Eye and Brain最新文献

Ocular dominance plasticity, the ability of the brain to change sensory eye balance, has traditionally been believed to be extremely limited in adult visual cortex. However, recent studies on short-term monocular deprivation (MD) demonstrate that its presence is prevalent in adult humans, as short-term MD is capable of significantly shifting ocular dominance in favor of the previously deprived eye. Thus, findings over the last 15 years highlight that short-term MD can be a promising alternative treatment for amblyopia, a neurodevelopmental disorder characterized by binocular imbalance. Conventionally, amblyopia has been treated with patching therapy, which shows limited effectiveness in restoring binocularity of adults and is associated with poor compliance rate and high psychosocial distress. Thus, it is an opportune time to explore how short-term MD can be utilized as an alternative treatment option for restoring amblyopic vision, especially individuals who do not respond robustly to standard treatment. This review provides an overview of foundational studies on ocular dominance plasticity in both visually intact and impaired observers. It also evaluates the potential of short-term MD as a treatment for amblyopia and suggests its future research directions, including the integration of multimodal therapeutic strategies that include short-term MD.

Concussions are a mild form of traumatic brain injury (TBI) that is typically self-limited and transient with a high prevalence within our communities. Due to the vast visual network interconnectivity, visual symptoms secondary to a concussion occur about 90% of the time. A gold standard to confirm concussion acutely has not been well established. Visual function testing based on symptoms remains the standard of care in off-site evaluation for diagnosis of oculomotor dysfunction. This review covers the current diagnostic strategies for vision based disorders post-concussion for sideline testing, off-site testing, and research driven testing.

Purpose: This study investigated the relationships between structural and functional parameters in non-arteritic ischemic optic neuropathy (NAION).

Methods: This retrospective study enrolled 29 patients (58.2 ± 10.4 years old) with unilateral NAION. During the acute phase, we performed comprehensive evaluations including best-corrected visual acuity (BCVA), optical coherence tomography (OCT), optical coherence tomography angiography (OCTA), visual fields (VF), visual evoked potentials (VEP), electroretinography (ERG), and multifocal ERG (mf-ERG). At three months post-presentation, patients underwent follow-up assessments comprising visual acuity testing, perimetry, and advanced retinal imaging.

Results: During the acute phase, affected eyes demonstrated increased mean retinal nerve fiber layer (RNFL) thickness, while ganglion cell-inner plexiform layer (GCIPL) thickness decreased. Both visual fields mean deviation (MD) and VEP P100 amplitude were reduced, accompanied by prolonged peak latency. We also observed decreased P1 response density in mf-ERG. Analysis revealed significant direct correlations between GCIPL parameters and electrophysiological measurements, particularly VEP P100 amplitude and mf-ERG P1 response density. Mean GCIPL thickness, VF MD, and VEP P100 amplitude showed negative correlations with baseline logMAR VA. Baseline VF MD, VEP P100 amplitude, and minimum GCIPL thickness showed negative correlations with logMAR VA at 3-month follow-up.

Conclusion: Retinal ganglion cell layer thickness serves as a valuable indicator to objective evaluate optic nerve function in acute NAION patients. Decreases in both VEP amplitude and mf-ERG response density showed significant correlations with retinal ganglion cell layer thickness. Baseline visual field performance, VEP measurements, and minimum GCIPL thickness exhibited negative correlations visual acuity at 3-month follow-up.

Trial registration: Clinical Research Ethics Committee of Xi'an People's Hospital (NO. 20220018). Registered 27 September 2022-Retrospectively registered, https://www.medicalresearch.org.cn/. Informed consent was obtained from each participant.

Introduction: Visual Snow Syndrome (VSS) is characterized by the presence of dynamic, continuous, tiny dots in the entire visual field persisting for more than three months, with at least two associated symptoms- palinopsia, photopsia, photophobia, or nyctalopia. VSS was introduced as perpetual visual disturbance representing TV static, based on early case reports from 1995. Despite its recognition, VSS management remains vague as many cases are refractory to treatment. This literature review aims to provide a summary of all attempted treatments and efficacies to help physicians manage VSS.

Methods: The authors performed a search of articles, literature reviews, and case reports using PubMed and Google Scholar with the key words "visual snow" and "treatment". Forty-one publications were identified; however, 14 were excluded as they did not discuss treatment options or focused on medical conditions associated with visual snow, such as migraine with aura. 27 articles were found to be relevant (from 1999-2024) with treatments in patients officially diagnosed with VSS. Treatments included pharmacotherapy, tinted lenses, neuromodulation, and behavioral therapy.

Results: Based on this review of 27 publications, benzodiazepines and lamotrigine had the best effect (71.4% and 61.5% of patients had an improvement of VS symptoms on each medication, respectively). Antidepressants and AV nodal blocking agents were frequently prescribed but were less effective. VS symptoms improved with filtered lenses combined with cognitive behavioral therapy. Most treatments only partially alleviate VSS or manage associated symptoms like headache and palinopsia, rather than the visual snow itself.

Conclusion: The subjective nature of VSS has posed challenges. Among pharmacological treatments, benzodiazepines and lamotrigine have the most favorable therapeutic ratio in managing VSS. FL-41 tinted lenses consistently provide symptom relief, with cognitive behavioral therapy showing promise as an emerging intervention. Due to the small sample size, further research is recommended to enhance the applicability of findings.

Purpose: Animal studies have suggested that visual degradation impacts eye growth due to the attenuation of high spatial frequencies. However, the influence of perceptual visibility remains unclear in humans. The aim of this study was to investigate the impact of visibility on visual attenuation-related eye changes during reading.

Methods: Axial length (AxL) and choroidal thickness (ChT) changes associated with reading tasks were measured in two separate experiments. In the first experiment, the reading task was conducted under different forms of visual attenuation (contrast, resolution, defocus, noise, and crowding). For each form of visual attenuation, the text was set at a sub-threshold level of visibility, evaluated via prior measurement of reading performance, and kept constant via adaptive control of the intensity of the stimulation. Each sub-threshold reading condition was compared with a supra-threshold reading text, serving as control. In the second experiment, the effect of visibility on lens-induced defocus was further examined by comparing the effect of text stimulation with an equivalent dioptric of 5.5 D under sub- and supra-threshold levels of resolution.

Results: Near distance reading with supra-threshold texts caused eye elongation (AxL: +12.942 µm ± 2.147 µm; ChT: -3.192 µm ± 1.158 µm). Additional defocusing failed to exacerbate axial elongation under sub-threshold text visibility (mean difference: -0.135 µm ± 2.783 µm), revealing a clear inhibitory effect of lowering visibility on eye changes. Other forms of visual degradation, including crowding (mean difference: 6.153 µm ± 2.127 µm) and noise (mean difference: 5.02 µm ± 2.812 µm) also showed an inhibitory effect on eye elongation. The significant effect of crowding indicated that post-retinal mechanisms, involving attentional processes related to crowded characters, may play a role in the influence of visibility.

Conclusion: Although the featural composition of visual stimulation can drastically influence eye changes, this study revealed an important mediating role of visibility, previously underscored in chick studies, which warrants further explorations of the impact of post-retinal processes in eye growth.

Purpose: Visual System Homeobox 2 (Vsx2) is a transcription factor expressed in the developing retina that regulates tissue identity, growth, and fate determination. Several mutations in the Vsx2 gene exist in mice, including a spontaneous nonsense mutation and two targeted missense mutations originally identified in humans. Here, we expand the genetic repertoire to include a LacZ reporter allele (Vsx2^LacZ ) designed to express beta-Galactosidase (bGal) and simultaneously disrupt Vsx2 function (knock-in/knock-out).

Methods: We generated a Vsx2^LacZ reporter allele with an in-frame fusion to the Vsx2 coding sequence immediately following exon 2. Germline transmission was assessed with genomic DNA PCR and Western blot analysis was used to describe VSX2 expression from the mutant allele (LacZ). Eye size quantification and immunohistology were used to describe the embryonic and postnatal retinal phenotypes of LacZ homozygous and heterozygous mice. The contribution of Mitf to LacZ mutant microphthalmia was probed with the semi-dominant negative Mitf^mi allele.

Results: The retinal expression pattern of bGal is concordant with VSX2, and the mutant allele is recessive. Vsx2^LacZ homozygous mice have congenital bilateral microphthalmia accompanied by defects in retinal development including ectopic expression of non-retinal genes, reduced proliferation, delayed neurogenesis, aberrant tissue morphology, and an absence of bipolar interneurons - all hallmarks of Vsx2 loss-of-function. The Mitf^mi allele reduced the severity of microphthalmia caused by the Vsx2^LacZ allele. Unexpectedly, the mutant VSX2 protein is stably expressed, and there are subtle differences in eye size and early retinal neurogenesis when compared to the null mutant, ocular retardation J.

Conclusion: The perdurance of the mutant VSX2 protein combined with subtle deviations from the null phenotype leaves open the possibility that Vsx2^LacZ allele is not a complete knock-out. The Vsx2^LacZ allele exhibits loss-of-function characteristics and adds to the genetic toolkit for understanding Vsx2 function.

Purpose: To investigate the presence of peripapillary retinal nerve fiber layer (pRNFL) degeneration in patients with late-infantile neuronal ceroid lipofuscinosis type 2 (CLN2) disease and to evaluate the role of optical coherence tomography (OCT) assessed pRNFL thickness as a biomarker for CLN2 disease progression.

Patients and methods: Forty eyes of 20 patients with genetically and enzymatically confirmed diagnosis of late-infantile CLN2 disease were included in this retrospective cohort study. All patients received 300 mg of intracerebroventricular enzyme replacement treatment (cerliponase alfa) once every two weeks. OCT imaging was performed under general anesthesia using spectral domain OCT (Heidelberg Engineering, Heidelberg, Germany). PRNFL thickness and central retinal thickness (CRT) values were manually confirmed with the Heidelberg Eye Explorer software. Corresponding pediatric data were extracted from the DEM-CHILD database. Spearman correlation coefficient values (rs) were calculated between pRNFL and CRT values, age at examination, the Weill Cornell Late Infantile Neuronal Ceroid Lipofuscinosis (Weill Cornell LINCL) Scale and the Hamburg Motor and Language (HML) Scale.

Results: Fourteen of 20 patients underwent serial examinations resulting in a total of 84 OCT Scans and 42 Weill Cornell LINCL and HML Scale scores. Mean age was 6.90 years and mean follow-up time was 1.38 years. Mean global pRNFL (G-pRNFL) thickness was 77.02 μm presenting a significant decrease compared to normative values from healthy children (106.45 μm; p < 0.0001). G-pRNFL displayed significant correlations towards age at examination (r_s = - 0.557, p < 0.01), the Weill Cornell LINCL Scale (r_s = 0.849, p < 0.01), and the HML Scale (r_s = 0.833, p < 0.01). Repeated measurements indicated decreases in pRNFL thickness over time in most patients.

Conclusion: Patients with late-infantile CLN2 disease exhibit early onset progressive pRNFL loss regardless of outer retinal degeneration, highlighting the potential of pRNFL as an independent ocular biomarker for retinal pathology in late-infantile CLN2 disease.

Purpose: To characterize ocular motility disturbances through Microperimetry (MP) in patients with Multiple Sclerosis (MS) trying to detect those capable of influencing the disability to improve the accuracy of assessing visual impact in EDSS scale. MP results were compare with some structural parameters obtained by OCT.

Patients and methods: Cross-sectional analytical and correlational case-control study approved by Ethical Committee. A total of 82 eyes (41 patients) and 30 healthy eyes (15 subjects) were enrolled after informed consent. All participants underwent ophthalmological evaluation with MP and OCT. Variables included MS disease duration, Expanded Disability Status Scale (EDSS) score; in OCT: central macular thickness (CMT), ganglion cell-inner plexiform layer thickness (GCIPL), and peripapillary retinal nerve fiber layer thickness (pRNFL); and in MP: test duration, reaction time, average macular threshold (AT), and 4 fixation stability indexes (P1, P2, BCEA63, BCEA95).

Results: MS group showed a significant decrease in GCIPL (p < 0.001) and pRNFL thickness (p < 0.001) compared to the control group. Furthermore, patients demonstrated a longer examination (p < 0.001) and reaction (p < 0.001) times, reduced AT (p < 0.001), more unstable fixation indexes (P1 p <0.004, P2 p = 0.018, BCEA63 p = 0.005 and BCEA95 p = 0.007), measured by MP. In addition, patients with a history of ON (n=16) demonstrated longer examination times in MP (p = 0.049) compared to MS patients without ON, but they were not correlations with OCT measurements, EDSS score correlated with the CMT (p = 0.023, r = -0.25), MP duration (p = 0.043, r = 0.22), and fixation indexes (P1 p = 0.049, r = -0.22, BCEA63 p = 0.041, r = 0.23, BCEA95 p = 0.049, r = 0.22).

Conclusion: Our study emphasizes the complementary utility of MP and OCT in assessing MS patients. Additionally, it highlights that using MP for objective measurements of oculomotor dysfunction could improves accuracy in disability assessment on the EDSS scale.

Purpose: The impact of visual deprivation on retinal structure is widely debated. Experimental models, like monocular deprivation through lid suture, provide insights into the consequences of lacking visual experience during development. This deprivation delays primary visual cortex (CV1) maturation due to improper neural connection consolidation, which remains plastic beyond the critical period. However, few studies have used Optical Coherence Tomography (OCT) to investigate structural alterations in the retina of animal models following monocular deprivation. Instead, some studies have focused on the ganglion cell layer using post-mortem histological techniques in amblyopia models induced by monocular deprivation.

Methods: In this study, we used Cliff test to assess stereoscopic vision and spectral domain optical coherence tomography (SD-OCT) to evaluate retinal changes in an in vivo model of visual deprivation treated with Transcranial Direct Current Stimulation (tDCS).

Results: The depth perception test initially revealed differences between individuals with amblyopia and the control group. However, after 8 tDCS sessions, amblyopic subjects matched the control group's performance, which remained stable Additionally, significant changes were observed in retinal structures post-tDCS treatment. Specifically, the thickness of the Nerve Fiber Layer + Ganglion Cell Layer + Inner Plexiform Layer (NFL+GCL+IPL) increased significantly in amblyopic eyes (p<0.001). Moreover, significant retinal thickening, including the Nerve Fiber Layer + Ganglion Cell Layer + Inner Plexiform Layer (NFL+GCL+IPL) and the entire retina, was observed post-tDCS treatment (p<0.05), highlighting the critical role of tDCS in ameliorating amblyopia. Additionally, treated animals exhibited reduced thickness in the Inner Nuclear Layer (INL) and Outer Nuclear Layer (ONL).

Conclusion: tDCS treatment effectively restores amblyopic individuals' stereoscopic vision, aligning their performance with controls, while impacting retinal structure, highlighting its potential in ameliorating amblyopia's visual deficits.

Purpose: To evaluate the use of delay alternating with nutation for tailored excitation-prepared T1-weighted turbo spin echo (DANTE T1-SPACE) imaging for diagnosing optic neuritis and to analyze its correlation with clinical findings before and after treatment.

Patients and methods: Patients diagnosed with optic neuritis or non-arteritic anterior ischemic optic neuropathy (NA-AION) were evaluated at the Ophthalmology Department of Kyoto University Hospital. All patients underwent magnetic resonance (MR) studies before treatment initiation and ophthalmic examinations before and after treatment. Three ophthalmologists independently reviewed the MR scans for abnormalities. The magnetic resonance imaging (MRI) assessments included post-contrast DANTE T1-SPACE, post-contrast volumetric interpolated breath-hold examination (VIBE), and short T1 inversion recovery (STIR) scans. The presence of abnormalities in each sequence was determined.

Results: Of 36 eyes from 30 patients, 21 eyes from 17 patients were diagnosed with optic neuritis, and 15 eyes from 13 patients were diagnosed with NA-AION. DANTE T1-SPACE sequences showed better sensitivity for detecting optic neuritis than STIR sequences (100% vs 67%, p = 0.009). VIBE images did not confirm enhancement of lesions in some cases with optic neuritis. No differences were observed among the sequences for NA-AION. Lesion length evaluated by DANTE T1-SPACE sequences was associated with circumpapillary retinal nerve fiber layer thickness at the initial visit, eye pain, and the time interval from symptom onset to MRI scan.

Conclusion: Contrast-enhanced DANTE T1-SPACE was better than other sequences of MRI for diagnosing optic neuritis.