Eye Levels Research Articles

GM-CSF mediates development of eosinophil-dominant autoimmune uveitis in the absence of both IFN-γ and IL-17A

Abstract Autoimmune uveitis is a group of blinding diseases triggered by activated retina-specific T cells. Studies in uveitis patients and experiments in animal models of experimental autoimmune uveitis (EAU) support the notion that Th1 and Th17 cells are both pathogenic effectors and each can elicit ocular autoimmunity independently of the other. Since absence of IFN-γ or IL-17A individually failed to abolish pathology of EAU, we examined EAU development in the absence of both cytokines. Ifng−/−Il17a−/− mice were fully susceptible to EAU and displayed eosinophil-dominant ocular infiltrates, as opposed to mononuclear infiltrates in WT mice. EAU was ameliorated in double-deficient mice when eosinophils were genetically absent or their migration was blocked, supporting a pathogenic role of eosinophils in the absence of both IFN-γ and IL-17A. In Ifng−/−Il17a−/− mice immunized for EAU, ocular infiltrates contained increased GM-CSF-producing CD4 T cells, and supernatants of antigen-recalled splenocytes contained enhanced levels of GM-CSF that contributed to activation and migration of eosinophils in vitro. Systemic or local blockade of GM-CSF ameliorated EAU in Ifng−/−Il17a−/− mice. Neutralization of GM-CSF during the induction phase of EAU decreased eosinophil infiltration to the eye and eosinophil peroxidase levels in the eye and in the serum. These results support the interpretation that, in the concurrent absence of IFN-γ and IL-17A, GM-CSF takes on a major role as a pathogenic effector cytokine and induces an eosinophil-dominant pathology. This may impact therapeutic strategies aiming to target IFN-γ and IL-17A in autoimmune uveitis.

Expression of Melatonin and Dopamine D3 Receptor Heteromers in Eye Ciliary Body Epithelial Cells and Negative Correlation with Ocular Hypertension.

Background: Experiments in the late nineties showed an inverse relationship in the eye levels of melatonin and dopamine, thereby constituting an example of eye parameters that are prone to circadian variations. The underlying mechanisms are not known but these relevant molecules act via specific cell surface dopamine and melatonin receptors. This study investigated whether these receptors formed heteromers whose function impact on eye physiology. We performed biophysical assays to identify interactions in heterologous systems. Particular heteromer functionality was detected using Gi coupling, MAPK activation, and label-free assays. The expression of the heteroreceptor complexes was assessed using proximity ligation assays in cells producing the aqueous humor and human eye samples. Dopamine D3 receptors (D3Rs) were identified in eye ciliary body epithelial cells. We discovered heteromers formed by D3R and either MT1 (MT1R) or MT2 (MT2R) melatonin receptors. Heteromerization led to the blockade of D3R-Gi coupling and regulation of signaling to the MAPK pathway. Heteromer expression was negatively correlated with intraocular hypertension. Conclusions: Heteromers likely mediate melatonin and dopamine actions in structures regulating intraocular pressure. Significant expression of D3R–MT1R and D3R–MT1R was associated with normotensive conditions, whereas expression diminished in a cell model of hypertension. A clear trend of expression reduction was observed in samples from glaucoma cases. The trend was marked but no statistical analysis was possible as the number of available eyes was 2.

Incidence of and Risk Factors Associated With Age-Related Macular Degeneration

While the prevalence of age-related macular degeneration (AMD) differs according to continents and races/ethnicities, its incidence in the European continent has been scarcely documented. To describe the incidence and associated risk factors of AMD in elderly French individuals. This population-based cohort study of 963 residents of Bordeaux, France, who were 73 years or older at baseline and participated in the Antioxydants, Lipides Essentiels, Nutrition et Maladies Oculaires (ALIENOR) Study between October 2, 2006, and December 21, 2012. Of 829 participants at risk for incident AMD, 659 (79.5%) were observed for a mean (SD) duration of 3.8 (1.1) years. Data were analyzed from August 2016 to March 2017. Age-related macular degeneration was graded from retinal photographs and spectral-domain optical coherence tomography into 5 exclusive stages: no AMD, early AMD1, early AMD2, late atrophic AMD, and late neovascular AMD. Of the 659 eligible participants, 413 (62.7%) were women, and the mean (SD; range) age was 79.7 (4.4; 73-94) years. A total of 120 incident cases of early AMD and 45 incident cases of advanced AMD were recorded. Incidence rates of early and advanced AMD were 79.9 (95% CI, 66.8-95.5) per 1000 person-years and 18.6 (95% CI, 13.9-24.9) per 1000 person-years, respectively, corresponding to 5-year risks of 32.9% and 8.9%. Incidence of advanced AMD per 1000 eye-years was 1.5 in eyes without any AMD at baseline, 42.4 in those with early AMD1, and 85.1 in those with early AMD2. In multivariate analysis without correction for multiple testing, progression from early to advanced AMD was associated with AMD grade in the fellow eye (hazard ratio [HR] according to grade, 13.0 [95% CI, 2.8-61.2] to 22.5 [95% CI, 2.6-195.9]), having smoked at least 20 pack-years (calculated as number of smoking years × mean number of cigarettes per day / 20; HR, 3.0; 95% CI, 1.4-6.5), and complement factor H (CFH) Y402H genotype (CC genotype: HR, 2.3; 95% CI, 1.0-5.3; TC genotype: HR, 1.5; 95% CI, 0.6-3.7). Incidence of early AMD was associated with early AMD in the fellow eye (early AMD1: HR, 2.6; 95% CI, 1.6-4.2; early AMD2: HR, 5.6; 95% CI, 3.3-9.4) and high plasma high-density lipoprotein cholesterol levels (HR, 1.2; 95% CI, 1.0-1.4). In this cohort, AMD incidence rates were similar to those observed in other European populations. This study suggests a high risk for incident early AMD in individuals with high plasma high-density lipoprotein cholesterol levels while confirming the high risk for progression from early to advanced AMD in heavy smokers and carriers of CFH Y402H at-risk genotypes.

A multi-measure approach for connecting cognitive workload and automation

Abstract Eye behavior metrics, time of run, and subjective survey results were assessed during human-computer interaction with high, low, and intermediate system autonomy levels. The results of this study are provided as a contribution to knowledge on the relationship between cognitive workload physiology and automation. Research suggests that changes in eye behavior metrics are related to changes in cognitive workload. Few studies have investigated the relationship between eye behavior metrics physiology measures and levels of automation. A within-subjects experiment involving 18 participants who played an open-source real-time strategy game was conducted. Three different versions of the game were developed, each with a unique static autonomy level designed from Sheridan and Verplank's 10 levels of autonomy (levels 2, 4, and 9). NASA-TLX subject survey ratings, time to complete run, and visual fixation rate were found to be significantly different among automation levels. These findings suggest that assessing visual physiology may be a promising indicator for evaluating cognitive workload when interacting with static autonomy levels. This efforts takes us one step closer to using visual physiology as a useful method for evaluating operator workload in almost real-time. Relevance to industry Potential applications of this research include development of software that integrates adaptive automation to improve human-computer task performance for high cognitive workload tasks (Air Traffic Control, aircraft piloting, process control, information analyst, etc.).

Efficacy and Safety of Carbomer-Based Lipid-Containing Artificial Tear Formulations in Patients With Dry Eye Syndrome.

To evaluate the efficacy and safety profile of carbomer-based lipid-containing artificial tear formulations (CBLAT) in patients with dry eye syndrome. A multicenter parallel-group study was conducted in 412 patients with dry eye syndrome. Of these patients, 221 switched from using artificial tears to CBLAT (switching group) and 191 added CBLAT to their current treatment (add-on group). Ocular symptom scores, ocular staining grades, tear film breakup time (tBUT), Schirmer I test value, and Korean dry eye level (as defined by the Korean Corneal Disease Study Group guidelines) were evaluated at baseline and after 4 weeks of treatment. After 4 weeks of treatment, ocular surface staining grade, tBUT, Schirmer I value, ocular irritation symptom scores, and the positive rate of visual symptom improved significantly in both groups. Mean reductions in ocular surface staining grades (-0.8 ± 0.9) and ocular irritation symptom scores (-0.8 ± 0.8) in the add-on group were significantly higher than those (-0.5 ± 0.8 and -0.6 ± 0.8) in the switching group (P < 0.01 and P < 0.05). The positive rate of visual symptoms (44.2%) in the add-on group was significantly higher than that (26.4%) in the switching group (P < 0.01). The decrease of Korean dry eye level was 30.1% in the switching group and 51.6% in the add-on group. More patients in the add-on group had decreased dry eye levels than those in the switching group (P < 0.0001). CBLAT improves ocular surface staining grades, tBUT, Schirmer I values, and ocular symptoms in patients with dry eye syndrome.

Oxidative stress impact on growth hormone secretion in the eye.

AimTo evaluate the influence of oxidative stress on extrapituitary growth hormone (GH) secretion in the eye and to analyze the interdependence between eye and serum GH levels under normal and hypoxic conditions.MethodsPars plana vitrectomy (PPV) was performed in 32 patients with developed proliferative diabetic retinopathy (PDR) and 49 non-diabetic controls, both of whom required this procedure as part of their regular treatment in the period from April 2013 to December 2014. During PPV, vitreous samples were taken and blood was simultaneously collected from the cubital vein. GH levels in serum and vitreous samples were measured by electrochemical luminescence assay. Oxidative stress was measured by enzyme-linked immunosorbent assay of advanced oxidation protein products (AOPP) and lipid hydroperoxide (LPO) in serum and vitreous.ResultsSerum AOPP levels were significantly higher than vitreous levels in both groups (P < 0.001 for each group) and LPO levels were significantly higher only in PDR group (P < 0.001). There was a significant positive correlation between serum and vitreous LPO levels in PDR group (r = 0.909; P < 0.001). Serum GH levels were significantly higher than vitreous levels in both groups (P < 0.001 for each group). Serum GH levels were significantly higher in PDR group than in controls (P = 0.012). Vitreous GH values were slightly higher in PDR group, but the difference was not significant.ConclusionOur study confirms that GH production in the eye is autonomous and independent of oxidative stress or pituitary GH influence.

Evaluating approaches to measuring ocular pain in bovine calves with corneal scarification and infectious bovine keratoconjunctivitis–associated corneal ulcerations1

Infectious bovine keratoconjunctivitis (IBK) is a common ocular disease in cattle, associated with a 6.8 to 13.6 kg decrease in weaning weight. Antibiotic therapy is available but it is unclear if pain mitigation as an adjunct therapy would reduce the weight loss associated with IBK. Before assessing the impact of pain mitigation therapies, it is first necessary to validate approaches to qualifying ocular pain. The objective of this study was to evaluate approaches to qualifying ocular pain in bovine calves (Bos taurus) with IBK. Our a priori assumption was that scarification or corneal ulcerations consistent with IBK are painful compared to normal eyes. To quantify this difference in pain, we assessed 4 tools: pressure algometry-mechanical nociceptive threshold (PA-MNT), corneal touch thresholds (CTT) obtained with the use of a Cochet-Bonnet aesthesiometer, and assessment for the presence of blepharospasm and photophobia as metrics for pain. Using a 1-eye randomized controlled challenge trial, 31 calves with healthy eyes were randomly allocated to treatment groups, and then a left or right eye was randomly assigned for corneal scarification and inoculation with Moraxella bovoculi or Moraxella bovis. A repeated measures analysis of variance was used for PA-MNT, with significance set at P < 0.05. A log (base 10) transformation was used to stabilize the variance, and Tukey's t tests were used to test differences between assessment days for each landmark. Calves had statistically significantly lower PA-MNT scores (which indicates more pain) the day after scarification relative to baseline measurements (4 d before scarification). For example, at 1 landmark the median PA-MNT (kg/force) prescarification was 4.82 (95% confidence interval [CI]: 3.92-5.93) and 3.43 (95% CI: 2.79-4.22) postscarification. These data suggest PA-MNT may be a tool for quantifying ocular pain in calves. No differences (P < 0.1) in PA-MNT scores between scarified and not-scarified eyes were detected for any landmark on any day. This result suggests that the pain response occurs over the entire face, not just the affected eye. Corneal ulcerations consistent with IBK were not associated with statistically significant differences in PA-MNT or CTT at eye or calf levels. Not surprisingly, scarified eyes were more likely to exhibit blepharospasm and photophobia compared to healthy eyes. Due to blepharospasm, the use of the Cochet-Bonnet to evaluate corneal sensitivity by CTT was of limited value.

Current Practice Pattern for Dry Eye Patients in South Korea: A Multicenter Study

PurposeTo assess current practice patterns for dry eye patients in South Korea and to evaluate the preference according to the ages and clinic types of physicians.MethodsDry eye patients (n = 1,612) were enrolled in this multicenter cross-sectional, observational study. The severity level of dry eye patients was classified based on the Korean guidelines for dry eye treatment. The medical records of the enrolled dry eye patients were evaluated, and the practice styles and the preferences were analyzed according to the ages and clinic types of physicians.ResultsOf all patients, dry eye level 1 was most common (47.5%), followed by level 2 (33.5%), level 3 (9.1%), and level 4 (1.1%). Topical anti-inflammatory agents were used in 70.7% of patients with dry eye level 2 and in 80.6% of patients at levels 3 and 4. Topical anti-inflammatory agents were also used in 48.7% of patients with dry eye level 1. Preservative-free artificial tears were preferred at all dry eye levels. The use of topical anti-inflammatory agents did not differ with investigator ages, but older physicians preferred preserved artificial tears more than younger ones. Physicians at referral hospitals also tended to use topical anti-inflammatory agents and preservative-free artificial tears earlier, beginning at dry eye level 1, than those who worked at private eye clinics.ConclusionsTopical anti-inflammatory agents were commonly prescribed for the treatment of dry eye patients in South Korea, even from dry eye level 1. Preservative-free artificial tears were preferred at all dry eye levels. Practice styles differed somewhat depending on the ages and clinic types of physicians.

Reduction of Operator Radiation Dose by an Extended Lower Body Shield

PurposeTo quantify the reduction in operator exposure to scatter radiation by using an extension component in addition to a commonly used lower body radiation shield attached to an interventional radiology procedure table. Materials and MethodsAn anthropomorphic pelvis phantom was exposed to fluoroscopy at varying C-arm angles to simulate a standard interventional procedure. A MAVIG UT60 lower body shield (MAVIG, Munich, Germany) (48 cm × 78 cm, 0.5 mm lead equivalent), with an attachable extension component (48 cm × 36 cm), was suspended from the edge of the table adjacent to the pelvic phantom. Using a handheld Geiger counter, scatter radiation exposure rates were measured at the level of an operator’s eye, chest, waist, and knee, with various C-arm angles both with and without the attachable extension component. Mean exposure rates for each experimental setup were calculated and compared. ResultsOverall, scatter radiation exposures were lower with the addition of the extension component, with the largest reductions (> 80%) measured at the operator’s waist and knee levels, for all C-arm angles. The highest reduction in scatter radiation exposure was measured at knee level, at 0 degrees left posterior oblique projection, where the use of the lower body shield extension component reduced the exposure rate from 4.80 mR/h to 0.44 mR/h (90.8% reduction, P < .001). Reductions in scatter radiation were less at eye and chest levels. ConclusionsThe use of the additional extension component to the lower body radiation shield can result in large (> 80%) reductions in operator scatter radiation exposure, particularly to the lower body.

Ocular Demodicosis as a Risk Factor of Pterygium Recurrence

To evaluate ocular demodicosis as a potential risk factor in pterygium recurrence. Cross-sectional study to correlate clinical findings with laboratory data. We retrospectively reviewed 94 patients (43 with primary and 51 with recurrent pterygia), among whom 68 patients received surgical correction, and prospectively enrolled another 23 pterygium patients and 14 nonpterygium controls for measuring the tear level of interleukin (IL)-17. All patients had microscopically confirmed ocular demodicosis. Statistical correlations were analyzed among age, sex, aqueous tear deficiency, dry eye, ocular demodicosis, follow-up period, surgical outcome, and tear levels of IL-17 measured by enzyme-linked immunosorbent assay. Correlation between ocular demodicosis or IL-17 levels and pterygium recurrence. Among 94 patients, ocular demodicosis was more prevalent in patients with recurrent pterygium than those with primary pterygium (P = 0.015). During follow-up of 16.5 ± 11.5 months, 68 postsurgical patients developed 7 corneal recurrences, which constituted 7.4% of primary and 12.2% of recurrent pterygium (P = 0.820). They also developed 8 conjunctival recurrences. Kaplan-Meier survival analysis showed combined (P = 0.000), corneal (P = 0.044), and conjunctival (P = 0.002) recurrence was significantly higher among patients with demodicosis than those without. Conjunctival recurrence occurred within 6 months in eyes without demodicosis but extended beyond 6 months in eyes with demodicosis. In 34 postsurgical patients with demodicosis, the mite count of 14 patients with recurrence was significantly higher than that of 20 without (P = 0.005). The IL-17 level was significantly higher in patients with either pterygium or demodicosis than controls (P = 0.049 and 0.040, respectively), and the IL-17 level was further elevated in patients with both pterygium and demodicosis (all P<0.05). Ocular demodicosis is a risk factor for pterygium recurrence, especially for conjunctival recurrence, presumably by perpetuating chronic inflammation mediated by T-helper (Th)17 lymphocytes.

The Hirsch index: more than a number?

The Hirsch index: more than a number?

Zebrafish deficient for Muscleblind-like 2 exhibit features of myotonic dystrophy.

SUMMARYMyotonic dystrophy (DM; also known as dystrophia myotonica) is an autosomal dominant disorder that affects the heart, eyes, brain and endocrine system, but the predominant symptoms are neuromuscular, with progressive muscle weakness and wasting. DM presents in two forms, DM1 and DM2, both of which are caused by nucleotide repeat expansions: CTG in the DMPK gene for DM1 and CCTG in ZNF9 (CNBP) for DM2. Previous studies have shown that the mutant mRNAs containing the transcribed CUG or CCUG repeats are retained within the nuclei of cells from individuals with DM, where they bind and sequester the muscleblind-like proteins MBNL1, MBNL2 and MBNL3. It has been proposed that the sequestration of these proteins plays a key role in determining the classic features of DM. However, the functions of each of the three MBNL genes are not completely understood. We have generated a zebrafish knockdown model in which we demonstrate that a lack of mbnl2 function causes morphological abnormalities at the eye, heart, brain and muscle levels, supporting an essential role for mbnl2 during embryonic development. Major features of DM are replicated in our model, including muscle defects and splicing abnormalities. We found that the absence of mbnl2 causes disruption to the organization of myofibrils in skeletal and heart muscle of zebrafish embryos, and a reduction in the amount of both slow and fast muscle fibres. Notably, our findings included altered splicing patterns of two transcripts whose expression is also altered in DM patients: clcn1 and tnnt2. The studies described herein provide broader insight into the functions of MBNL2. They also lend support to the hypothesis that the sequestration of this protein is an important determinant in DM pathophysiology, and imply a direct role of MBNL2 in splicing regulation of specific transcripts, which, when altered, contributes to the DM phenotype.

Neuroprotective Effect of Hyperbaric Oxygen Therapy on Anterior Ischemic Optic Neuropathy

The study investigated the therapeutic effect of hyperbaric oxygen (HBO) on anterior ischemic optic neuropathy in a rodent model (rAION). rAION was laser-induced in one eye of 63 mice. The fellow (uninjured) eye served as an internal control. Thirty-three mice underwent two 90-min sessions of 100% oxygen (2 atm) treatment immediately following injury and one session daily thereafter for up to 14 days. The remaining mice were untreated. Retinas were harvested at different time points, and mRNA levels of various genes were analyzed by real-time polymerase chain reaction and histologic study. Untreated mice: day 1 post-rAION – SOD-1 (oxidative-stress-related) decreased to 82% of control (uninjured eye) levels (P < 0.05), Caspase-3 (proapoptotic) decreased to 89%, Bcl-xL mildly increased (117%; all NS); day 3 – HO-1 and endothelial nitric oxide synthase (eNOS; ischaemia-related) decreased to 74%, and Bcl-2-associated X protein, Caspase-3, and B-cell lymphoma 2 (Bcl-2; apoptotic) increased by 170, 120, and 111%, respectively (all NS); day 21 – HO-1 increased to 222% (NS) and eNOS decreased to 48% (P < 0.05). Treated mice: day 1 – SOD-1 and Caspase-3 remained unchanged, Bcl-2 and Bcl-xL mildly increased (112 and 126% respectively); day 3 – HO-1 and eNOS increased, apoptosis-related gene decreased; day 21 – SOD-1 decreased whereas eNOS increased (P < 0.05), and HO-1 increased to a lesser degree than without treatment. None of the oxygen-treated animals had retinal ganglion cell loss or a decrease in Thy-1 expression. In conclusion, HBO treatment after rAION induction influences the expression of apoptosis-related genes as well as oxidative-stress-induced and ischaemia-related genes and may exert a neuroprotective effect.

Motorcycle Characteristics for Sight Distance Investigation on Exclusive Motorcycle Lanes

In developing Association of Southeast Asian Nations (ASEAN) countries, the motorcycle is a popular means of transportation because it is cheap and provides flexible door-to-door mobility. However, motorcyclists are also highly involved in road accidents. Separating motorcycles from other vehicles in traffic by providing motorcycle lanes is a good engineering measure to improve the safety of motorcyclists. In designing motorcycle lanes, considerations of geometrical elements such as horizontal and vertical curve lengths, stopping distances, and passing sight distances are essential. This study attempts to quantify the eye levels and head levels of motorcycle riders and motorcycle headlight and taillight height characteristics that influenced these geometrical elements. Characteristics of the motorcycles observed along the existing exclusive motorcycle lanes in Selangor state of Malaysia were transcribed from a camcorder, using reference dimension. Findings recommend a design motorcycle eye height of 1,350 mm (5th percentile), headlight height of 800 mm (5th percentile), and taillight height of 625 mm (5th percentile). A motorcyclist height of 1,525 mm (10th percentile) is recommended for the design of sight distance. Recommended heights reduce the cost of motorcycle lane construction with demonstrated safety compared with the current criteria.

Vertical and horizontal references determined by linear perspective and optic flow information

Judging the height and laterality of an object requires vertical and horizontal references that coincide respectively, with the judged eye level and midline of the body trunk. What visual cues determine these references? We previously found that the focus of expansion (FOE) of the optic flow determines judged eye level (Wu et al, VSS02). Here, we extended the study to the horizontal reference. In a virtual environment, observers judged the midline while viewing optical flow display with its FOE shifted horizontally (±10, ±20 and ±30deg). As predicted, horizontal midline was biased to the FOE [rate=0.20 (left); 0.29 (right)]. Arguably, besides showing the utility of the optic flow, our study also implies that other stable cues, eg linear perspective cue (Sedgwick, 1986), can help determine the references. To test this, observers judged their eye levels in the dark. In condition 1, two fluorescent lines (2.5m long) were placed on the right wall with their relative orientation varied to cause false linear perspective. Compared to baseline (parallel lines/true linear perspective), judged eye level was affected by false linear perspective. For example, with one line parallel to the floor, judged eye level changed with the orientation of the second line. If the two lines converged below the actual eye level, judged eye level shifted down. That the effect was mainly due to false linear perspective was shown by removing the line parallel to the floor; the orientation of the second line produced only about 1/9th of the effect. In condition 2, we placed a fluorescent line on each side of a wall (1.5m apart). While the pair of lines remained parallel at the same height, their orientation relative to the floor varied (0, 5, 10deg). Again, relative to baseline, judged eye level changed at a rate of 0.18 as the orientation of the lines varied, compared to a single tilted line (rate=0.06). These findings highlight the role of environmental constants in space vision.

Mirrors of visual worlds - from mice to men. What retinal topographies may tell us about mammalian visual ecologies

Event Abstract Back to Event Mirrors of visual worlds - from mice to men. What retinal topographies may tell us about mammalian visual ecologies Peter Ahnelt1* 1 Medical University of Vienna, Department of Physiology, Austria The adult mammalian photoreceptor mosaic of mammals is relatively stable. Thus, its composition and topographic organization may reflect the distribution of vitally relevant and statistically dominant image content for downstream processing. While 5 photopigment classes were present in ancestral vertebrates, molecular genetics has confirmed a reduced set of merely 1 rod and 2 cone opsins in placental mammals (improved by gene duplication/polymorphism in primates). Still, a large range of rod/cone proportions and topographic variants of spectral cone sub-mosaics emerged for matching the radiation of mammalian groups into most ecological niches. A general trend towards elongated retinal topographies (visual streaks) is present in terrestrial open-habitat species. Recent studies on more than 20 ungulate species have revealed the plasticity of this streak-type design. Correlated with parameters such as body size and habitat structure, the streak is complemented by additional higher density regions. A foveo-concentric pattern, as is found most diurnal primates, is consistently associated with arboreal lifestyles and omni-directional weighting of perceptual space. Yet, (semi-) terrestrial baboons and mandrils too reveal a clear density rise along the horizontal meridian. In contrast, terrestrial homo still expresses largely iso-centric gradients, thus matching the patterns of (semi-) arboreal macaques. We suggest this conservative trait to be linked to the evolution of bipedality. Erect posture has not only elevated eye levels but also required to maintain visual control on the foreground. Obstructive snouts are compatible with proclined quadrupedal postures, while Homo erectus shows a co-evolutive trend of facial flattening, simultaneously gaining for super-vision of freed forelimbs. Comparison of visual field limits by virtual ray tracing confirms a downwards-shift of the human vertical range in comparison to chimpanzee and baboon. Conference: IBRO International Workshop 2010, Pécs, Hungary, 21 Jan - 23 Jan, 2010. Presentation Type: Oral Presentation Topic: Vision: from the evolution of retinas to the evolution of ideas Citation: Ahnelt P (2010). Mirrors of visual worlds - from mice to men. What retinal topographies may tell us about mammalian visual ecologies. Front. Neurosci. Conference Abstract: IBRO International Workshop 2010. doi: 10.3389/conf.fnins.2010.10.00243 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 05 May 2010; Published Online: 05 May 2010. * Correspondence: Peter Ahnelt, Medical University of Vienna, Department of Physiology, Vienna, Austria, peter.ahnelt@meduniwien.ac.at Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Peter Ahnelt Google Peter Ahnelt Google Scholar Peter Ahnelt PubMed Peter Ahnelt Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Effective tumor treatment targeting a melanoma/melanocyte-associated antigen triggers severe ocular autoimmunity

Nonmutated tissue differentiation antigens expressed by tumors are attractive targets for cancer immunotherapy, but the consequences of a highly effective antitumor immune response on self-tissue have not been fully characterized. We found that the infusion of ex vivo expanded adoptively transferred melanoma/melanocyte-specific CD8+ T cells that mediated robust tumor killing also induced autoimmune destruction of melanocytes in the eye. This severe autoimmunity was associated with the up-regulation of MHC class I molecules in the eye and high levels of IFN-gamma derived from both adoptively transferred CD8+ T cells and host cells. Furthermore, ocular autoimmunity required the presence of the IFN-gamma receptor on target tissues. Data compiled from >200 eyes and tumors in 10 independently performed experiments revealed a highly significant correlation (P < 0.0001) between the efficacy of tumor immunotherapy and the severity of ocular autoimmunity. Administration of high doses of steroids locally mitigated ocular autoimmunity without impairing the antitumor effect. These findings have particular importance for immunotherapies directed against self-antigens and highlight the need for targeting unique tumor antigens not expressed in critical tissues.

Visual prognosis and vitreous cytokine levels after arteriovenous sheathotomy in branch retinal vein occlusion associated with macular oedema

To investigate the relationship between vitreous levels of cytokines, including interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF), and visual prognosis after pars plana vitrectomy (PPV) with arteriovenous sheathotomy in patients with branch retinal vein occlusion (BRVO) associated with macular oedema. We studied 60 patients with logMAR visual acuity (VA) scores of < 0.3 and visual impairment secondary to BRVO-associated macular oedema. All patients underwent PPV with arteriovenous sheathotomy. At the time of PPV, vitreous samples were collected from the operated eye and vitreous levels of VEGF and IL-6 were measured. Best corrected VA (BCVA) (using a logMAR chart) and foveal thickness (FT) (using optical coherence tomography) were monitored for up to 6 months after PPV. Both BCVA and FT significantly improved after PPV. According to multiple regression analysis, both the improvement in BCVA and decrease in FT were closely related to the vitreous level of IL-6 but not to that of VEGF. The vitreous level of VEGF was strongly correlated with duration of BRVO. Both improvement in BCVA and decrease in FT were observed after PPV in BRVO patients with macular oedema. Interestingly, these visual prognoses strongly correlate with the vitreous level of IL-6, whereas the duration of BRVO strongly correlates with the vitreous level of VEGF.

Judgments of Visually Perceived Eye Level (VPEL) in Outdoor Scenes: Effects of Slope and Height

When one looks up a hill from below, its peak appears lower than it is; when one looks at a hill across a valley from another peak, the peak of that hill appears higher than it is. These illusions have sometimes been explained by assuming that the subjective horizontal is assimilated to the nearby slope: when looking up a slope, the subjective horizontal is raised, diminishing the height of the peak above the subjective horizontal, and making the peak appear lower than it is. When looking down a slope towards another hill, the subjective horizontal is lowered, increasing the height of that hill above the subjective horizontal, and making its peak appear higher than it is. To determine subjective horizontals we measured visually perceived eye levels (VPELs) in 21 real-world scenes on a range of slopes. We found that VPEL indeed assimilates by about 40% to slopes between 7 degrees downhill and 7 degrees uphill. For larger uphill slopes up to 23 degrees, VPEL asymptotes at about 4.5 degrees. For larger downhill slopes, the assimilation of VPEL diminishes, and at 23 degrees is raised by about 1 degree. These results are consistent with the assimilation explanation of the illusions if we assume that steep downhill slopes lose their effectiveness by being out of view. We also found that VPEL was raised when viewing from a height, in comparison with ground-level views, perhaps because the perceived slope increases with viewing height.

The linear perspective information in ground surface representation and distance judgment

Most ground surfaces contain various types of texture gradient information that serve as depth cues for space perception. We investigated how linear perspective, a type of texture gradient information on the ground, affects judged absolute distance and eye level. Phosphorescent elements were used to display linear perspective information on the floor in an otherwise dark room. We found that observers were remarkably receptive to such information. Changing the configuration of the linear perspective information from parallel to converging resulted in relatively larger judged distances and lower judged eye levels. These findings support the proposals that (1) the visual system has a bias for representing an image of converging lines as one of parallel lines on a downward-slanting surface and (2) the convergence point of a converging-lines image represents the eye level. Finally, we found that the visual system may be less sensitive to the manipulation of compression gradient information than of linear perspective information.