Abstract: Myopia in children remains a major public health problem worldwide, especially in some Asian countries such as China, Singapore and Japan. Although many interventions have been attempted, few has been proven to be effective in controlling onset and progression of myopia in children. Environmental factors, genetic susceptibility or ethnic differences can affect the efficacy of these interventions. However, many questions remain unclear and even controversial for controlling myopia. China has the biggest population with myopia, especially for children myopia. Thus, it is of importance to present what achievements Chinese scientists have made in the field of myopia control in children. We summarize the current findings on myopia control in children from the Anyang Childhood Eye Study, including epidemiological data, clinical trials, systematic reviews and meta-analyses, and compare them with studies in other countries to find potential clues for controlling myopia in children.
Abstract: Between 2011 and 2013, two large-scale cohort epidemiology studies were launched in Shanghai: the SCALE study, which aimed to provide ocular public health services to cover the entire youth population in Shanghai, and the SCES, which was based on sample surveys and aimed to provide information on the prevalence and incidence of visual impairment and different types of refractive errors. A total of 910,245 children and adolescents were finally enrolled in the SCALE study; three possible methods for monitoring refractive error without mydriasis were tested, and the agreement between the refractive outcomes of three commonly used autorefractors were examined to ensure the accuracy of the results of the SCALE study. A total of 8,627 children were enrolled in the SCES, and the baseline prevalence of different refractive errors, different behaviors associated with 1 year myopic shifts, and the different patterns of 2-year myopia progression between internal migrant and local resident school children have been analyzed. In some subset samples of the SCALE study and the SCES, several refraction components such as choroidal thickness (ChT) and crystalline lens power were also measured, to further elucidate the relationships between the refraction components and myopia as well as the mechanism of myopia incidence and development. The three methods used in Shanghai to prevent and intervene with childhood myopia: increasing outdoor time, low concentration atropine, and use of orthokeratology lens are also addressed in this review.
Background: To compare objective electrophysiological contrast sensitivity function (CSF) in patients implanted with either multifocal intraocular lenses (MIOLs) or monofocal intraocular lenses (IOLs) by pattern reversal visual evoked potentials (prVEP) measurements.
Methods: Fourty-five cataract patients were randomly allocated to receive bilaterally: apodized diffractive-refractive Alcon Acrysof MIOL (A), full diffractive AMO Tecnis MIOL (B) or monofocal Alcon Acrysof IOL (C). Primary outcomes: 1-year differences in objective binocular CSF measured by prVEP with sinusoid grating stimuli of 6 decreasing contrast levels at 6 spatial frequencies. Secondary outcomes: psychophysical CSF measured with VCTS-6500, photopic uncorrected distance (UDVA), and mesopic and photopic uncorrected near and intermediate visual acuities (UNVA and UIVA respectively).
Results: Electrophysiological CSF curve had an inverted U-shaped morphology in all groups, with a biphasic pattern in Group B. Group A showed a lower CSF than group B at 4 and 8 cpd, and a lower value than group C at 8 cpd. Psychophysical CSF in group A exhibited a lower value at 12 cpd than group B. Mean photopic and mesopic UNVA and UIVA were worse in monofocal group compared to the multifocal groups. Mesopic UNVA and UIVA were better in group B.
Conclusions: Electrophysiological CSF behaves differently depending on the types of multifocal or monofocal IOLs. This may be related to the visual acuity under certain conditions or to IOL characteristics. This objective method might be a potential new tool to investigate on MIOL differences and on subjective device-related quality of vision.
Abstract: The article discusses the early abandonment of mechanical theories about eye enlargement in degenerative myopia at the turn of the 20th century. At that time, the number of theories about myopia grew unrestricted, but with scant support from the experimental field. The mechanical theories vanished as a new wave of metabolism-based theories appeared, propelled by the huge advances in molecular biology. Modern techniques allow reconsidering those theories and to put them to test with higher confidence.
Background: Dementia is a syndrome that affects a person’s ability to understand and express information. The higher prevalence of vision and/or hearing losses among persons with dementia in long-term care (LTC) facilities interferes with the ability of nurses to provide optimal care because communication is compromised. Therefore, the detection and screening for sensory impairment is of the utmost importance in LTC facilities; however, there is currently no agreement among nursing professionals on how to best identify such losses for the purpose of further referral, and the need for a validated screening measure suitable for nurses in LTC facilities is clear. The present project aims to close this gap by investigating the screening recommendations of vision- and hearing-care professionals working with clients affected by dementia.
Methods: Eleven experts in audiology, optometry, deafblindness, and technology participated in individual semi-structured interviews on the topic of tools and strategies that can be used to screen individuals with dementia for sensory loss. Interview transcripts were coded by two evaluators using verbal agreement and consensus building.
Results: Three main themes emerged from the interviews with experts: barriers, facilitators, and strategies. Barriers to sensory screening were often mentioned, particularly impaired communication and lack of staff cooperation. Facilitators consisted uniquely of people, such as family members, intervenors, and nurses. Strategies for sensory screening in this population consisted of improving communication through repetition and encouragements; considerations based on familiarity; and inferring an impairment on the basis of patient behaviour. Few of our interviewees were knowledgeable on the topic of screening apps.
Conclusions: Our findings, to be integrated with a similar environmental scan conducted among LTC nurses, can inform the administration of sensory impairment screening tests among a population with dementia in order to optimize care.
Background: The perceptions surrounding assistive technology have been shown to be increasingly stigmatizing in older adult populations. This stigmatization can lead individuals to the abandonment of the assistive device. Until now, the methods of identifying or predicting the stigma surrounding assistive technology has mostly been qualitative in nature. Here we present a novel quantitate and qualitative research study that uses neuro-cognitive (psychophysics and EEG) and eye tracking technology, in addition to a new questionnaire to investigate the stigma associated with assistive devices. Therefore, this approach plays a major role in understanding and predicting the neural and physiological correlates associated to stigma.
Methods: Thirty-four older adults (>50 years) took part in the study. To determine the psychophysiological predictors of stigma surrounding assistive technologies, we monitored brain activity using EEG, heart rate and eye movements using an eye-tracker while participants viewed a series of images containing either an older or younger individual in different social scenarios (e.g., talking to doctor, at coffee shop). In each scenario, the individual uses either no assistive device, a low stigmatizing device (e.g., iPad), or a high stigmatizing device (e.g., electronic magnifier).
Results: Here we present preliminary analysis of the eye movement data. Analysis shows that in comparison to images that contained a low stigmatizing device, in images that contain high stigmatizing devices, the latency to fixate the device is shorter, first fixation duration is longer, and the total number of fixations on the device are higher. The environment that the devices is used in has no effect on eye movement metrics.
Conclusions: Although the sample size is small, and based on a healthy older-adult population, these initial observations would indicate that latency to fixate and first fixation duration are predictors of stigma associated with assistive devices. Future research should expand this prediction to those actively using assistive devices, and how the measures predict abandonment over time.
Background: Cognitive control is defined as the ability to act flexibly in the environment by either behaving automatically or inhibiting said automatic behaviour and it can be measured using an interleaved pro/anti-saccade task. Decline in cognitive control has been attributed to normal aging and neurological illnesses such as Parkinson’s disease (PD) as well as decline in other cognitive abilities. This parallel might highlight the role played by cognitive control in information processing and working memory. However, little is known about the relationship between cognitive control and other cognitive processes such as visual memory, decision making, and visual search. We thus propose to correlate the incidence of impaired cognitive control with deficits in visual memory, decision making and visual search in three groups: younger adults, older adults and patients with idiopathic PD.
Methods: Seventy-one participants, namely 34 adults (M =22.75, SD =3.8), 22 older adults (M =67.4, SD =8.3), and 20 PD patients (M =65.59, SD =8.2) performed four tasks: interleaved pro/anti-saccade, visual memory, decision making, and serial and pop-out visual search.
Results: Results show that within each group, anti-saccade error rate (ER) were significantly and negatively correlated with visual memory ER (ryounger =?0.378, P=0.036; rolder =?0.440, Polder =0.046; rPD =?0.609, P=0.016). On the other hand, correct decision-making reaction times (RT) were significantly correlated with anti-saccade ER, and RTs only in older adults (rER =0.529, P=0.014; rRT =0.512, P=0.018) and PD patients (rER =0.727, P=0.012; rRT =0.769, P=0.001). For visual search, PD patients showed a significant relationship between RTs for correct pro-saccades and pop-out (r=0.665, P=0.007), and serial (r=0.641, P=0.010) search RTs. Furthermore, there was a significant correlation between MoCA scores and anti-saccade RTs (r=?0.559, P=0.030) and ER (r=?0.562, P=0.029) in PD patients. Taken together, these results support the hypothesis of PD patients’ reliance on bottom-up processes as top-down processes decline. For younger adults, there was a significant correlation between serial search performance and both anti-saccade ER (r=0.488, P=0.005), and correct pro-saccade ER (r=0.413, P=0.021). In older adults, this relationship was absent, but anti-saccade ER significantly correlated with pop-out search times (r=0.473, P=0.030).
Conclusions: We found significant relationships between cognitive tasks and cognitive control as measured through the interleaved pro/anti-saccade task across and within participant groups, providing evidence of the appropriateness of the use of the interleaved pro/anti-saccade task as a measure of overall cognitive control.
Background: The perception of visual forms is crucial for effective interactions with our environment and for the recognition of visual objects. Thus, to determine the codes underlying this function is a fundamental theoretical objective in the study of the visual forms perception. The vast majority of research in the field is based on a hypothetico-deductive approach. Thus, we first begin by formulating a theory, then we make predictions and finally we conduct experimental tests. After decades of application of this approach, the field remains far from having a consensus as to the traits underlying the representation of visual form. Our goal is to determine, without theoretical a priori or any bias whatsoever, the information underlying the discrimination and recognition of 3D visual forms in normal human adults.
Methods: To this end, the adaptive bubble technique developed by Wang et al. [2011] is applied on six 3D synthetic objects under varying views from one test to another. This technique is based on the presentation of stimuli that are partially revealed through Gaussian windows, the location of which is random and the number of which is established in such a way as to maintain an established performance criterion. Gradually, the experimental program uses participants’ performance to determine the stimulus regions that participants use to recognize objects. The synthetic objects used in this study are unfamiliar and were generated from a program produced at C. Edward Connor’s lab, Johns Hopkins University School of Medicine.
Results: The results were integrated across participants to establish regions of presented stimuli that determine the observers’ ability to recognize them—i.e., diagnostic attributes. The results will be reported in graphical form with a Z scores mapping that will be superimposed on silhouettes of the objects presented during the experiment. This mapping makes it possible to quantify the importance of the different regions on the visible surface of an object for its recognition by the participants.
Conclusions: The diagnostic attributes that have been identified are the best described in terms of surface fragments. Some of these fragments are located on or near the outer edge of the stimulus while others are relatively distant. The overlap is minimal between the effective attributes for the different points of view of the same object. This suggests that the traits underlying the recognition of objects are specific to the point of view. In other words, they do not generalize through the points of view.
Background: Retinol dehydrogenase 8 (RDH8) is a 312-amino acid (aa) protein involved in the visual cycle. Bound to the outer segment disk membranes of photoreceptors, it reduces all-trans-retinal to all-trans-retinol1 as one of the rate-limiting steps of the visual cycle2. RDH8 is a member of the short-chain dehydrogenase/reductase family. Its C-terminal segment allows its membrane-anchoring through the postulated presence of an amphipathic α-helix and of 1 to 3 acyl groups at positions 299, 302 and 3043. The secondary structure and membrane binding characteristics of RDH8 and its C-terminal segment have not yet been described.
Methods: To evaluate the membrane binding of RDH8, the full-length protein (aa 1–312), a truncated form (aa 1–296), its C-terminal segment (aa 281–312 and 297–312) as well as different additional variants of this segment were used. The truncated protein binds membranes less efficiently than the full-length form. Thus, the C-terminal segment of RDH8 is essential for the binding and has thus been further examined. The intrinsic fluorescence of tryptophan residues at positions 289 and 310 of the wild-type C-terminal segment of RDH8 and the mutants W289F, W310F and W310R have thus been used to determine their extent of binding to lipid vesicles and to monitor their local environment. Unilamellar lipid vesicles composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) or a mixture of POPC and 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-L-serine (POPS) were used to mimic the phospholipid content of the outer segment disk membranes of photoreceptors.
Results: An increase in fluorescence intensity and in fluorescence lifetime is observed upon increasing the concentration of lipid vesicles. These data allowed calculating values of partition coefficient of the C-terminal segment of RDH8 varying between Kp =1.1 E6 to 1.7 E6. It is noteworthy that the observation of a more intense shift to lower wavelengths upon membrane binding of the mutant W310R and W310F indicates a deeper incorporation of the remaining tryptophan residue at position 289 into the lipid bilayer. The secondary structure of the C-terminal segment of RDH8 observed by circular dichroism and infrared spectroscopy shows a superposition of α-helical, β-turn and unordered structures.
Conclusions: The peptides derived from the C-terminal segment of RDH8 show a strong binding to lipid vesicles. These strength of binding is independent of the type of lipid and the presence of a mutation.
Abstract: Mononuclear phagocytes (MP) comprise a family of cells that include microglial cells (MC), monocytes, and macrophages. The subretinal space, located between the RPE and the photoreceptor outer segments, is physiologically devoid of MPs and a zone of immune privilege mediated, among others, by immunosuppressive RPE signals. Age-related macular degeneration (AMD) is a highly heritable major cause of blindness, characterized by a breakdown of the subretinal immunosuppressive environment and an accumulation of pathogenic inflammatory MPs. Studies in mice and humans suggest that the AMD-associated APOE2 isoform promotes the breakdown of subretinal immunosuppression and increased MP survival. Of all genetic factors, variants of complement factor H (CFH) are associated with greatest linkage to AMD. Using loss of function genetics and orthologous models of AMD, we provide mechanistic evidence that CFH inhibits the elimination of subretinal MPs. Importantly, the AMD-associated CFH402H isoform markedly increased this inhibitory effect on microglial cells, indicating a causal link to disease etiology. Pharmacological acceleration of resolution of subretinal inflammation might be a powerful tool for controlling inflammation and neurodegeneration in late AMD.
