Assessment Of Visual Function Research Articles

Study protocol for a randomized controlled trial of the NEIVATECH virtual reality system to improve visual function in children with anisometropic amblyopia

BackgroundInterest in developing alternative methods for the treatment of amblyopia has long been a topic of interest among clinicians and researchers, as prescribed occlusion and penalization therapies do not always provide an effective response and are associated with a high risk of recurrence and non-compliance. Here, we present the protocol of a small-scale RCT to evaluate the safety and clinical efficacy of a novel VR-based system designed to provide binocular vision training to children with anisometropic amblyopia.MethodsWe aim to recruit a total of 60 children with anisometropic amblyopia aged 5-17 years with no previous treatment for amblyopia other than refractive correction from the pediatric ophthalmology units of the University Clinical Hospital of Valladolid and the Vithas Medimar International Hospital of Alicante. Children who meet the eligibility criteria and consent to participate will be randomly assigned to a three-month intervention group of 18 half-hour in-office therapy sessions with the NEIVATECH system (group A) or to a parallel group receiving 2 hours of conventional patching per day at home for the same period of time (group B). Assessments of visual function will be carried out before the intervention and at 1, 2 and 3 months, with changes in distance BCVA being the primary outcome measure to be considered. Patient safety, compliance, satisfaction and acceptance to treatment will also be assessed after therapy as other valuable outcome measures. In addition, a rsfMRI scan will be performed on a subgroup of 5 patients from each group at the pre-intervention visit and at the post-intervention visit to test the effects of both therapies on neural plasticity in the visual cortex.DiscussionThe NEIVATECH system has been conceived as a serious game designed to provide binocular vision training to anisometropic amblyopic children by complementing the concepts of perceptual learning, dichoptic training and gamification in an immersive VR environment. We hope that this novel approach may lead to greater improvements in vision performance than those provided so far by conventional patching in anisometropic amblyopic children.Trial registrationThis protocol was registered with ClinicalTrials.gov (NCT04819386) on 29 March 2021.

Development of Immersive Virtual Reality Environment for Assessment of Functional Vision in people with Low Vision: A Pilot Study.

Virtual Reality technology helps in creating virtual environments for evaluation of visual performance of low vision individuals with holistic experience. The purpose of this study was to develop a virtual reality (VR) platform for the objective assessment of functional vision in patients with low vision in two categories, central and peripheral vision loss . Focus group discussions (FGD) were organized to understand the difficulties faced on a day to day basis by patients with low vision. Based on the results of the focus group discussions, a virtual bank scenario incorporating specific visual tasks was developed. A pilot study was conducted which involved people with normal vision; low vision Patients secondary to central field loss (CFL) and peripheral field loss (PFL). Each subject completed all the tasks in the objective assessment; the data obtained from the assessment were further analyzed to understand the pattern. Comparing the three groups, there was a significant difference in distance (central field loss was lowest) and near visual angle, and three visual search tasks (peripheral field loss was lowest). In assessing the time taken, peripheral field loss group was again found to take the most time to complete tasks. Based on a newly developed virtual reality platform, assessment of functional vision of specially abled persons could be tested and was inferior to that of normal sighted persons. in a close to realistic environment. Multiple visual tasks were performed in the virtual environment and the visual performance was compared among all three groups of participants. Participants were matched for age and gender. Irrespective of the nature of tasks, visual performance of the normal group seemed significantly better than people with CFL and PFL.

Rapid Quantification of the Binocular Visual Field for Clinical Trials: Performance of a Modified Esterman Supra-Threshold Test Implemented with the Open Perimetry Interface.

PurposeWe aimed to assess the performance of the modified-Esterman test (mET) as a rapid suprathreshold binocular quantification tool for the assessment of peripheral visual fields. The mET consists of an even spread of test points across the visual field.Materials and MethodsThe mET was implemented on the Octopus 0900 perimeter using the Open Perimetry Interface (OPI) and consisted of 160 points. Patients with choroideremia, a rod-cone dystrophy, Stargardt disease, a cone-rod dystrophy, and healthy volunteers underwent both the mET and the standard Esterman tests twice. Disease severity (mild/moderate/severe) was graded on both tests independently. Voronoi tessellation was utilised to compare the tests.ResultsThe Voronoi visualisation was able to demonstrate that the mET was able to provide more information about the disease state at all stages of diseases. This was confirmed by the agreement statistic, which showed that the mET detected 27% more points of visual field loss compared to the Esterman test, being most useful in patients with rod-cone dystrophies.ConclusionThe mET provides a speedy quantitative measure of the peripheral visual field loss, which can be used in clinical trials to monitor longitudinal assessment of peripheral visual function. The mET provides a more even coverage across the visual field compared to the Esterman test points, making it more suitable for this purpose. This is a key part of safety monitoring in retinal clinical trials. The mET can easily be implemented on commercially available perimeters that allow Open Perimetry.

Intratendinous Injection of Autologous Conditioned Serum for Treatment of Lateral Epicondylitis of the Elbow: A Pilot Study.

Autologous conditioned serum (ACS) has been effectively used in treatment of osteoarthritis. However, less is known about its efficacy in tendon disorders. In this pilot study, we aimed to evaluate the short- and long-term effects of intratendinous injection of ACS in lateral epicondylitis (LE) of the elbow. This prospective cohort included 42 patients with LE of the elbow who received 4 intratendinous injections of Orthokine® (Orthogen Lab Services GmbH, Düsseldorf, Germany) under local anesthesia over 2 weeks in an outpatient setting. The clinical and functional outcomes of injections were evaluated at 3 months and 1 year after the procedure. Pain was assessed using a visual analog scale (VAS) and functional assessment was made using the Mayo Elbow Performance Score (MEPS) and Oxford Elbow Score (OES). The pre-injection VAS score (7.07±1.19) improved significantly after the procedure at both 3 months (3.55±0.56, P<0.001) and 1 year (1.73±0.82, P<0.001). Similarly, the mean MEPSs were significantly different between baseline and 3 months (56.42±7.51 vs. 79.76±3.81, P<0.001) and between baseline and 1 year (56.42±7.51 vs. 94.28±4.06, P<0.001). The baseline OESs (84.17±6.07) also improved with intratendinous injection of ACS at 3 months (41.96±9.23, P<0.001) and 1 year (7.43±4.31, P<0.001). Only six patients (14.2%) had mild ecchymosis and swelling around the injection site which resolved spontaneously. ACS is a promising option for treatment of LE of the elbow, given its early onset of pain-relieving action and longlasting functional effects. These findings await confirmation by large-scale and prospective trials.

Impact of visual impairment on balance and visual processing functions in students with special educational needs.

IntroductionVision is critical for children’s development. However, prevalence of visual impairment (VI) is high in students with special educational needs (SEN). Other than VI, SEN students are prone to having functional deficits. Whether visual problems relate to these functional deficits is unclear. This study aimed to assess the impact of vision on visual processing functions and balance in SEN students through a community service.MethodsVisual acuity (VA) and contrast sensitivity were measured in a total of 104 (aged 14.3±4.3) SEN students as the visual outcomes, followed by retinoscopy. Visual processing function assessment included facial expression recognition by card matching examiner’s facial expression matching, and visual orientation recognition. Dynamic balance, by Timed Up and Go test, and static standing balance (postural sway in double-legged standing with feet-together and tandem-stance for open-eye and closed-eye conditions) were assessed. Static balance was presented in terms of the maximal medial-lateral and antero-posterior sways.ResultsOf the 104 students, 62 (59.6%) were classified as visually impaired according to WHO classification of visual impairment based on presenting distance acuity. Ocular problems (e.g. optic nerve anomaly, uncorrected/ under-corrected refractive errors) and neurological anomalies were the major causes of vision loss. VA was positively associated with visual processing functions (all p ≤ 0.01), as SEN students with better vision tended to perform better in visual orientation and facial expression recognition tasks, as well as dynamic balance function (p = 0.04). For the static balance, postural sway and VA showed a positive relationship under open-eye and tandem stance conditions. However, the relationship between postural sway and VA became negative under closed-eye and tandem stance conditions.ConclusionThis study found a high prevalence of SEN students with visual impairment, in which many of them were undetected. Optometric examination is important to improve their visual function to minimize the effect of vision on functional performance. Vision is critical in visual processing as well as playing an important role in maintaining balance in SEN students.

An integrated early intervention approach for children with cerebral visual impairment - A case report

A 2-year-old child with cerebral visual impairment (CVI) was brought by the mother to the pediatric ophthalmology clinic. She underwent a detailed functional vision and developmental assessment that revealed impairments in visual developmental skills, sensory, motor, and social skills. She was admitted into an integrated, parent-centered, structured early intervention program specifically designed for her for 3-months after which there were improvements noticed in visual developmental skills such as visual fixation, attention, and tracking; sensory skills such as tactile, olfactory, and gustatory; motor skills, including neck control and fine motor grasping; and age-appropriate social and communication skills. Through this case report, we aim to bring out the benefits of an evidence-based systematic early intervention approach in a child with CVI.

Analysis of the Reliability and Repeatability of Distance Visual Acuity Measurement with EyeSpy 20/20.

BackgroundVisual acuity is a critical component of visual function assessment for all ages. Standardized vision testing protocols may help prevent testing inconsistencies resulting from variations in test administration and interpretation of different examiners. However, most vision assessments outside of research settings, including in doctor’s offices, rarely employ standardized protocols. Validated protocols such as the Early Treatment for Diabetic Retinopathy Study (ETDRS) are frequently employed by vision researchers to ensure accurate and repeatable visual acuity measurements.MethodsThis study evaluates a desktop-based standardized vision testing algorithm (EyeSpy 20/20) specifically designed for use on mobile electronic platforms. Subjects were tested on a desktop version of the EyeSpy software for both the accuracy and duration of measurement of visual acuity and compared to a e-ETDRS chart in a randomized sequence. Children were recruited for this study and tested between two different visual acuity measurement systems. Bland–Altman analysis and correlation tests were done.ResultsHundred and ten children were recruited for the study. The EyeSpy 20/20 visual acuity testing algorithm as tested with the desktop version was non-inferior to the gold standard e-ETDRS testing algorithm on a desktop platform, but statistically faster to implement when administered on the same electronic testing platform.ConclusionEyeSpy 20/20 is a promising tool for vision screening and visual acuity evaluation in children.

Visual impairment in children with multiple disabilities in schools for children with special needs in South India.

Purpose:To understand/assess ocular and functional vision impairment in children with multiple disabilities with a functional vision assessment battery in addition to standard ophthalmic examinations in an outreach setting.Methods:Seven schools for children with special needs, 243 children in total, were screened for ocular disorders and functional vision impairment through school camps.Results:Among them, 37% had refractive errors needing spectacle correction. With standard ocular testing methods, the visual impairment was around 32%, but when functional vision was assessed, the functional vision impairment amounted to 70% in these children. The presence of functional vision impairment was found to be independent of the associated disability. Assessment of visual capacities such as visual closure, saccade pursuits, optic ataxia, and developmental milestones early on can help in suspecting the presence of CVIConclusion:Children with multiple disabilities are more at risk of functional vision impairment, which significantly impairs their ability to function in daily life. A complete functional vision assessment becomes essential to plan early intervention for these children. The significant proportion of vision impairment and functional vision loss in our study indicates the need for coordinated structured programs to address vision-related problems in children with multiple disabilities.

Association of sensory impairment with healthcare use and costs among middle-aged and older adults in China

ObjectivesThis study aimed to explore the association of visual, hearing, or dual sensory impairment with healthcare use and costs. Study designThis is a cohort study. MethodsThese research data were from the China Health and Retirement Longitudinal Study spanning 2011–2018 and included 8982 community-dwelling middle-aged and older adults (aged ≥45 years at baseline). Sensory impairment was measured according to self-reported assessment of visual and hearing functions, and healthcare use and costs were ascertained via self-report. The associations of sensory impairment with healthcare use and costs were estimated using the mixed-effects regression models. ResultsOf the 8982 respondents, 4346 (48.39%) were females and their mean (standard deviation) age at baseline was 57.03 (8.26) years. Individuals with hearing impairment (HI) only, visual impairment (VI) only, and dual sensory impairment (DSI) were all at significantly higher risks of healthcare use and catastrophic health expenditure than those without sensory impairment (all P < 0.05), except that VI only non-significantly prolonged inpatient days. Compared with no impairment, DSI was associated with increases in outpatient (β = 50.67, 95% confidence interval [CI] = 17.47–83.86) and inpatient out-of-pocket costs (β = 40.35, 95% CI = 5.94–74.76), while VI only or HI only did not show significant effects. Further stratification analyses indicated that the associations between sensory impairment and outpatient use were more pronounced among males than among females but that age group did not moderate the associations with any healthcare outcomes. ConclusionsHI and VI were independently and together associated with higher risks of healthcare use and catastrophic health expenditure. Dual sensory impairment was the only category consistently associated with increased outpatient and inpatient costs.

Resting-State fMRI in Chronic Patients with Disorders of Consciousness: The Role of Lower-Order Networks for Clinical Assessment.

Resting-state fMRI (rs-fMRI) is a widely used technique to investigate the residual brain functions of patients with Disorders of Consciousness (DoC). Nonetheless, it is unclear how the networks that are more associated with primary functions, such as the sensory–motor, medial/lateral visual and auditory networks, contribute to clinical assessment. In this study, we examined the rs-fMRI lower-order networks alongside their structural MRI data to clarify the corresponding association with clinical assessment. We studied 109 chronic patients with DoC and emerged from DoC with structural MRI and rs-fMRI: 65 in vegetative state/unresponsive wakefulness state (VS/UWS), 34 in minimally conscious state (MCS) and 10 with severe disability. rs-fMRI data were analyzed with independent component analyses and seed-based analyses, in relation to structural MRI and clinical data. The results showed that VS/UWS had fewer networks than MCS patients and the rs-fMRI activity in each network was decreased. Visual networks were correlated to the clinical status, and in cases where no clinical response occurred, rs-fMRI indicated distinctive networks conveying information in a similar way to other techniques. The information provided by single networks was limited, whereas the four networks together yielded better classification results, particularly when the model included rs-fMRI and structural MRI data (AUC = 0.80). Both quantitative and qualitative rs-fMRI analyses yielded converging results; vascular etiology might confound the results, and disease duration generally reduced the number of networks observed. The lower-order rs-fMRI networks could be used clinically to support and corroborate visual function assessments in DoC.

Age-Related Effects on the Spectrum of Cerebral Visual Impairment in Children With Cerebral Palsy.

BackgroundCerebral Visual Impairment (CVI) is a very common finding in children affected by Cerebral Palsy (CP). In this paper we studied the characteristics of CVI of a large group of children with CP and CVI, describing their neurovisual profiles according to three different age subgroups (subgroup 1: infants 6 months–2 years; subgroup 2: pre-school age 3–5 years; subgroup 3: school age ≥ 6 years).MethodsWe enrolled 180 subjects (104 males, mean age 66 ± 42.6 months; range 6–192 months) with CP and CVI for the study. We carried out a demographic and clinical data collection, neurological examination, developmental or cognitive assessment, and a video-recorded visual function assessment including an evaluation of ophthalmological characteristics, oculomotor functions, and basic visual functions. In school-aged children, we also performed an evaluation of their cognitive-visual profiles.ResultsThere were signs of CVI in all the three subgroups. Subgroup 1 (62 children) and subgroup 2 (50 children) were different for fixation (p = 0.02), visual acuity (p = 0.03) and contrast sensitivity (p < 0.01), being more frequently impaired in younger children. Comparing subgroup 2 with subgroup 3 (68 children), the older children presented more frequently myopia (p = 0.02) while the younger ones esotropia (p = 0.02) and alteration in smooth pursuit (p = 0.03) and saccades (p < 0.01). Furthermore, fixation, smooth pursuit, visual acuity, contrast sensitivity and visual filed (p < 0.01) were more frequently impaired in younger children (subgroup 1) compared to the older ones. Multiple correspondence analysis (MCA) confirmed the different neurovisual profiles according to age: younger children with CP showed more signs of CVI compared to the older ones. 34 out of 68 children belonging to subgroup 3 underwent the cognitive visual evaluation; an impairment of cognitive visual skills was detected in 21 subjects.ConclusionYounger children with CP showed more signs of CVI compared to the older ones, likely for the physiological maturation of visual system and mechanisms of neuroplasticity. In this direction, we suggest an early neurovisual evaluation to detect any weak visual functions.

Assessing the impact of monocular deprivation on visual evoked potentials, behavior, and visual plasticity in juvenile mice.

BackgroundThe physiological mechanisms which underlie amblyopia are predicted using animal models which assess the impact of amblyogenic factors on visual function. This study used monocular-deprived mice as an amblyopic model to assess visual function by flash visual evoked potentials (fVEP), behavioral assessment, and visual plasticity.MethodsA total of 294 C57BL/6J mice (both genders) were used in this study. The mice were divided into the normal control (NC) group and monocular deprivation (MD) group. After mice were anesthetized with pentobarbital, fVEP was recorded. Long-term potentiation (LTP) was recorded from primary visual cortex slices. Behavioral assessment of visual function was performed using a visual water trapezoidal-shaped pool with a release chute, a hidden platform, and a middle divider.ResultsAll fVEP results showed that N1 waves and P2 waves were repeatable and N1–P2 amplitude was the most stable indicator. The amplitude of N1–P2 of MD eyes was significantly lower than that of non-deprived eyes or NC eyes. LTP failed to be induced in the visual cortex V1 area corresponding to deprived eyes in the MD group but could be induced successfully in the visual cortex V1 area corresponding to non-deprived eyes in the MD group. Behavioral vision testing also showed a longer time to reach the platform in MD mice compared to NC mice. The correlation coefficient suggested that LTP is the better indicator for visual impairment.ConclusionsThe fVEP can be utilized as an index of amblyopic changes in mice, which correlates well with behavioral results.

Multiprofessional Neurorehabilitation After COVID-19 Infection Should Include Assessment of Visual Function

ObjectiveTo report vision-related symptoms and neuro-visual clinical signs in patients approximately 4 months after discharge from hospitalization after COVID-19 infection. To report on coexisting functional and activity limitations. DesignThe study is part of an ambidirectional population-based cohort study. SettingAn outpatient setting in a hospital environment. ParticipantsPatients from a population-based cohort study including all patients with laboratory-confirmed COVID-19 admitted to hospital during a 3-month period in a health care region in Sweden. Among patients who, based on a standardized telephone interview, were identified as having persisting rehabilitation needs 4 months after discharge (n=185), several (n=57) reported vision-related symptoms. All 57 patients were invited to a neuro-visual examination. Six patients declined, 6 were unavailable, and 3 did not fulfil the inclusion criteria. Thus, 42 patients were included in the analysis (N=42). InterventionsNot applicable. Main Outcome MeasuresVision-related symptoms, neuro-visual function, and coexisting impairments affecting activities of daily life and participation. ResultsA total of 31% of patients with rehabilitation needs after COVID-19 reported vision-related symptoms. Reading-related issues (73.8%), blurry vision (69.0%), and light sensitivity (66.7%) were the most common symptoms. Patients with reading-related issues showed a higher level of eye strain (P<.001). Neuro-visual deficits were found in 83.3% of the patients, mainly concerning eye teaming (23.1%-66.7%) and eye movement (28.6%-30.8%) functions. Patients with vision-related symptoms reported fatigue and 18 other coexisting symptoms to a greater extent (P≤.0001 to .049). ConclusionsNeuro-visual symptoms and signs should be considered when assessing rehabilitation needs after COVID-19. The association between vision-related issues and coexisting symptoms with an effect on body function and activity and/or participation underlines the need for multiprofessional rehabilitation assessment and intervention.

Erratum: Behavioral Assessment of Visual Function via Optomotor Response and Cognitive Function via Y-Maze in Diabetic Rats.

An erratum was issued for:Behavioral Assessment of Visual Function via Optomotor Response and Cognitive Function via Y-Maze in Diabetic Rats. The author list was updated. The author list was updated from: Kaavya Gudapati*1,2, Anayesha Singh*1,3, Danielle Clarkson-Townsend1,4, Andrew J. Feola1,2, Rachael S. Allen1,2 1Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 2Department of Biomedical Engineering, Georgia Institute of Technology, 3Department of Neuroscience, Emory University, 4Gangarosa Department of Environmental Health, Emory University * These authors contributed equally to: Kaavya Gudapati*1,2, Anayesha Singh*1,3, Danielle Clarkson-Townsend1,4, Stephen Q. Phillips1, Amber Douglass1, Andrew J. Feola1,2, Rachael S. Allen1,2 1Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Medical Center, 2Department of Biomedical Engineering, Georgia Institute of Technology, 3Department of Neuroscience, Emory University, 4Gangarosa Department of Environmental Health, Emory University * These authors contributed equally.

Functional outcomes of penetrating eye injuries in children

To assess visual acuity (VA) in the outcome of a penetrating wound of the eyeball in children. The study retrospectively analyzed VA in the outcome of type B open trauma of scleral (12.1%), corneal (59.1%), and scleral-corneal (28.8%) localization in 132 children (132 eyes) older than 4 years (mean age 8.3 years), who were admitted to the hospital on the first day after injury. The exclusion criteria from the main selection were: the presence of an intraocular foreign body, the age of patient higher than 4 years old, and the time of admission more than 24 hours post the moment of injury. Visual acuity was checked at the time of discharge from the hospital (average stay was 19.02 days) and amounted to 0-light projection in 50 (37.9%) children; 0.01-0.1 in 43 (32.6%); 0.2-0.3 in 29 (22.0%); above 0.4 in 10 (7.6%). High rate of vascular reactions to trauma was noted on admission on the first day - intraocular hemorrhage (28.8%), hyphema (10.6%), endophthalmitis (5.3%) as a result of a penetrating injury to the eyeball - as well as their negative effect on vision at discharge. Upon discharge from the hospital, in 92.4% of children the visual acuity in the outcome was 0.3 and below. Adverse visual outcomes significantly correlated with the depth of the injury (correlation coefficient 0.5931) and vascular reactions to trauma (correlation coefficient 0.503333).

Electrophysiological and psychophysical studies in assessment of visual functions in patients with hereditary optic neuropathy

To study the capabilities of electrophysiological and psychophysical examination methods for assessment of the functional state of ganglion cells, retina and optic nerve in patients with hereditary optic neuropathy (HON). The study included 60 patients (118 eyes) with a genetically confirmed diagnosis of HON. All study patients underwent visual field test (VFT), spectral optical coherence tomography (OCT), flash and pattern visual evoked potentials (VEP) (Flash-VEP, FVEP; Pattern-VEP, PVEP), photopic electroretinography with photonegative response (PhNR) registration and the color vision test. In 24 patients (46 eyes), these parameters were assessed before the start of treatment and one year later. The treatment involved the mitochondria-targeted antioxidant SkQ1 - plastoquinonyl-decyl-triphenylphosphonium bromide (PDTP) in the form of eye drops. The main PVEP components for 1.0° and 0.3° were registered in 20% and in 14% of patient eyes with HON and high visual functions, respectively. After one year of PDTP use, a significant decrease in P100 peak latency was found only in the group with disease duration of ≤1.5 years as of the time of treatment start (p<0.05). Significant differences were observed in the PhNR amplitude (p<0.004) between patients of the main and the control groups, as well as in the PhNR amplitude between patients with visual acuity of ≤0.1 and ≥0.13 (p<0.01). Patients with high visual functions were found to have a correlation between the PhNR amplitude, GCC thickness and the global loss index (GLV). Along with VFT, OCT and color vision tests, electrophysiological studies are one of the main methods of examining patients with HON. After one year of PDTP use, there was a significant decrease in the FVEP P2 peak latency in the group with a disease duration of ≤1.5 years as of the time of treatment start. The PhNR amplitude in patients with high visual functions was found to correlate with structural changes in the ganglion cell layer and the retinal nerve fiber layer.

Construct validity of a clinically correlated knee osteoarthritis ultrasonographic scale: a cross-sectional observational study

ObjectivesTo assess the validity of a novel ultrasonographic scale for knee osteoarthritis (KOA) and its relation with the degree of pain and clinical features.DesignA cross-sectional observational study including 245 patients...

Macular Morpho-Functional and Visual Pathways Functional Assessment in Patients with Spinocerebellar Type 1 Ataxia with or without Neurological Signs.

Spinocerebellar ataxia type 1 (SCA-ATXN1) is an autosomal dominant, neurodegenerative disease, caused by CAG repeat expansion in the ataxin-1 gene (ATXN1). In isolated reports of patients with neurological signs [symptomatic patients (SP)], macular abnormalities have been described. However, no reports exist about macular anomalies in SCA1 subjects carrying the ATXN1 mutation without neurological signs [not symptomatic carriers (NSC)]. Therefore, the main aim of our work was to evaluate whether the macular functional and morphological abnormalities could be detectable in SP, genetically confirmed and with neurological signs, as well as in SCA-ATXN1-NSC, harboring pathogenic CAG expansion in ATXN1. In addition, we investigated whether the macular involvement could be associated or not to an impairment of RGCs and of their fibers and of the neural conduction along the visual pathways. Herein, nine SCA-ATXN1 subjects (6 SP and 3 NSC) underwent the following examinations: visual acuity and chromatic test assessments, fundus oculi (FO) examination, macular and peripapillary retinal nerve fiber layer thickness (RNFL-T) analysis by Spectral domain-Optical Coherence Tomography (Sd-OCT) acquisition, multifocal electroretinogram (mfERG), pattern reversal electroretinogram (PERG) and visual evoked potentials (VEP) recordings. In four eyes of two SP, visual acuity reduction and chromatic abnormalities were observed; in three of them FO changes associated with macular thinning and outer retinal defects were also detected. In three NSC eyes, slight FO abnormalities were associated with qualitative macular morphological changes. By contrast, abnormal mfERG responses (exclusively from foveal and parafoveal areas) were detected in all SP and NSC (18 eyes). No abnormalities of PERG values, RNFL-T, and VEP responses were found, but in one SP, presenting abnormal papillo-macular bundle neural conduction. Results from our SCA-ATXN1 cohort suggest that a macular dysfunction, detectable by mfERG recordings, may occur in the overt disorder, and unexpectedly in the stage of the disease in which there is still an absence of neurological signs. In NSC, an exclusive dysfunction of preganglionic macular elements can be observed, and this is associated with both normal RGCs function and neural conduction along the visual pathways.

Assessment of retinal oxygen metabolism, visual function, thickness and degeneration markers after variable ischemia/reperfusion in rats

After total retinal ischemia induced experimentally by ophthalmic vessel occlusion followed by reperfusion, studies have reported alterations in retinal oxygen metabolism (MO2), delivery (DO2), and extraction fraction (OEF), as well as visual dysfunction and cell loss. In the current study, under variable durations of ischemia/reperfusion, changes in these oxygen metrics, visual function, retinal thickness, and degeneration markers (gliosis and apoptosis) were assessed and related. Additionally, the prognostic value of MO2 for predicting visual function and retinal thickness outcomes was reported. Sixty-one rats were divided into 5 groups of ischemia duration (0 [sham], 60, 90, 120, or 180 min) and 2 reperfusion durations (1 h, 7 days). Phosphorescence lifetime and blood flow imaging, electroretinography, and optical coherence tomography were performed. MO2 reduction was related to visual dysfunction, retinal thinning, increased gliosis and apoptosis after 7-days reperfusion. Impairment in MO2 after 1-h reperfusion predicted visual function and retinal thickness outcomes after 7-days reperfusion. Since MO2 can be measured in humans, findings from analogous studies may find value in the clinical setting.

Early Screening of Visual Processing Dysfunctions in Children Born Very or Extremely Preterm.

Introduction: Children with early brain damage or dysfunction are at risk of developing cerebral visual impairment (CVI), including visual processing dysfunctions (VPD), which currently remain largely undetected until school age. Our aim was to systematically screen for possible VPD in children born very or extremely preterm from 1 to 2 years corrected age (CA) and to evaluate the effectiveness of early referral.Method: We included N = 48 children born < 30 weeks from 1 year CA. They underwent a two-step VPD screening based on (1) neurological signs indicative of visual brain damage evaluated by neonatologists and/or pediatric neurologist and (2) a functional assessment of visual orienting functions (VOF) with an eye tracking-based test. If at least one of these assessments was abnormal for their age, the children were classified as a risk of VPD and referred to undergo conventional visual diagnostics: ophthalmic exam and visual function assessment (VFA). At 2 years CA, VOF screening was repeated and neurodevelopment was assessed.Results: 18 children (38%) were classified as at risk of VPD at 1 year CA. 7 children had abnormal neurological signs, 5 children had abnormal VOF, and 6 children had both. Subsequent ophthalmic exams (N = 14) showed severe hypermetropia in 21% and strabismus in 14%. VFA (N = 10) showed abnormal visual function and behavior in only 1 child. At 2 years CA, the total group showed an increase in abnormal VOF. Whereas the children at risk showed some normalization, the group without VPD risk at 1 year CA showed deterioration of VOF. Neurodevelopmental outcome did not clearly differ between risk groups.Conclusion: Our findings show a substantial risk of VPD during visual screening (in 38%) at 1 year CA, but relatively few deficits on subsequent conventional ophthalmic exams and VFA. The data suggest that most conventional visual diagnostic methods at this young age are not related to the established VPD risks. VOF assessment should be used complimentary to these methods. The fact that at 2 years CA the number of children with a VPD risk based on abnormal VOF increased argues for more extensive and continuous screening in risk groups, at least until school age.