on the integrity of the visual system. In clinical practice, evaluating the integrity of the visual system relies greatly on the assessment of visual acuity, that is to say on the capacity to identify a signal. Visual acuity, indeed, is of utmost importance for diagnosing and monitoring ophthalmological diseases. Visual acuity is a function that detects the presence of a stimulation (a signal) and resolves its detail(s). This is the case of a symbol like "E": the stimulus is detected, then it is resolved as three horizontal bars and a vertical bar. In fact, within the clinical setting visual acuity is usually measured with alphanumeric symbols and is a three-step process that involves not only detection and resolution, but, due to the semantic content of letters and numbers, their recognition. Along with subjective (psychophysical) procedures, objective methods that do not require the active participation of the observer have been proposed to estimate visual acuity in non-collaborating subjects, malingerers, or toddlers. This paper aims to explain the psychophysical rationale underlying the measurement of visual acuity and revise the most common procedures used for its assessment.
Ophthalmology research: an international journal, Jan 10, 2014
Aims: There is evidence that the deprivation of a sensory system at early developmental stage may... more Aims: There is evidence that the deprivation of a sensory system at early developmental stage may lead to a functional change of the remaining one(s). Even if this process has been widely studied, results are still controversial. In particular, the auditory system might affect the oculomotor control, since saccades or fast eye movements (FEMs) and slow eye movements (SEMs) are modulated by the cochleo-vestibular input. It follows that hearing impairment would affect the SEM and saccadic pattern. Therefore, in this study FEMs and SEMs have been evaluated in congenital deaf subjects in order to state whether early auditory deprivation has influence on the oculomotor function. Study Design: Case-control study.
Ophthalmic and Physiological Optics, Jun 19, 2018
Ophthalmology research: an international journal, Jan 10, 2017
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Papers by Carlo Aleci, MD, Ph.D