Publications

2014

Gupta M, Leskov I, Kruger J, Cestari D. Intermittent Horner syndrome in a pediatric patient. J Neuroophthalmol. 2014;34(2):149–50.
Intermittent Horner syndrome is uncommon in both the adult and pediatric population. We describe a case of a pediatric patient with an intermittent Horner syndrome. Infrared photography and videography were used to help establish the diagnosis.
Hansen R, Tavormina J, Moskowitz A, Fulton A. Effect of retinopathy of prematurity on scotopic spatial summation. Invest Ophthalmol Vis Sci. 2014;55(5):3311–3.
PURPOSE: To evaluate scotopic retinal organization in retinopathy of prematurity (ROP) through a study of spatial summation. METHODS: Thresholds for a range of stimulus diameters (0.4°-10°) were measured using a two alternative, spatial, forced choice psychophysical procedure. The critical diameter (DCRIT) for complete summation was estimated in subjects with a history of severe ROP (N = 7) and mild ROP (N = 17). Subjects who were born preterm and never had ROP (N = 16) and term-born subjects (N = 7) were also tested. The subjects ranged in age from 9 to 17 (median 13.5) years. RESULTS: Critical diameter for complete spatial summation was significantly larger in ROP subjects than in subjects who never had ROP and in term-born control subjects. Critical diameter varied significantly with severity of ROP. CONCLUSIONS: The larger DCRIT values in ROP are consistent with altered organization of the post receptor retina. This may offer the ROP retina a strategy for achieving noise reduction and good dark-adapted visual sensitivity.
Harrison W, Bex P. Integrating retinotopic features in spatiotopic coordinates. J Neurosci. 2014;34(21):7351–60.
The receptive fields of early visual neurons are anchored in retinotopic coordinates (Hubel and Wiesel, 1962). Eye movements shift these receptive fields and therefore require that different populations of neurons encode an object's constituent features across saccades. Whether feature groupings are preserved across successive fixations or processing starts anew with each fixation has been hotly debated (Melcher and Morrone, 2003; Melcher, 2005, 2010; Knapen et al., 2009; Cavanagh et al., 2010a,b; Morris et al., 2010). Here we show that feature integration initially occurs within retinotopic coordinates, but is then conserved within a spatiotopic coordinate frame independent of where the features fall on the retinas. With human observers, we first found that the relative timing of visual features plays a critical role in determining the spatial area over which features are grouped. We exploited this temporal dependence of feature integration to show that features co-occurring within 45 ms remain grouped across eye movements. Our results thus challenge purely feedforward models of feature integration (Pelli, 2008; Freeman and Simoncelli, 2011) that begin de novo after every eye movement, and implicate the involvement of brain areas beyond early visual cortex. The strong temporal dependence we quantify and its link with trans-saccadic object perception instead suggest that feature integration depends, at least in part, on feedback from higher brain areas (Mumford, 1992; Rao and Ballard, 1999; Di Lollo et al., 2000; Moore and Armstrong, 2003; Stanford et al., 2010).
Heidary G, Calderwood L, Cox G, Robson C, Teot L, Mullon J, Anselm I. Optic atrophy and a Leigh-like syndrome due to mutations in the c12orf65 gene: report of a novel mutation and review of the literature. J Neuroophthalmol. 2014;34(1):39–43.
Combined oxidative phosphorylation deficiency type 7 (COXPD7) is a rare disorder of mitochondrial metabolism that results in optic atrophy and Leigh syndrome-like disease. We describe 2 siblings with compound heterozygous mutations in the recently identified C12orf65 gene who presented with optic atrophy and mild developmental delays and subsequently developed bilateral, symmetric lesions in the brainstem reminiscent of Leigh syndrome. Repeat neuroimaging demonstrated reversibility of the findings in 1 sibling and persistent metabolic stroke in the other. This article highlights the phenotypic manifestations from a novel mutation in the C12orf65 gene and reviews the clinical presentation of the 5 other individuals reported to date who carry mutations in this gene.
Hong J, Liu Z, Hua J, Wei A, Xue F, Yang Y, Sun X, Xu J. Evaluation of age-related changes in noninvasive tear breakup time. Optom Vis Sci. 2014;91(2):150–5.
PURPOSE: To establish normal noninvasive tear film breakup time (NI-BUT) values in the Chinese population and investigate age-related changes in NI-BUT using a newly developed Keratograph. METHODS: Forty normal volunteers with a mean age of 32.8 ± 16.7 years were recruited for this study. Clinical and demographic data, including age, gender, fluorescein tear film breakup time (FBUT), and Schirmer I test values were collected from the subjects. Noninvasive tear film breakup time was measured using a new method based on a corneal topographer equipped with a modified scan software. The correlations between the NI-BUT, age, and gender were determined. RESULTS: In total, a significant difference between the NI-BUT and the FBUT was found (4.9 ± 2.4 seconds vs. 9.0 ± 3.0 seconds; p < 0.001). No statistically significant difference in the NI-BUT was observed between the male and female subjects (5.5 ± 2.0 seconds vs. 4.5 ± 2.5 seconds; p = 0.137). In addition, no significant correlation was detected between the NI-BUT and age (0.143, p = 0.321). CONCLUSIONS: The NI-BUT values found in this study are much lower than those of previous reports. Our results show no significant differences in tear film stability with age. The tear physiology of the Chinese population may not be the same as in Western populations.
Hou Y, Lin H, Zhu L, Liu Z, Hu F, Shi J, Yang T, Shi X, Guo H, Tan X, Zhang L, Wang Q, Li Z, Zhao Y. The inhibitory effect of IFN-γ on protease HTRA1 expression in rheumatoid arthritis. J Immunol. 2014;193(1):130–8.
The high temperature requirement A1 (HTRA1) is a potent protease involved in many diseases, including rheumatoid arthritis (RA). However, the regulatory mechanisms that control HTRA1 expression need to be determined. In this study, we demonstrated that IFN-γ significantly inhibited the basal and LPS-induced HTRA1 expression in fibroblasts and macrophages, which are two major cells for HTRA1 production in RA. Importantly, the inhibitory effect of IFN-γ on HTRA1 expression was evidenced in collagen-induced arthritis (CIA) mouse models and in human RA synovial cells. In parallel with the enhanced CIA incidence and pathological changes in IFN-γ-deficient mice, HTRA1 expression in the joint tissues was also increased as determined by real-time PCR and Western blots. IFN-γ deficiency increased the incidence of CIA and the pathological severity in mice. Neutralization of HTRA1 by Ab significantly reversed the enhanced CIA frequency and severity in IFN-γ-deficient mice. Mechanistically, IFN-γ negatively controls HTRA1 expression through activation of p38 MAPK/STAT1 pathway. Dual luciferase reporter assay and chromatin immunoprecipitation analysis showed that STAT1 could directly bind to HTRA1 promoter after IFN-γ stimulation. This study offers new insights into the molecular regulation of HTRA1 expression and its role in RA pathogenesis, which may have significant impact on clinical therapy for RA and possibly other HTRA1-related diseases, including osteoarthritis, age-related macular degeneration, and cancer.
It is known that inoculation of antigen into the anterior chamber (a.c.) of a mouse eye induces a.c.-associated immune deviation (ACAID), which is mediated in part by antigen-specific local and peripheral tolerance to the inciting antigen. ACAID can also be induced in vivo by intravenous (i.v.) inoculation of ex-vivo-generated tolerogenic antigen-presenting cells (TolAPC). The purpose of this study was to test if in-vitro-generated retinal antigen-pulsed TolAPC suppressed established experimental autoimmune uveitis (EAU). Retinal antigen-pulsed TolAPC were injected i.v. into mice 7 days post-induction of EAU. We observed that retinal antigen-pulsed TolAPC suppressed the incidence and severity of the clinical expression of EAU and reduced the expression of associated inflammatory cytokines. Moreover, extract of whole retina efficiently replaced interphotoreceptor retinoid-binding protein (IRBP) in the preparation of TolAPC used to induce tolerance in EAU mice. Finally, the suppression of EAU could be transferred to a new set of EAU mice with CD8⁺ but not with CD4⁺ regulatory T cells (T(reg)). Retinal antigen-pulsed TolAPC suppressed ongoing EAU by inducing CD8⁺ T(reg) cells that, in turn, suppressed the effector activity of the IRBP-specific T cells and altered the clinical symptoms of autoimmune inflammation in the eye. The ability to use retinal extract for the antigen raises the possibility that retinal extract could be used to produce autologous TolAPC and then used as therapy in human uveitis.
Huang L, Sun X, Luo G, Liu S, Liu R, Mansouri B, Wong VWL, Wen W, Liu H, Wang AH. Interocular Shift of Visual Attention Enhances Stereopsis and Visual Acuities of Anisometropic Amblyopes beyond the Critical Period of Visual Development: A Novel Approach. J Ophthalmol. 2014;2014:615213.
Aims. Increasing evidence shows that imbalanced suppressive drive prior to binocular combination may be the key factor in amblyopia. We described a novel binocular approach, interocular shift of visual attention (ISVA), for treatment of amblyopia in adult patients. Methods. Visual stimuli were presented anaglyphically on a computer screen. A square target resembling Landolt C had 2 openings, one in red and one in cyan color. Through blue-red goggles, each eye could only see one of the two openings. The patient was required to report the location of the opening presented to the amblyopic eye. It started at an opening size of 800 sec of arc, went up and down in 160 sec of arc step, and stopped when reaching the 5th reversals. Ten patients with anisometropic amblyopia older than age 14 (average age: 26.7) were recruited and received ISVA treatment for 6 weeks, with 2 training sessions per day. Results. Both Titmus stereopsis (z = -2.809, P = 0.005) and Random-dot stereopsis (z = -2.317, P = 0.018) were significantly improved. Average improvement in best corrected visual acuity (BCVA) was 0.74 line (t = 5.842, P < 0.001). Conclusions. The ISVA treatment may be effective in treating amblyopia and restoring stereoscopic function.
PURPOSE: The purpose of this study is to evaluate the functional and morphological changes in subretinal xenografts of human retinal progenitor cells (hRPCs) in B6 mice treated with Cyclosporin A (CsA; 210 mg/l in drinking water). METHODS: The hRPCs from human fetal eyes were isolated and expanded for transplantation. These cells, with green fluorescent protein (GFP) at 11 passages, were transplanted into the subretinal space in B6 mice. A combination of invasive and noninvasive approaches was used to analyze the structural and functional consequences of the subretinal injection of the hRPCs. The process of change was monitored using spectral domain optical coherence tomography (SDOCT), histology, and electroretinography (ERG) at 3 days, 1 week, and 3 weeks after transplantation. Cell counts were used to evaluate the survival rate with a confocal microscope. ERGs were performed to evaluate the physiologic changes, and the structural changes were evaluated using SDOCT and histological examination. RESULTS: The results of the histological examination showed that the hRPCs gained a better survival rate in the mice treated with CsA. The SDOCT showed that the bleb size of the retinal detachment was significantly decreased, and the retinal reattachment was nearly complete by 3 weeks. The ERG response amplitudes in the CsA group were less decreased after the injection, when compared with the control group, in the dark-adapted and light-adapted conditions. However, the cone-mediated function in both groups was less affected by the transplantation after 3 weeks than the rod-mediated function. CONCLUSIONS: Although significant functional and structural recovery was observed after the subretinal injection of the hRPCs, the effectiveness of CsA in xenotransplantation may be a novel and potential approach for increasing retinal progenitor cell survival.
Watching 3D content using a stereoscopic display may cause various discomforting symptoms, including eye strain, blurred vision, double vision, and motion sickness. Numerous studies have reported motion-sickness-like symptoms during stereoscopic viewing, but no causal linkage between specific aspects of the presentation and the induced discomfort has been explicitly proposed. Here, we describe several causes, in which stereoscopic capture, display, and viewing differ from natural viewing resulting in static and, importantly, dynamic distortions that conflict with the expected stability and rigidity of the real world. This analysis provides a basis for suggested changes to display systems that may alleviate the symptoms, and suggestions for future studies to determine the relative contribution of the various effects to the unpleasant symptoms.