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: The ORVIS infrastructure aims to facilitate the development and availability of valid and adapted tools that will allow functional, perceptual, cognitive and psychological evaluation of low vision clients by researchers and clinicians who work in low vision and visual impairment rehabilitation.
Methods: The tools developed or documented within ORVIS Infrastructure are tests or questionnaires which allow, or will allow to assess—in an accurate and reliable manner—characteristics related to visual impairment. The tools in development are: (I) questionnaire de repérage des hallucinations visuelles liées au syndrome de Charles-Bonnet (QR-SCB); (II) repérage des personnes agées présentant des INDices de déficience VISUELle (IndiVisuel); (III) mesure de l’impact de la déficience visuelle dans les activités quotidiennes (MIDVAQ) and (IV) M’EYE read test. The directory documents 14 tools and offers—within a descriptive sheet—characteristics, components and metrological properties as supported by cited scientific studies.
Results: The ORVIS Infrastructure, which aims at the development and availability of assessment tools, fills researchers’ and clinicians’ needs for measurement tools that are valid, effective and appropriate for use with a visually impaired clientele. Such tools are, especially in French, little known and hard to find, and represent a precious resource for those who want to evaluate the efficacy of treatments or interventions.
Conclusions: ORVIS is available at www.orvis.vision. Between November 2015 and September 2017, the directory has been accessed 1,383 times by 952 unique visitors.
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: A growing number of older adults with vision loss require vision rehabilitation services to address reading difficulties. Braille may be the most appropriate option for those with functional blindness, poor visual prognoses or dual sensory loss. While standardized braille assessment and training protocols are in place to guide interventions with children, there is a high degree of inconsistency and a lack of evidence-based knowledge about best practices to use with adults and seniors who require braille training. Age-related declines in tactile acuity, motor dexterity and cognition present unique barriers to braille training, but very little is known about the impact of aging on factors related to braille reading performance. The aim of this scoping review is to identify the perceptual, motor, and cognitive factors related to braille reading performance and to determine how these factors have been assessed or measured among blind adults and elderly individuals in prior studies.
Methods: Using the scoping review method, a comprehensive search was conducted in three databases: PubMed, Educational Resource Information Center (ERIC), and the Cochrane library. Two reviewers screened articles for inclusion to ensure internal agreement, based on identified exclusion criteria.
Results: The initial search resulted in 1,565 qualitative and quantitative articles. The results synthesize the perceptual, motor and cognitive factors known to predict braille reading performance, how these variables are impacted by the aging process, and how they have been measured in prior studies.
Conclusions: This scoping review is the first step in working towards the development of evidence-based assessment and training protocols to standardized practice with adult and senior clients who require braille training. It also serves to clarify where current knowledge gaps exist in order to guide future studies on braille reading and aging.
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: This infrastructure delivers biological material necessary for several research projects to Vision Health Research Network investigators (VHRN).
Methods: Héma-Québec is the organism in charge obtaining consent and retrieving donor eyes for patient treatment or for research. In Quebec City, donor eyes are sent to the eye bank of the “Centre Universitaire d’Ophtalmologie” (CUO) of Saint-Sacrement hospital. Technicians at the eye bank evaluate the quality of the tissues. Those unfit for graft are transferred to the infrastructure where the coordinator encodes samples prior to their distribution.
Results: Between 2013 and 2017, 27 fundamental investigators, clinical investigators and collaborators supported by 60 students, trainees and laboratory assistants used this infrastructure to move forward their projects. Since 2013, results from those projects generated 21 scientific publications and 232 presentations. The infrastructure helped VHRN investigators obtain near 4 million dollars in grants from many organisms (CIHR, NSERC, Foundations, etc.). These grants allowed recruitment and formation of highly qualified personnel. Last year (April 2016 to March 2017), 189 corneas and 23 eyes transited through the infrastructure.
Conclusions: This infrastructure is available for all investigators that are members of the VHRN. Many original projects have been elaborated thanks to the human ocular tissues provided by this infrastructure. These projects will advance our knowledge in vision health. A better understanding of eye functions will lead to new treatments for eye diseases.
Background: The purpose of this infrastructure is to provide to the Network researchers a database and diverse related tools for the anatomical and functional analysis of the normal, pathological and surgical cornea.
Methods: This database is composed of normal and pathological individuals, totaling more than 36,000 patients. It includes anatomical and functional imaging data, physiological optics data, psychometric and clinical data (medical history, surgical parameters, acuteness, etc.). Various corneal topography tools were added, giving the database a unique character: tools for analyzing individual maps, average map tools for the study and comparison of populations, 3D modeling and visualization tools, statistical tools, etc. There are also screening tools for detecting various corneal conditions (LASIK, PRK, RK, keratoconus) and for secure data exchange between colleagues.
Results: Several studies were made in recent years thanks to this common infrastructure. For example, this database has provided important information regarding the evolution of the 3D shape of the normal cornea with age and ametropia and has confirmed the mirror symmetry of corneas for the right and the left eyes (enantiomorphism). The different stages of Fuchs’ dystrophy were also characterized to provide essential knowledge for surgery of the posterior layer of the cornea. Our database also allowed studying the anatomy of the wounds and the shape of the cornea before and after a transfixing transplant or an endothelial transplant (DSAEK and DSEK). The data on the characterization of experimentally transplanted corneas with corneal equivalents generated by tissue engineering and the recent addition of clinical data on the replacement of a diseased cornea with a synthetic corneal equivalent (keratoprosthesis) also resulted in several publications. More recently, the database has allowed to develop innovative algorithms to determine the optimal shape of an implant according to the clinical parameters of the recipient. On the other hand, we also demonstrated that the 3D shape of the cornea can be used as a biometric characteristic (such as fingerprints) for identification of individuals for various applications ranging from forensics to secure border crossings. Consequently, a new multimodal database (cornea + iris + eventually retina) was created for the purpose of biometric identifications. This database provides a unique set of anatomical and functional tools for the analysis of the cornea. It is characterized by the scientific quality and large quantity of accumulated information on the cornea and the high-level tools to exploit its content.
Conclusions: The common infrastructure is easily accessible to all VHRN members on request. The database will also be accessible online in 2018 (see http://cvl.concordia.ca for more information).
Background: Because of its superficial anatomical localization, the cornea is particularly vulnerable to abrasive forces and various traumas, which can lead to significant visual impairments. Upon injury of the corneal epithelium, there are important changes that occur in the composition of the underlying extracellular matrix (ECM). Those changes are perceived by the integrins that recognize the ECM components as their ligand and activate different intracellular signalling pathways, ultimately leading to reepithelialisation and reorganization of the injured epithelium, both of which are necessary in order to restore the visual properties of the cornea. The goal of this study was to analyse the impact of the pharmacological inhibition of specific signal transduction mediators of integrin-dependant signalling pathways on corneal wound healing using both monolayers of hCECs and tissue-engineered human corneas (hTECs) as in vitro models.
Methods: hTECs were produced by the self-assembly approach and wounded with a 8-mm diameter biopsy punch. Total RNA and proteins were isolated from the wounded and unwounded hTECs to conduct gene profiling analyses and protein kinase arrays. The wounded tissues were then incubated with the WNK1 inhibitor WNK463 and wound healing was monitored over a period of 6 days. Control corneas were incubated with the vehicle alone (DMSO). The impact of WNK1 inhibition on hCECs monolayers was determined using a scratch wound assay.
Results: Gene profiling analyses and protein kinases arrays revealed important alterations in the expression and activity of several mediators from the integrin-dependent signalling pathways in response to the ECM changes taking place during corneal wound healing. Among these, WNK1 is considerably activated through phosphorylation during corneal wound healing. The pharmacological inhibition of WNK1 by WNK463 significantly reduced the dynamic of corneal wound closure in our hTECs and hCECs monolayers compared to their respective negative controls.
Conclusions: These results allowed the identification of WNK1 kinase as an important player for a proper healing of the cornea. Also, these results allowed for a better understanding of the cellular and molecular mechanisms involved in corneal wound healing and they may lead to the identification of new therapeutic targets in the field of corneal wounds.
Background: Congenital hereditary endothelial dystrophy (CHED) is characterized by blindness at birth or in early infancy resulting from bilateral corneal opacification, and is linked to mutation in the Slc4a11 gene. A Slc4a11 knockout (KO) mouse, generated by gene deletion (Vithana et al. Nat Genet 2006), was acquired in order to study this disease. To confirm the phenotype of this Slc4a11 KO mouse model as a function of age, using the wild type (WT) mouse as a control.
Methods: Genotyping was performed by PCR (REDExtract-N-AmpTM Tissue PCR Kit, Sigma-Aldrich, Oakville, ON). Slc4a11 WT and KO mice populations aged from 5 to 50 weeks were studied (n=5 animals per age group; 5-year age intervals). Slit lamp examination, anterior segment-ocular coherence tomography (OCT930SR; Thorlabs, Inc., Newton, NJ), corneal endothelial cell staining, and scanning (SEM) and transmission (TEM) electron microscopy were used to assess the morphological and cellular differences between the two groups. The expression of basolateral membrane transporter NaBC1 within the corneal endothelium was also assessed using immunohistochemistry.
Results: Diffuse and progressive corneal opacification was observed at the slit lamp in the Slc4a11 KO mice, starting at 10 weeks. The central corneal thickness (CCT) also increased progressively as a function of time. In comparison, Slc4a11 WT corneas remained clear over the entire study period. Early TEM results showed vacuole degeneration of the corneal endothelium in the 15-week KO mouse, which was not seen in the same age WT mouse.
Conclusions: The corneal phenotype of this Slc4a11 KO mouse is representative of the clinical manifestations of CHED in human subjects, confirming the usefulness of this model for studying pathophysiology and therapeutic alternatives for Slc4a11-associated corneal dystrophies.
