Ocular Dominance Research Articles

Electrophysiological response of myopic young adults with a novel ophthalmic lens for the control of myopia progression

Aims/Purpose: To evaluate the changes in the electrophysiological response of the retina induced by a novel perifocal ophthalmic lens designed for myopia control.Methods: This experimental cross‐sectional study, evaluated eleven myopic participants (24.9 ± 4.5 years) with refractive errors lower than 6.00 D (spherical equivalent of −2.40 ± 1.32 D in the right eye and − 2.24 ± 1.56 D in the left eye). Refraction, best‐corrected visual acuity, and axial length were obtained at baseline. The global flash multifocal electroretinogram (gf‐mfERG) was assessed for the sensorial dominant eye with the RETI‐port/scan21 (Roland Consult, Wiesbaden, Germany). The gf‐mfERG recordings were performed with a stimulus array pattern of 61‐scaled hexagons displayed on a 19‐inch RGB monitor at a 33 cm distance (optically corrected). The retina was divided into three groups ‐ the fovea (that included concentric ring 1), the parafovea (rings 2 and 3) and the peripheral retina (rings 4 and 5). The peak‐time (in milliseconds, ms), the amplitude (in nano‐volts, nV) and the mean response density (nV/deg2) of the direct and implicit components (DC and IC, respectively) were analysed and compared between control (monofocal contact lenses) and test conditions (perifocal lenses). These lenses have an add power of +2.50 D on the temporal side, and + 2.00 D on the nasal side, intended to change the peripheral refraction.Results: No differences were found in the DC and IC peak time between the control and test measurements, for the fovea, parafovea and peripheral retina. The mean response density of the DC was higher with the perifocal lens for the perifovea (p‐value = 0.033) and for the peripheral retina (p‐value = 0.026). For the IC, the mean response density was also higher with the perifocal lens, only for the parafovea (p‐value = 0.003).Conclusions: Perifocal lenses for myopia control upregulate the parafoveal and peripheral retinal electrical activity.

The impact of eye dominance on fixation stability in school-aged children

The impact of eye dominance on fixation stability in school-aged children

Optimizing the algorithm for assessing the efficacy of treatment for amblyopia in astigmats through the investigation of the features of meridional acuity characteristics as vector quantities

Background: Refractive asymmetry associated with astigmatism may cause a special form of amblyopia, meridional amblyopia (MA). MA manifests itself as alterations in selective mechanisms of visual stimulus processing during recognition of contours of a certain orientation. Current routine examination of amblyopes does not include meridional acuity assessment and thus does not allow determining whether MA is present or not, as well as performing a more detailed evaluation of the efficacy of treatment for amblyopia in astigmats. Purpose: To optimize the algorithm for assessing the efficacy of stand-alone and complex methods of treatment for amblyopia in astigmats through the determination of the features of changes in visual acuities in orthogonal retinal meridians as vector quantities. Material and Methods: Twenty-four hyperopic astigmats with amblyopia (48 eyes) aged 5 to 12 years were involved in the study. Patients were treated by accommodative facility training only and, in 3 months, by complex therapy (accommodative facility training plus the use of device-based methods). Treatment course duration was 10 days. The results were assessed by changes in best-corrected visual acuity (Sivtsev Chart) and meridional separable visual acuity (MSVA) determined with the software which generates Landolt ring optotypes. Results: The study sample was found to be heterogeneous regarding the features of asymmetries in MSVA. Separable visual acuity in the horizontal meridian was equal in magnitude to that in the vertical meridian in 16.65% of patients. Asymmetries in separable visual acuity that may be considered MA were found in dominant and non-dominant (fellow) eyes in 83.35% of astigmats with amblyopia. Two different clusters were determined in the group with asymmetries in MSVA. Separable visual acuity in the horizontal meridian was higher than that in the vertical meridian in 35.45% of eyes in cluster 1, and lower than that in the vertical meridian in 47.85% of eyes in cluster 2. After treatment, mean separable visual acuity value in the vertical meridian was practically similar to that in the horizontal meridian in both groups for the dominant and fellow eyes, which allowed concluding that both methods were equally effective in treating the disease. However, the number of eyes with the same MSVA in orthogonal meridians increased by 10.41% after MA treatment with accommodative facility training only versus 18.75% after complex treatment. Conclusion: Assessing the features of changes in visual acuities in orthogonal retinal meridians as vector quantities enables obtaining principally new information on the performance of sensory functions in patients with amblyopia and assessing more reliably the efficacy of stand-alone and complex pleoptic methods as methods of treatment for MA.

Comparison of head tilt test between sagging eye syndrome and acquired unilateral trochlear nerve palsy

PurposeTo investigate the distinction between sagging eye syndrome (SES group) and acquired unilateral trochlear nerve palsy (Trochlear group) in the Bielschowsky head tilt test (BHTT).MethodsFifteen patients in the SES group (mean age 74.6 ± 5.2 years) and 14 patients in the Trochlear group (55.2 ± 15.9 years) visited the Department of Ophthalmology, Hyogo Medical University Hospital between November 2016 and October 2022 for treatment of their diplopia. Eye position was measured with the alternate prism cover test, and values for fixation of the dominant eye, or unaffected eye, were used. Cyclodeviation was measured with the synoptophore and the Glaucoma Module Premium Edition of the SPECTRALIS optical coherence tomography. In the BHTT, eye position was measured in three head postures: primary position (PP), head tilt to the side with hypertropia (Hyper), and head tilt to the side with hypotropia (Hypo). The differences in vertical deviation between PP and Hyper (Hyper − PP), PP and Hypo (PP − Hypo) and Hyper − Hypo were measured and compared.ResultsVertical deviation in primary position was 7.3 ± 4.5 PD in the SES group and significantly larger (17.1 ± 8.4 PD) in the Trochlear group (p = 0.002). The vertical deviation in Hyper was significantly larger in the Trochlear group with 7.7 ± 4.7 PD and 22.1 ± 9.4 PD, respectively (p < 0.001), whereas the that in Hypo was not significantly different between the two groups with 6.5 ± 3.4 PD and 8.4 ± 6.6 PD, respectively (p = 0.725). The SES group showed no significant difference according to the 3 head postures (p = 0.311), while the Trochlear group showed a significantly different with smaller mean values in vertical deviation in Hypo (p < 0.001). The difference in the vertical deviation for the 3 head postures was the largest in Hyper − Hypo (1.7 ± 2.1 PD and 13.6 ± 7.1 PD, respectively), and the accuracy of SES was at the cutoff value of 6 PD, and it was considered not to be SES if the value was 6PD or higher. The accuracy of SES determination was 100% sensitivity and 100% specificity, and the area under the curve was 1.0.ConclusionThe difference in Hyper − Hypo in the BHTT may be the most useful index in differentiating SES from acquired unilateral trochlear nerve palsy; if the difference was more than 6 PD, the probability of SES was very low.

Examining the Relationship Between the Dominant Eye and the Dominant Hand

Background and Objectives: This study aims to determine the relationship between hand dominance and ocular dominance (OD) using different test formats of handedness and ocular dominance. Methods: Three OD test formats were administered to 74 healthy young adult subjects, hole-in-card test for sighting dominance, near-point-of-convergence (NPC) test for motor dominance, and +1.50 to blur test for sensory dominance. All of these tests were performed while the best correction was in front of the subject’s eyes. An interview for preferred dominance and a finger-tapping test for performance dominance were administered to determine the dominant hand. Results: Right eye dominance was indicated in 66.2% with the hole-in-card test, 56.8% with the NPC test, and 51.4% of cases with the +1.50-to-blur test. Statistically, a significant nonrandom relationship was observed between the results of hole-in-card and NPC tests (P=0.000), hole-in-card and +1.50-to-blur tests (P=0.003), and also between the results of NPC and +1.50-to-blur tests (P=0.003). In addition, it was found that in 52.7% of the cases, all three dimensions of eye dominance (sighting, sensory, and motor) are not in the same eye and do not have pure eye dominance. In examining the dominant hand, the majority of subjects were right-handed both in the preference (62 of 74 [83.8%]) and in the performance dimension (63 of 74 [85.1%]). Statistical analysis shows a significant nonrandom relationship between the pure dominant hand and the pure dominant eye (P=0.000). In addition, the pure dominant hand (0.813) and pure dominant eye (P=0.126) are independent of gender. Conclusion: Determining the OD, similar to determining the hand dominance based on their different dimensions, can have different results. According to the results, in all dimensions of ocular and hand dominance, both the dominant eye and the dominant hand are more on the right side of people. Furthermore, the pure dominant eye and pure dominant hand are not independent of each other.

Head Turn During Visual Field Testing to Minimize the Influence of Prominent Facial Anatomy.

Facial contour naturally decreases the visual field. Peripheral visual field defects caused by facial anatomy and ocular pathology can be missed in a routine standard of care. Mathematically calculating the true angle for turning the head to optimize the peripheral visual field has not been studied to date. The purpose of this study was to explore the utility of turning the head during perimetry to maximize the testable visual field. Six healthy study participants aged 18-52 were enrolled, prospectively; the dominant eye of each participant was tested. In total, 60-4 visual fields were obtained from each participant's dominant eye with the head in primary position. Then, the 60-4 tests were repeated with the head turned prescribed degrees toward and away from the tested eye ("manual method"). Based on a photograph of the participant's face, a convolutional neural network (CNN) was used to predict the optimal head turn angle for maximizing the field, and the test was repeated in this position ("automated method"). Maximal visual field exposure was found at a head turn of 15° away from the tested eye using the manual method and was found at an average head turn of 12.6° using the automated method; maximum threshold values were similar between manual and automated methods. The mean of threshold in these subjects at the standard direction and the predicted optimum direction was 1,302, SD = 69.35, and 1,404, SD = 67.37, respectively ( P = 0.02). Turning the head during perimetry maximizes the testable field area by minimizing the influence of prominent facial anatomy. In addition, our CNN can accurately predict each individual's optimal angle of head turn for maximizing the visual field.

Factors influencing dominant eye selection in refractive surgery patients: A correlation analysis

ObjectiveThis study aims to reveal the factors influencing the selection of the dominant eye in refractive surgery patients, and enhance the accuracy of clinical evaluation and surgical treatment. MethodsA retrospective study method was employed. The ocular biometric parameters were analyzed in 4,114 patients who underwent refractive surgery at the affiliated hospital of Southwest Medical University from 2019 to 2023. ResultsThe study found that 79.07% of the patients had the right eye as the dominant eye, while 20.93% had the left eye. Although there was no significant difference between the dominant and non-dominant eyes in terms of uncorrected visual acuity and Kappa angle, the dominant eye performed better in aspects such as spherical lens, eye axis, and corneal flat curvature. Furthermore, univariate and multivariate logistic regression results showed that best-corrected visual acuity, pupil diameter, horizontal displacement x-value of the Kappa angle, and astigmatism vector J45 were significant influencing factors for the selection of the dominant eye. ConclusionThere are numerous factors affecting the dominant eye, and the most important core factor is J45. This study comprehensively evaluated the possible factors affecting the dominant eye in patients undergoing refractive surgery, which provides a foundation for the designation of refractive surgical modalities and assurance of surgical outcomes, and opens up new perspectives on understanding the mechanisms of the formation and development of the dominant eye.

Optical coherence tomography profile of macular structure and ocular dominance in young adults

Optical coherence tomography profile of macular structure and ocular dominance in young adults

The effect of topical 1 % atropine on ocular dimensions and diurnal rhythms of the human eye

The effect of topical 1 % atropine on the diurnal rhythms of the human eye was investigated. Participants wore an activity monitor on Days 1–7. A set of measures (epochs) encompassing intraocular pressure (IOP), ocular biometry, and retinal imaging were obtained on Day 7 (baseline), followed by eight epochs on Day 8, and one on Day 9 from both eyes of healthy participants (n = 22, 19–25 years). The sleep time of participants (collected via actigraphy) was used as a reference in scheduling epochs. Topical 1 % atropine was instilled in the dominant eye on Day 8, 2 h after habitual wake time, using the fellow eye as control (paired-eye design). Sinusoids with a 24-h period were fitted to the data, and a non-linear mixed-effects model was used to estimate rhythmic statistics. There were no interocular differences in any of the measured parameters at baseline. Comparing pre- versus post-atropine in treated eyes revealed lower IOP, deeper anterior chamber (ACD), decreased crystalline lens thickness and shorter axial length (AL). The same trends were observed when comparing atropine-treated versus fellow control eyes, except for IOP and AL (no differences). Both atropine-treated and fellow control eyes showed significant diurnal variations in all ocular parameters, with atropine-treated eyes revealing larger AL and retinal thickness amplitudes, smaller vitreous chamber depth (VCD) amplitudes, and a significant phase advancement for ACD and VCD. There were no interocular differences in choroidal thickness rhythms. In conclusion, while ocular diurnal rhythms persisted after instillation of 1 % atropine, many rhythmic parameters were altered.

Unilateral intraindividual comparison and bilateral performance of a monofocal spherical and diffractive extended depth of field intraocular lens mix-and-match approach.

To evaluate the intraindividual visual performance of a spherical and extended depth of field (EDOF) IOL used in a mix-and-match approach. Single centre (tertiary care centre), retrospective consecutive case series. Included patients had uneventful cataract surgery with implantation of a spherical monofocal IOL (CT Spheris 204) in the dominant eye and a diffractive EDOF IOL (AT LARA 829) in the non-dominant eye. Monocular and binocular defocus curves and visual acuity at various distances were assessed. In addition, binocular reading speed, contrast sensitivity, and patient satisfaction using QOV, Catquest 9SF, and glare/halo questionnaires are reported. A total of 29 patients (58 eyes) were included. We observed significant intra-individual differences for monocular DCIVA, DCNVA, UIVA, and UNVA. There were no differences in monocular BCDVA or UDVA. The monocular defocus curves for the two IOLs significantly differed at defocus steps between -1.0 and -3.5 D. 93.10% of patients reported they would opt for the same combination of IOLs. Excellent uncorrected and corrected distance visual acuity was demonstrated in both groups. The mix-and-match approach described in this study yielded good intermediate vision and improved near vision with high-patient satisfaction.

Resistance Toward Subordination of Women in The Breadwinner Novel by Deborah Ellis: A Feminist Study

This research aimed to discover the resistance and the subordination forms. The method used is descriptive qualitative research method and feminism approach applied specifically Simone de Beauvoir's notions of The Otherness in The Second Sex book. The data gathered through attentive reading and observation of the narration, mono – dialogue, and characters' actions in The Breadwinner novel by Deborah Ellis. Furthermore, the writers determined that women have a difficult access to work as a result of discrimination and exploitation, married women are required to be completely subservient to their husbands, unequal education opportunity, parents expected a son over a daughter, and women unable to participate in social-political activities. Also, on Beauvoir ideas of resist toward The Otherness such as women can work, become intellectuals, contribute to a socialist revolution, and women can transcend their limitations by refusing to internalize their otherness or to identify themselves through the dominant group's eyes. This can be concluded that women still faced severe discrimination, oppression, exploitation, and inequality to gain their freedom, yet women still resist to the oppression in society.

Exploring the Association Between Trunk Asymmetry and Dominance Preference

Background: Trunk asymmetry, an indicator of potential scoliosis, manifests as an uneven distribution in body alignment such as shoulder, head, and hip positions. An individual's inherent preference to use one side of the body over the other, known as laterality, may contribute to such imbalances. This study aimed to explore the correlation between trunk asymmetry and side preference in adults, particularly in relation to hand, foot, ear, and eye dominance. Methodology: In this cross-sectional study, 164 young adults aged 18-25 were screened using the Adam’s forward bend test. Data collection encompassed three phases: demographic and anthropometric data collection (Phase 1), a visual inspection for head tilt, shoulder and pelvic asymmetry, and spinal curvature deviation (Phase 2), and an assessment of side dominance using a 16-item lateral preference inventory questionnaire (Phase 3). Results: Hand dominance correlated significantly with head tilt (p &lt; 0.01), shoulder asymmetry (p &lt; 0.05), and ear asymmetry (83.5% concordance), while foot dominance was associated with pelvic tilt (57.3% concordance). Eye dominance showed a 65.9% concordance with ear asymmetry, and ear dominance was linked to head tilt and shoulder asymmetry (81.7% and 94.5% concordance, respectively). Spinal curve deviation displayed a chi-square value of 3.158 (p &lt; 0.05) with hand dominance and 4.321 (p &lt; 0.05) with foot dominance. Conclusion: The study establishes a significant association between trunk asymmetry and dominance preference. These findings advocate for the integration of laterality assessments in the clinical evaluation of trunk asymmetry to potentially enhance diagnostic accuracy and inform therapeutic approaches.

Contributed Session III: Active vision shapes ocular dominance.

Ocular dominance is a basic visual property that shows short-term plasticity in adult humans, where 2h of monocular deprivation leads to a homeostatic shift of ocular dominance in favour of the deprived eye. Using an altered reality setting, we found that this homeostatic plasticity can be triggered without depriving one eye of visual input, but merely perturbing the temporal correspondence between voluntary actions and vision in one eye. Participants wore a VR set; its monocular screens were connected with cameras monitoring the front space, which participants used to perform a complex visuomotor task. During a 60 minute period, the input to the dominant eye was delayed by 333 ms, making it useless for visuomotor coordination. Following this, ocular dominance (quantified by binocular rivalry) was systematically shifted in favour of the delayed eye, a similar effect as that produced by monocular contrast-deprivation. The shift was only observed when participants actively engaged in the visuomotor task, not when they passively watched a confederate perform the same task. We interpret these results in the light of parallel fMRI experiments where monocular deprivation is associated with a global system reconfiguration that pivots around a key area for sensorimotor integration, the Pulvinar. Based on our findings, we suggest that active vision is foundational to weighting sensory information, even at the level of simple visual processes as those setting ocular dominance.

Deficits in Reach Planning and On-Line Grasp Control in Adults With Amblyopia.

Adults with amblyopia exhibit impairments when reaching to grasp three-dimensional objects. We examined whether their deficits derive from problems with feedforward planning of these prehension movements or in using visual feedback to control them on-line. Twenty-one adults with mild to severe anisometropic and/or strabismic amblyopia and reduced binocularity participated, along with 21 normally sighted age- and gender-matched controls. Subjects used their preferred hand to reach for, precision grasp, and then lift cylindrical table-top objects (two sizes, two distances) using binocular, dominant eye, or amblyopic/non-sighting eye vision just to plan their movements during a 1-second task preview with vision then occluded so feedback was absent or to plan and execute them (i.e., with visual feedback fully available). Kinematic and error measures of the timing and accuracy of the reach and grasp were quantified by view and feedback and compared by ANOVA. The amblyopic adults performed generally worse than controls across all three views in both feedback conditions. With vision for planning only, their movement initiation and duration times were significantly increased, as were their initial reach times and error rates, especially when using the amblyopic eye alone, whatever its visual acuity loss. These relative planning deficits were only partially rectified with visual feedback available on-line. Relative grasp planning deficits were less evident in the amblyopia group, who instead produced significantly increased grip times and errors under binocular and amblyopic eye visual feedback conditions, although the subgroup with unmeasurable stereovision also formed wider (inaccurate) grasps across all conditions. Adults with amblyopia seem to have problems constructing reliable internal spatial representations for the feedforward planning of prehension, particularly with their affected eye and mainly affecting their reach, with additional deficits in on-line grasp control related to poor binocularity.

Digital Pupillometry and Centroid Shift Changes in Dominant and Nondominant Eyes.

To investigate the differences between dominant and nondominant eyes in a predominantly young patient population by analyzing the angle kappa, pupil size, and center position in dominant and nondominant eyes. A total of 126 young college students (252 eyes) with myopia who underwent femtosecond laser-combined LASIK were randomly selected. Ocular dominance was determined using the hole-in-card test. The WaveLight Allegro Topolyzer (WaveLight Laser Technologies AG, Erlangen, Germany) was used to measure the pupil size and center position. The offset between the pupil center and the coaxially sighted corneal light reflex (P-Dist) of the patients was recorded by the x- and y-axis eyeball tracking adjustment program of the WaveLight Eagle Vision EX500 excimer laser system (Wavelight GmbH). The patient's vision (uncorrected distance visual acuity [UDVA], best-corrected visual acuity (BCVA), and refractive power (spherical equivalent, SE) were observed preoperatively, 1 week, 4 weeks, and 12 weeks postoperatively, and a quality of vision (QoV) questionnaire was completed. Ocular dominance occurred predominantly in the right eye [right vs. left: (178) 70.63% vs. (74) 29.37%; p < 0.001]. The P-Dist was 0.202 ± 0.095 mm in the dominant eye and 0.215 ± 0.103 mm in the nondominant eye (p = 0.021). The horizontal pupil shift was - 0.07 ± 0.14 mm in dominant eyes and 0.01 ± 0.13 mm in nondominant eyes (p = 0.001) (the temporal displacement of the dominant eye under mesopic conditions). The SE was negatively correlated with the P-Dist (r = - 0.223, p = 0.012 for the dominant eye and r = - 0.199, p = 0.025 for the nondominant eye). At 12weeks postoperatively, the safety index (postoperative BDVA/preoperative BDVA) of the dominant and nondominant eyes was 1.20 (1.00, 1.22) and 1.20 (1.00, 1.20), respectively, and the efficacy index (postoperative UDVA/preoperative BDVA) was 1.00 (1.00, 1.20) and 1.00 (1.00, 1.20), respectively; the proportion of residual SE within ± 0.50 D was 98 and 100%, respectively. This study found that ocular dominance occurred predominantly in the right eye. The pupil size change was larger in the dominant eye. The angle kappa of the dominant eye was smaller than that of the nondominant eye and the pupil center of the dominant eye was slightly shifted to the temporal side under mesopic conditions. The correction of myopia in the dominant and nondominant eyes exhibits good safety, efficacy, and predictability in the short term after surgery, and has good subjective visual quality performance after correction. We suggest adjusting the angle kappa percentage in the dominant eye to be lower than that of the nondominant eye in individualized corneal refractive surgery in order to find the ablation center closest to the visual axis.

A Novel Prediction Method for Glaucoma Detection Using Retinographies.

Glaucoma, characterized by its damage to the retinal nerve, is one of the most statistically dominant eye diseases in the U.S. It can cause vision loss and blindness by affecting the optic nerve. As the disease progresses, it is not necessarily noticeable to patients, requiring elaborate solutions to manage this critical condition. In this paper, we propose a novel detection model that provides improved accuracy and performance in the detection of glaucoma using retinographies as input. After careful consideration, we adopted multiple features suitable for distinguishing healthy and diseased eyes. Moreover, the adoption, integration, and feature extraction of 3D meshes was a significant factor in developing our glaucoma detection system. With our acquired dataset, we compared the performance of Classification Decision Trees (CDT), Support Vector Machine (SVM), and K-Nearest Neighbor (KNN) in classifying retinographies as being healthy or having glaucoma. Experimental results show that the proposed model methodology can efficiently predict glaucoma detection with 100%, 100%, and 83.3% accuracy from CDT, SVM, and KNN, respectively.

The role of botulinum toxin in management of infantile esotropia

Purpose: To find out the effect of a single dose botulinum toxin injection. Methods: This study is an observational case series. Data of patients with infantile esotropia who received a single dose of botulinum toxin in 6th-9th month of their age were retrospectively reviewed during the period from February 2013 to January 2015. Botulinum toxin was injected in each of medial recti with a dose of 5 IU/0,05 mL without Electromyography (EMG) control. Five patients were included in the study. Complications reletad to injection and to the toxin were recorded. During their regular follow-ups, the parents were instructed to patch the dominant eye if there is fixation preference either in exotropia or esotropia phases. Patients were examined between their 72nd to 96th month to find out their current visual acuity and to observe if they had any late term accompanying squints, nystagmus and amblyopia. Snellen optotypes or pictures were used for detecting best-corrected visual acuity. Results: Orthophoria was the main outcome for 3 of the 5 patients. Dissociated deviations and latent nystagmus did not develop on any patient. On the last examination, patients’ visual acuities were assesed. Orthophoric ones: One patient had 1.0/1.0 visual acuity, one patient had 0.4/0.6 visual acuity, one patient had 0.2/0.2 visual acuity. Monocular esotropia ones: On the strabismic eye 0.1, on the dominant eye 1.0 visual acuity was detected. Inferior oblique muscle hyperfunction developed post injection on all the patients. Conclusions: Botulinum toxin injection caused infantile esotropia to change into a more manageble form.

Comparison of different methods used in balance evaluation in children with diparetic cerebral palsy

ABSTRACTPurposeIn this study, we aimed to investigate the validity and reliability of Single Leg Stance (SLS), Tandem Stance (TS) and Pediatric Reach Tests (PRT) in children with Cerebral Palsy (CP).MethodsFifty-three children (31 boys, 22 girls, age:3-15 years, Gross Motor Function Classification System (GMFCS) Level I- II with diparetic CP were included the study. SLS, TS, PRT test used for balance evaluations. SLS test was made by standing on dominant (D) and non-dominant (ND) extremity both eyes opened (EO) and closed (EC).ResultsThe mean age of childrens were 7.88±3.43 years. The Cronbach’s - coefficients of all tests used to evaluate the internal consistency were found to excellent to acceptable level. SLS-D with EO/ EC, SLS-ND with EO/ EC and TS with EO had strong correlation, TS with EC and PRT-Forward moderate correlation, PRT-Right and eft low correlation with GMFCS. All tests except PRT-Right and PRT-Left were discriminate balance ability between GMFCS level I and level II (AUC>0.800).ConclusionIn this study, we used SLS, TS, PRT for balance evaluations and we investigated reliability and validity (construct and predictive) of each balance tests in childeren with diparetic CP. All tests were sensitive in distinguishing between GMFCS levels I and II, except PRT-Right and PRT-Left. As a result of the study, it was determined that the tests were valid and reliable, suggesting that physiotherapists will provide clinical advantage in order to quickly learn about the balance of children with CP.

Electrophysiological Evidence of Stroboscopic Training in Elite Handball Players: Visual Evoked Potentials Study.

Stroboscopic training enhances perceptual cognition and motor skills; however, neurophysiological mechanisms underlying this adaptation are not fully understood. This study aimed to investigate the effects of a six-week stroboscopic training program on the conductivity of the visual pathway in elite handball players, specifically related to their visual processing of retinal location and viewing conditions. The study included 22 handball players who were randomly assigned to an experimental or a control group. Both groups performed handball-specific in-situ tasks, but only the experimental group underwent stroboscopic training. Participants were assessed three times using visually evoked potential recordings measured by P100 implicit time and amplitude under three viewing conditions (dominant eye, non-dominant eye, and binocular) and two retinal locations (extra-foveal and foveal vision) before and after the six-week training period, and again four weeks later. The results showed a significant TIME vs. GROUP effect of P100 implicit time for the dominant eye in extra-foveal vision (F2,40 = 5.20, p = 0.010, ηp2 = 0.206), extra-foveal binocular viewing (F2,40 = 3.32, p = 0.046, ηp2 = 0.142), and dominant eye foveal vision (F2,40 = 4.07, p = 0.025, ηp2 = 0.169). Stroboscopic training significantly improved early visual processing by reducing the P100 implicit time for the dominant eye and binocular vision, particularly in extra-foveal vision. The improvements were more noticeable in the short compared to the long term.

Thalamic regulation of ocular dominance plasticity in adult visual cortex

Experience-dependent plasticity in the adult visual system is generally thought of as a cortical process. However, several recent studies have shown that perceptual learning or monocular deprivation can also induce plasticity in the adult dorsolateral geniculate nucleus (dLGN) of the thalamus. How plasticity in the thalamus and cortex interact in the adult visual system is ill-understood. To assess the influence of thalamic plasticity on plasticity in primary visual cortex (V1), we made use of our previous finding that during the critical period ocular dominance (OD) plasticity occurs in dLGN and requires thalamic synaptic inhibition. Using multielectrode recordings we find that this is also true in adult mice, and that in the absence of thalamic inhibition and plasticity, OD plasticity in adult V1 is absent. To study the influence of V1 on thalamic plasticity, we silenced V1 and show that during the critical period, but not in adulthood, the OD shift in dLGN is partially caused by feedback from V1. We conclude that during adulthood the thalamus plays an unexpectedly dominant role in experience-dependent plasticity in V1. Our findings highlight the importance of considering the thalamus as a potential source of plasticity in learning events that are typically thought of as cortical processes.