Decline In Visual Function Research Articles

Longitudinal Changes of Visual Sensitivity With Geographic Atrophy Progression Assessed by Defect-Mapping Microperimetry.

To determine the relationship between structural and functional changes over time in the progression of geographic atrophy (GA) as assessed by defect-mapping microperimetry, an approach optimized to characterize the spatial extent of deep visual sensitivity losses. A total of 57 eyes from 50 participants underwent defect-mapping microperimetry testing of the central 8° radius (with a 10-dB stimuli presented once each at 208 locations) over a median of five visits, scheduled at 3-monthly intervals. GA lesion(s) on fundus autofluorescence in the corresponding region tested on microperimetry at each visit were manually annotated. At a global level, change of GA extent in the central 8° radius explained a large proportion of the variance in the change in the proportion of locations missed (nonresponse) on defect-mapping microperimetry (R2 = 0.52). Locally, test locations that were entirely outside or within GA lesion(s) had a 0.3% (P = 0.305) and 2.3% (P < 0.001) probability of worsening between the two visits, respectively. In contrast, test locations with a 0% to 25%, 25% to 50%, 50% to 75%, or 75% to 100% change in the extent of GA overlapping between visits had a 4.1%, 12.0%, 17.5%, and 37.9% probability of worsening, respectively (all P < 0.001). This study confirms that longitudinal changes in GA extent are associated with functional changes on defect-mapping microperimetry, both on a global and local level. These findings highlight the expected functional relevance of GA progression, and demonstrates the potential effectiveness of this microperimetry testing strategy for capturing visual function decline associated with GA progression.

AIBP Protects Müller Glial Cells Against Oxidative Stress-Induced Mitochondrial Dysfunction and Reduces Retinal Neuroinflammation.

Glaucoma, an optic neuropathy with the loss of retinal ganglion cells (RGCs), is a leading cause of irreversible vision loss. Oxidative stress and mitochondrial dysfunction have a significant role in triggering glia-driven neuroinflammation and subsequent glaucomatous RGC degeneration in the context of glaucoma. It has previously been shown that apolipoprotein A-I binding protein (APOA1BP or AIBP) has an anti-inflammatory function. Moreover, Apoa1bp-/- mice are characterized by retinal neuroinflammation and RGC loss. In this study, we found that AIBP deficiency exacerbated the oxidative stress-induced disruption of mitochondrial dynamics and function in the retina, leading to a further decline in visual function. Mechanistically, AIBP deficiency-induced oxidative stress triggered a reduction in glycogen synthase kinase 3β and dynamin-related protein 1 phosphorylation, optic atrophy type 1 and mitofusin 1 and 2 expression, and oxidative phosphorylation, as well as the activation of mitogen-activated protein kinase (MAPK) in Müller glia dysfunction, leading to cell death and inflammatory responses. In vivo, the administration of recombinant AIBP (rAIBP) effectively protected the structural and functional integrity of retinal mitochondria under oxidative stress conditions and prevented vision loss. In vitro, incubation with rAIBP safeguarded the structural integrity and bioenergetic performance of mitochondria and concurrently suppressed MAPK activation, apoptotic cell death, and inflammatory response in Müller glia. These findings support the possibility that AIBP promotes RGC survival and restores visual function in glaucomatous mice by ameliorating glia-driven mitochondrial dysfunction and neuroinflammation.

The reduction of LEDD leads to visual dysfunction in patients with PD after STN-DBS: a randomized clinical trial

Background: Medication adjustment after deep brain stimulation (DBS) of the subthalamic nucleus (STN) in patients with Parkinson’s disease (PD) may influence visual function. However, no clinical trials have been designed specifically to investigate this effect. Objectives: To compare the effects of levodopa equivalent daily dose (LEDD) reduction and non-reduction on visual function in patients with Parkinson’s disease (PD) following STN-DBS. Methods: This was a multi-center, prospective, randomized, double-blinded clinical trial. A total of 208 patients with Parkinson’s disease were referred for DBS between June 2019 and July 2021 and analyzed between June 2023 and July 2023. STN-DBS was performed, and the LEDD was reduced in one study arm but not in the other. The primary outcome measure was visual impairment in Parkinson’s disease questionnaire (VIPD-Q) with or without LEDD reduction 12 months postoperatively, and the secondary outcomes included retinal nerve fiber layer (RNFL) thickness, vessel density, eye-tracking system results, contrast sensitivity and visual field. Results: During the short-term follow-up, DBS implantation and stimulation did not significantly affect visual function (VIPD-Q, baseline vs. 1 month, 9.269±8.385 vs. 8.938±7.666, Mann–Whitney U tests; P=0.6746). In the long-term follow-up, the reduction group demonstrated a significant decline in visual function, RNFL thickness, and vessel density after STN-DBS compared with the control group without STN-DBS (P&lt;0.001). Conclusions: Visual dysfunction, particularly a thinner RNFL and lower vessel density, is related to LEDD reduction after STN-DBS. Prolonged administration of dopamine-mimetic drugs prevents visual symptoms. Thus, physicians should consider LEDD adjustment when patients report visual dysfunction before surgery or severe visual symptoms after STN-DBS.

Morphometric, immunohistochemical and ultrastructural examination of age-related structural alterations in optic nerve

Aims: As individuals age, there is a known decline in visual function attributed to a reduction in the optic nerve fibers and myelin sheath degeneration. Studies present conflicting findings on whether aging affects axonal integrity in the human optic nerve. This study aims to investigate degenerative changes in the aging rat optic nerve. Methods: The investigation involved 36 Wistar albino rats. The rats were divided into six groups: the newborn, prepubertal, pubertal, junior, adult, and elderly groups. This study investigated optic nerve axon counts, axon diameters, levels of glial fibrillary acidic protein immunoreactivity (GFAP-IR) and nerve growth factor immunoreactivity (NGF-IR), as well as findings from light microscopy (LM) and electron microscopy (EM) in these groups. Results: This study observed age-related alterations in rat optic nerves, including increased diameter, irregular axon count fluctuations (both increases and decreases), elevated astrocyte count, and a simultaneous decline in oligodendrocyte count. Additionally, it was observed that NGF-IR was predominantly at the membrane level in newborns and moderately in the cytoplasm, whereas in older ages, it was evident at both cellular and axonal levels furthermore, it was observed that GFAP-IR increased with age. However, in LM and EM examinations, axonal loss and rarefaction, accumulation of osmiophilic substances, splitting of the myelin sheath, vacuolization, axonal retraction were observed. Conclusion: In this study, it was found that one of the causes of age-related vision loss is the advanced degenerative changes in the optic nerve and it was concluded that the remaining small-diameter myelinated nerve fibers may partially compensate for the sense of vision. Our study reveals that age-related degenerative changes in the central nervous system resemble those in multiple sclerosis (MS), suggesting a potential contribution to MS pathogenesis.

Investigation of Color Vision and Contrast Sensitivity Defects in Textile Industry Workers

Background: Industrial exposure to chemicals is a significant health concern, particularly within the textile industry where workers are in regular contact with potentially harmful substances. The retina, with its photoreceptor cells responsible for color vision and contrast sensitivity, is especially susceptible to damage from such exposure. Objective: This study aims to assess the impact of chemical exposure on the color vision and contrast sensitivity of workers in the Five Star Textile Industry, drawing comparisons with previous research to better understand the occupational risks and requisite protective measures. Methods: A cross-sectional, descriptive study was conducted on 100 workers with an age range of 20-50 years, examining 200 eyes. The research took place from January to June 2023, employing the Pelli-Robson chart and D-15 test for evaluating contrast sensitivity and color vision, respectively. Data were analyzed using the Pearson Chi-Square test and SPSS version 25. Results: The study found a Pearson Chi-Square value of 31.4 for color vision in the right eye and 25.7 in the left, with a significance of 0.000 for both. Contrast sensitivity tests revealed a Pearson Chi-Square value of 44.2 for both eyes, with significance remaining at 0.000, indicating a strong correlation between chemical exposure and visual impairment. Conclusion: The findings suggest a significant relationship between prolonged chemical exposure and visual function decline among textile workers, underlining the necessity for enhanced occupational health protocols and regular vision screening.

Visual Field Dependence Persists in Age-Related Central Visual Field Loss.

To examine whether the age-related increase in visual field dependence persists in older adults with central field loss (CFL). Twenty individuals with CFL were grouped into participants with age-related binocular CFL (CFL, n = 9), age-related monocular CFL/relative scotomata (mCFL, n = 8), and CFL occurring at a young age (yCFL, n = 3). Seventeen controls were age-matched to the older CFL groups (OA) and three to the yCFL group (yOA). Participants judged the tilt direction of a rod presented at various orientations under conditions with and without a visual reference. Visual field dependence was determined as the difference in judgment bias between trials with and without the visual reference. Visual field dependence was examined between groups and relative to visual acuity and contrast sensitivity. All older groups performed similarly without the visual reference. The CFL group showed greater visual field dependence than the OA group (Mann-Whitney U test; U = 39, P = 0.045). However, there was no group difference when considering all three older groups (Kruskal-Wallis ANOVA; H(2, N = 34) = 4.31, P = 0.116). Poorer contrast sensitivity correlated with greater visual field dependence (P = 0.017; ρ = -0.43). Visual field dependence persists in older adults with CFL and seems exacerbated in those with dense binocular scotomata. This could be attributed to the sensitivity of the spared peripheral retina to orientation and motion cues. The relationship with contrast sensitivity further suggests that a decline in visual function is associated with an increase in visual field dependence beyond the effects of normal aging. These observations can guide tailored care and rehabilitation in older adults with CFL.

The effect of intraocular lens and lens eye on the treatment of macular splits in high myopia.

Macular retinoschisis in patients with high myopia is one of the main reasons for a decline in visual function and the perceived deformation of visual objects. This study aimed to investigate the therapeutic effect of cataract phacoemulsification and foldable intraocular lens implantation (FILI) combined with internal limiting membrane stripping (ILMS) in the treatment of macular retinoschisis in patients with high myopia. A total of 52 patients (55 eyes) who had been diagnosed with macular retinoschisis with high myopia between June 2019 and June 2020 were enrolled in the present study. Patients in the control group (25 eyes) received 23G vitreous surgery and macular ILMS and long-term inert gas (C3F8) filling of the vitreous cavity; patients in the research group (30 eyes) were additionally treated with cataract phacoemulsification and soft intraocular lens on the same treatment basis as the control group. The difference in average BCVA between the control and the research groups was not statistically significant before the surgery (P> 0.05) but was statistically significant 12 months after the procedure (P< 0.05). The minimum foveal thickness was significantly decreased in the two groups after the surgery compared with before the procedure (P< 0.05). Cataract phacoemulsification and FILI further improved the therapeutic effect of ILMS in the treatment of macular retinoschisis in patients with high myopia.

Технология микрохирургической реконструкции фовеа при макулярных разрывах

Macular rupture is among major vitreoretinal disorders resulting in significant visual function decline. In recent years, the use of platelet-rich autoplasma in the macular rupture surgery is considered to be promising. However, despite high rate of macular rupture closure (78–96%), the development of new technology for foveal microarchitectonics restoration and visual function improvement currently remains a pressing issue. The study was aimed to develop a new foveal reconstruction technique for macular rupture involving the use of autologous conditioned plasma. The reported study involved 9 patients (10 eyes) with idiopathic macular hole, who underwent standard three-port 27G vitrectomy involving the use of autologous conditioned plasma in accordance with the technique developed. The proposed technique makes it possible to achieve good clinical and functional surgical treatment outcome and ensures optimal and more manageable reconstruction of foveal microarchitectonics.

A microtubule stabilizer ameliorates protein pathogenesis and neurodegeneration in mouse models of repetitive traumatic brain injury.

Tau pathogenesis is a hallmark of many neurodegenerative diseases, including Alzheimer's disease (AD). Although the events leading to initial tau misfolding and subsequent tau spreading in patient brains are largely unknown, traumatic brain injury (TBI) may be a risk factor for tau-mediated neurodegeneration. Using a repetitive TBI (rTBI) paradigm, we report that rTBI induced somatic accumulation of phosphorylated and misfolded tau, as well as neurodegeneration across multiple brain areas in 7-month-old tau transgenic PS19 mice but not wild-type (WT) mice. rTBI accelerated somatic tau pathology in younger PS19 mice and WT mice only after inoculation with tau preformed fibrils and AD brain-derived pathological tau (AD-tau), respectively, suggesting that tau seeds are needed for rTBI-induced somatic tau pathology. rTBI further disrupted axonal microtubules and induced punctate tau and TAR DNA binding protein 43 (TDP-43) pathology in the optic tracts of WT mice. These changes in the optic tract were associated with a decline of visual function. Treatment with a brain-penetrant microtubule-stabilizing molecule reduced rTBI-induced tau, TDP-43 pathogenesis, and neurodegeneration in the optic tract as well as visual dysfunction. Treatment with the microtubule stabilizer also alleviated rTBI-induced tau pathology in the cortices of AD-tau-inoculated WT mice. These results indicate that rTBI facilitates abnormal microtubule organization, pathological tau formation, and neurodegeneration and suggest microtubule stabilization as a potential therapeutic avenue for TBI-induced neurodegeneration.

Impact of Monocular and Binocular Visual Function Parameters on Vision-Related Quality of Life in Glaucoma.

This study describes the impact of monocular (M/O) and binocular (B/O) visual function decline, primarily the contrast sensitivity (CS) and visual field (VF) defect severity and its location, on the subjective perception of quality of life (QoL) among the Indian glaucoma population with spared central acuity. To investigate the influence of M/O and B/O visual function parameters on vision-related QoL (VRQoL) in glaucoma with spared central visual acuity. Glaucoma subjects underwent M/O and B/O visual acuity, CS assessment, followed by the M/O perimetry from which the integrated VF was estimated (B/O summation method). VRQoL was evaluated using the Glaucoma Quality Of Life-15 (GQL-15) and Visual Function Questionnaire-Utility Index (VFQ-UI) questionnaires. The relationship between CS and VF defect (VFD) with the composite VRQoL scores was analyzed. A total of 154 glaucoma subjects with a median age of 61 (range: 24-83) years were enrolled. Subjects with severe VFD reported poor composite scores for GQL-15 and VFQ-UI when compared with unilateral and mild groups ( P < 0.001, Dunn post hoc). Both the composite scores were negatively correlated with M/O and B/O CS and VF mean deviation ( r range: -0.3 to -0.5, P < 0.001, Spearman rank correlation). B/O VFD in the inferior central zone contributed to poor GQL-15 score [odds ratio: 1.14 (95% CI: 1.10-1.29), P = 0.04] irrespective of sex, whereas females with increasing B/O VFD reported poor QoL score in VFQ-UI [odds ratio: 4.09 (95% CI: 1.77-9.43), p=0.003]. Poor GQL-15 and VFQ-UI scores were reported with increasing disease severity. B/O VFD in the inferior central region was found to contribute predominantly to the poor GQL-15 scores while both disease severity and sex influenced VFQ-UI scores.

Glaucoma-Associated CDR1 Peptide Promotes RGC Survival in Retinal Explants through Molecular Interaction with Acidic Leucine Rich Nuclear Phosphoprotein 32A (ANP32A).

Glaucoma is a complex, multifactorial optic neuropathy mainly characterized by the progressive loss of retinal ganglion cells (RGCs) and their axons, resulting in a decline of visual function. The pathogenic molecular mechanism of glaucoma is still not well understood, and therapeutic strategies specifically addressing the neurodegenerative component of this ocular disease are urgently needed. Novel immunotherapeutics might overcome this problem by targeting specific molecular structures in the retina and providing direct neuroprotection via different modes of action. Within the scope of this research, the present study showed for the first time beneficial effects of the synthetic CDR1 peptide SCTGTSSDVGGYNYVSWYQ on the viability of RGCs ex vivo in a concentration-dependent manner compared to untreated control explants (CTRL, 50 µg/mL: p < 0.05 and 100 µg/mL: p < 0.001). Thereby, this specific peptide was identified first as a potential biomarker candidate in the serum of glaucoma patients and was significantly lower expressed in systemic IgG molecules compared to healthy control subjects. Furthermore, MS-based co-immunoprecipitation experiments confirmed the specific interaction of synthetic CDR1 with retinal acidic leucine-rich nuclear phosphoprotein 32A (ANP32A; p < 0.001 and log2 fold change > 3), which is a highly expressed protein in neurological tissues with multifactorial biological functions. In silico binding prediction analysis revealed the N-terminal leucine-rich repeat (LRR) domain of ANP32A as a significant binding site for synthetic CDR1, which was previously reported as an important docking site for protein-protein interactions (PPI). In accordance with these findings, quantitative proteomic analysis of the retinae ± CDR1 treatment resulted in the identification of 25 protein markers, which were significantly differentially distributed between both experimental groups (CTRL and CDR1, p < 0.05). Particularly, acetyl-CoA biosynthesis I-related enzymes (e.g., DLAT and PDHA1), as well as cytoskeleton-regulating proteins (e.g., MSN), were highly expressed by synthetic CDR1 treatment in the retina; on the contrary, direct ANP32A-interacting proteins (e.g., NME1 and PPP2R4), as well as neurodegenerative-related markers (e.g., CEND1), were identified with significant lower abundancy in the CDR1-treated retinae compared to CTRL. Furthermore, retinal protein phosphorylation and histone acetylation were also affected by synthetic CDR1, which are both partially controlled by ANP32A. In conclusion, the synthetic CDR1 peptide provides a great translational potential for the treatment of glaucoma in the future by eliciting its neuroprotective mechanism via specific interaction with ANP32A's N terminal LRR domain.

Targeted RNAi screen identifies transcriptional mechanisms that prevent premature degeneration of adult photoreceptors.

Aging is associated with a decline in visual function and increased prevalence of ocular disease, correlating with changes in the transcriptome and epigenome of cells in the eye. Here, we sought to identify the transcriptional mechanisms that are necessary to maintain photoreceptor viability and function during aging. To do this, we performed a targeted photoreceptor-specific RNAi screen in Drosophila to identify transcriptional regulators whose knockdown results in premature, age-dependent retinal degeneration. From an initial set of 155 RNAi lines each targeting a unique gene and spanning a diverse set of transcription factors, chromatin remodelers, and histone modifiers, we identified 18 high-confidence target genes whose decreased expression in adult photoreceptors leads to premature and progressive retinal degeneration. These 18 target genes were enriched for factors involved in the regulation of transcription initiation, pausing, and elongation, suggesting that these processes are essential for maintaining the health of aging photoreceptors. To identify the genes regulated by these factors, we profiled the photoreceptor transcriptome in a subset of lines. Strikingly, two of the 18 target genes, Spt5 and domino, show similar changes in gene expression to those observed in photoreceptors with advanced age. Together, our data suggest that dysregulation of factors involved in transcription initiation and elongation plays a key role in shaping the transcriptome of aging photoreceptors. Further, our findings indicate that the age-dependent changes in gene expression not only correlate but might also contribute to an increased risk of retinal degeneration.

Swept Source Optical Coherence Tomography Angiography Findings in Birdshot Chorioretinitis: A Cross Sectional Study of 21 Patients

ABSTRACT Purpose Birdshot chorioretinitis (BSCR) is a form of posterior uveitis that is classically characterized by hypopigmented choroidal lesions outside of the major arcades. However, little is known about the extent of choroidal involvement in the macula. We aim to describe the vascular abnormalities observed at the level of the choriocapillaris (CC) in the maculae of BSCR patients, using swept source optical coherence tomography angiography (SS-OCTA). Methods A cross-sectional, observational study was conducted. Eligible patients underwent clinical examination and SS-OCTA imaging. The main outcome measures were the frequency of vascular abnormalities observed at the level of the CC on SS-OCTA and foveal choriocapillaris vascular density (CVD). Results Twenty-one patients were included, with a median age of 61.5 years. All patients had bilateral disease with a median disease duration of 6 years. All but one patient received systemic immunosuppressive drug therapy, and 19 patients had suppressed inflammation on treatment at the time of the SS-OCTA assessment. Of the 42 affected eyes, 39 (92.9%) had gradable SS-OCTA images, with a mean LogMAR visual acuity of 0.18 (Snellen equivalent 20/30). In total, 34 of 39 (87.2%) eyes had some degree of pathologic flow loss, and after controlling for patient age and disease activity, both worse VA and longer disease duration remained statistically significantly associated with reduced foveal CVD. Conclusions Our findings suggest that pathologic CC flow loss in the macula is frequently encountered and may contribute to visual function decline in patients with BSCR. Further studies with longitudinal follow-up are needed to characterize the evolution of these areas of pathologic CC flow loss over time.

Insufficient Oligodendrocyte Turnover in Optic Nerve Contributes to Age-Related Axon Loss and Visual Deficits.

Age-related decline in visual functions is a prevalent health problem among elderly people, and no effective therapies are available up-to-date. Axon degeneration and myelin loss in optic nerves (ONs) are age-dependent and become evident in middle-aged (13-18 months) and old (20-22 months) mice of either sex compared with adult mice (3-8 months), accompanied by functional deficits. Oligodendrocyte (OL) turnover is actively going on in adult ONs. However, the longitudinal change and functional significance of OL turnover in aging ONs remain largely unknown. Here, using cell-lineage labeling and tracing, we reported that oligodendrogenesis displayed an age-dependent decrease in aging ONs. To understand whether active OL turnover is required for maintaining axons and visual function, we conditionally deleted the transcription factor Olig2 in the oligodendrocyte precursor cells of young mice. Genetically dampening OL turnover by Olig2 ablation resulted in accelerated axon loss and retinal degeneration, and subsequently impaired ON signal transmission, suggesting that OL turnover is an important mechanism to sustain axon survival and visual function. To test whether enhancing oligodendrogenesis can prevent age-related visual deficits, 12-month-old mice were treated with clemastine, a pro-myelination drug, or induced deletion of the muscarinic receptor 1 in oligodendrocyte precursor cells. The clemastine treatment or muscarinic receptor 1 deletion significantly increased new OL generation in the aged ONs and consequently preserved visual function and retinal integrity. Together, our data indicate that dynamic OL turnover in ONs is required for axon survival and visual function, and enhancing new OL generation represents a potential approach to reversing age-related declines of visual function.SIGNIFICANCE STATEMENT Oligodendrocyte (OL) turnover has been reported in adult optic nerves (ONs), but the longitudinal change and functional significance of OL turnover during aging remain largely unknown. Using cell-lineage tracing and oligodendroglia-specific manipulation, this study reported that OL generation was active in adult ONs and the efficiency decreased in an age-dependent manner. Genetically dampening OL generation by Olig2 ablation resulted in significant axon loss and retinal degeneration, along with delayed visual signal transmission. Conversely, pro-myelination approaches significantly increased new myelin generation in aging ONs, and consequently preserved retinal integrity and visual function. Our findings indicate that promoting OL generation might be a promising strategy to preserve visual function from age-related decline.

Каротиноиды в терапии возрастной макулярной дегенерации: система доставки имеет значение

Age-related macular degeneration (AMD) is one of the leading causes of low vision and blindness worldwide for people over age 60. By 2040, the number of people living with macular degeneration is expected to reach 288 million due to the exponential acceleration of population aging. A decline in visual functions caused by AMD has a significant economic impact in all countries. Besides aging, there are other multiple heterogenic risk factors associated with AMD: gender, environmental condition, lifestyle, genetic characteristics, chronic inflammatory processes in the human body, level of education, etc. It is important for the ophthalmologist to be aware of modifiable risk factors and thus to collect a comprehensive medical history, interact with patients using motivational interviewing and to involve promptly other healthcare specialists into the patient management strategy. Etiopathogenesis of AMD is still not entirely understood. However, it is known that the major pathways include age-related alterations of retinal pigment epithelium (RPE) cells, oxidative stress, dysregulated lipid metabolism, inflammation, hemodynamic changes, and neovascularization. Carotenoids lutein and zeaxanthin are natural compounds with a proven efficacy in reducing AMD progression, which have been demonstrated to act as medications for patients with early AMD stages. The micro- encapsulated formula offers such an advantage as gradual and controlled release of active substances. Keywords: age-related macular degeneration, risk factors, etiopathogenesis, carotenoids, lutein, zeaxanthin, microcapsules. For citation: Maksimov M.L., Oganezova J.G., Kanner I.D., Voznesenskaya A.A. Carotenoids in the treatment of age-related macular degeneration: a drug delivery system does matter. Russian Journal of Clinical Ophthalmology. 2023;23(1):60–65 (in Russ.). DOI: 10.32364/2311-7729-2023-23-1-60-65.

Evaluation of Anti-Infectious Activity of Bioconjugates Based on Quantum Dots CdTe / Cd MPA 710 and Levofloxacin against Staphylococcal Corneal Infection. Experimental Research

Infectious keratitis is one of the leading causes of persistent decline in visual function and monocular blindness in both developed and developing countries. The combination of factors in the prevalence of eye infectious and inflammatory diseases, antibiotic resistance, and internal mutations of the pathogens themselves exacerbate the need to search for highly effective alternatives in the fight against eye infectious diseases. Of particular interest are the prospects for the use of fluorescent semiconductor nanocrystals, called quantum dots, in the treatment of resistant infectious inflammatory diseases. The objective of the study was to assess the anti-infectious activity of bioconjugates based on CdTe / Cd MPA 710 quantum dots and levofloxacin against staphylococcal corneal infection using the example induced infectious keratitis in laboratory animals. As the object of the study, 6 male (6 eyes) New Zealand rabbits were studied, which underwent induction of bacterial keratitis by introducing a hospital strain of S. Aureus into the structure of the cornea. The following were used as antimicrobial agents: a solution of levofloxacin 5 ml for epibulbar use and a bioconjugate based on CT CdTe / Cd MPA 710 and levofloxacin.

Vision With Retrodots and Factors for Declining Visual Function.

We investigated decline in the visual function of eyes with retrodots (RDs)-a subtype of cataract. This study included 57 eyes with RD opacity only (mean age 72.3 ± 5.2 years) and 34 eyes with transparent lenses (mean age 71.4 ± 3.7 years). A physician diagnosed lens opacity. Using the Kanazawa Medical University Classification and Grading System, the eyes were classified into the RD-1 (37 eyes, RDs <25% of the 3-mm pupil area) and RD-2 (20 eyes, RDs ≥25% of the 3-mm pupil area) groups. Corrected distance visual acuity, contrast visual acuity, ocular refractive power, lens power, straylight, and backward light-scattering intensity and their relationship with visual function decline and optical characteristics of the eyeball were evaluated. Corrected distance visual acuity was significantly lower in the RD eyes than in controls. Contrast visual acuity decreased significantly in the RD-2 eyes in all environments and in the RD-1 eyes in the evening (EVE) and EVE + glare. Straylight was significantly higher in the RD-2 eyes than in the controls and RD-1 eyes but not different between the RD-1 eyes and controls. The RD-2 eyes were significantly more myopic than the controls and RD-1 eyes. When the opacity of RD eyes is ≥25%, the visual acuity and contrast visual acuity decrease and straylight increases. Furthermore, myopia occurs as the refractive power of the lens increases. Moreover, visual function decline may be due to an increase in the straylight value, which is necessary for determining surgical indications.

Optic perineuritis.

This review paper aims at discussing pathogenesis, etiology, clinical features, management, and prognosis of OPN. Optic perineuritis (OPN) is an inflammatory process primarily involving the optic nerve sheath. Clinically, OPN usually presents with unilateral, gradual decline of visual function, eye pain, and/or pain on eye movements, disc edema and various features of optic nerve dysfunction, including visual field defects. It can mimic typical optic neuritis. In most cases of OPN, the disease is isolated with no specific etiology being identified, however, it can also occur secondary to a wide range of underlying systemic diseases. OPN is clinically diagnosed and radiologically confirmed based on the finding of circumferential perineural enhancement of the optic nerve sheath on magnetic resonance imaging (MRI). Unlike optic nerve, OPN is not typically self-limited without treatment. High-dose oral corticosteroids are the mainstay of treatment in OPN. The initiation of therapy usually causes rapid and dramatic improvement in signs and symptoms. In general, OPN usually has a relatively good visual prognosis, which is influenced by delays between the onset of visual loss and the initiation of steroid therapy as well as the presence of underlying systemic diseases.

Mental arithmetic task classification with convolutional neural network based on spectral-temporal features from EEG.

In recent years, neuroscientists have been interested to the development of brain-computer interface (BCI) devices. Patients with motor disorders may benefit from BCIs as a means of communication and for the restoration of motor functions. Electroencephalography (EEG) is one of most used for evaluating the neuronal activity. In many computer vision applications, deep neural networks (DNN) show significant advantages. Towards to ultimate usage of DNN, we present here a shallow neural network that uses mainly two convolutional neural network (CNN) layers, with relatively few parameters and fast to learn spectral-temporal features from EEG. We compared this models to three other neural network models with different depths applied to a mental arithmetic task using eye-closed state adapted for patients suffering from motor disorders and a decline in visual functions. Experimental results showed that the shallow CNN model outperformed all the other models and achieved the highest classification accuracy of 90.68%. It's also more robust to deal with cross-subject classification issues: only 3% standard deviation of accuracy instead of 15.6% from conventional method.

Study on the mechanism of visual aging in cats’ primary visual cortex based on BDNF-TrkB signal pathway

To explore the expression of brain-derived neurotrophic factor (BDNF) and specific receptor tyrosine kinase receptor B (TrkB) in the primary visual cortex of young and old cats, especially to reveal the age-related differences in the mediating mechanism of BDNF-TrkB signaling pathway in cats’ visual cortex and their possible effects on synaptic plasticity, Nissl staining was used to display neurons in each layer of cats’ primary visual cortex, and immunohistochemical ABC method was used to label BDNF and TrkB immunopositive cells in each layer of cats’ primary visual cortex. The BDNF and TrkB receptor immunoreactive neurons and non-neurons were observed and photographed. Their density and immunoreactive intensity were measured. Results showed that BDNF and TrkB were widely expressed in all layers of visual cortex in young and old cats. Compared with the young group, the density and intensity of BDNF and TrkB positive cells in each layer of primary visual cortex in the old group decreased significantly (P < 0.01). The findings indicate that the expression levels of BDNF and TrkB in the primary visual cortex of cats decrease with age, suggesting that the change of BDNF-TrkB signal pathway caused by the weakening of brain-derived neurotrophic factor activity may be one of the important reasons for the decline of visual function.