Abstract: Optical coherence tomography (OCT) is an ocular imaging technique that can complement the neuro-ophthalmic assessment, and inform our understanding regarding functional consequences of neuroaxonal injury in the afferent visual pathway. Indeed, OCT has emerged as a surrogate end-point in the diagnosis and follow up of several demyelinating syndromes of the central nervous system (CNS), including optic neuritis (ON) associated with: multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and anti-myelin oligodendrocyte glycoprotein (MOG) antibodies. Recent advancements in enhanced depth imaging (EDI) OCT have distinguished this technique as a new gold standard in the diagnosis of optic disc drusen (ODD). Moreover, OCT may enhance our ability to distinguish cases of papilledema from pseudopapilledema caused by ODD. In the setting of idiopathic intracranial hypertension (IIH), OCT has shown benefit in tracking responses to treatment, with respect to reduced retinal nerve fiber layer (RNFL) measures and morphological changes in the angling of Bruch’s membrane. Longitudinal follow up of OCT measured ganglion cell-inner plexiform layer thickness may be of particular value in managing IIH patients who have secondary optic atrophy. Causes of compressive optic neuropathies may be readily diagnosed with OCT, even in the absence of overt visual field defects. Furthermore, OCT values may offer some prognostic value in predicting post-operative outcomes in these patients. Finally, OCT can be indispensable in differentiating optic neuropathies from retinal diseases in patients presenting with vision loss, and an unrevealing fundus examination. In this review, our over-arching goal is to highlight the potential role of OCT, as an ancillary investigation, in the diagnosis and management of various optic nerve disorders.
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.
Abstract: Myasthenia gravis (MG) is an autoimmune antibody-mediated disorder which causes fluctuating weakness in ocular, bulbar and limb skeletal muscles. There are two major clinical types of MG. Ocular MG (OMG) affects extra ocular muscles associated with eye movement and eyelid function and generalized MG results in muscle weakness throughout the body. Patients with OMG have painless fluctuating extra ocular muscles weakness, diplopia and ptosis accompanied by normal visual acuity and pupillary function. Frequently, patients with OMG develop generalized MG over 24 months. Pure OMG is more often earlier in onset (<45 years) than generalized MG. It can also occur as part of an immune-genetic disorder or paraneoplastic syndrome related to thymus tumors. Diagnosis is based on clinical manifestations, laboratory findings, electrophysiological evaluation and pharmacologic tests. Therapeutic strategies for MG consist of symptom relieving medications (e.g., acetylcholine esterase inhibitors), immunosuppressive agents, and surgical intervention (e.g., thymectomy).
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.
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: 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: Understanding factors that contribute to posterior capsular opacification (PCO) development is a significant public concern as treatment can lead to complications. In order to prevent PCO, a better understanding of intraocular lens (IOL) characteristics, including design and material, and patient interaction is required. Herein, we performed a retrospective multivariable analysis to determine which factors (IOL and patient based) were least likely to result in PCO.
Methods: One hundred eighty post-mortem eyes with implanted IOLs were collected from the Minnesota Eye Bank, along with clinical history, including date of cataract surgery and IOL model number. The capsular bag (CB) with the IOL implant was removed from all eyes to obtain digital images. PCO outcome was quantified on CB images using an objective, automated custom image analyzer (Medical Parachute Automated Detector Opacification Software). The software measured intensity and area of the opacification within the IOL optic edge, intra-optic edge (IOE = intensity/area), and in Soemmering’s ring (SR = intensity/area). Epidemiologic analysis assessed which IOL characteristics and patient-related factors correlated with PCO. IOL factors included material, edge design, lens filter, company, IOL model, decentration and time from cataract surgery to death. Patient factors included sex, age and diabetes, among others.
Results: Multivariate analyses showed non-diabetic patients had less PCO (P=0.05). Individuals 50–80 years old compared to 80+ had lower SR PCO (P=0.04). Non-blue light filter IOLs had lower SR and IOE PCO compared to filter IOLs (P=0.03, 0.001). Square and frosted optic edge design had lower SR and IOE PCO rates compared to OptiEdge and round optic edge design (P=0.002, 0.02). The IOL model that had the least PCO was the ZA9003 model, but this was only significant for SR and not IOE PCO (P=0.04). Adjusting for patient-factors, IOL lens model was no longer a confounding factor for PCO. Patients with an IOL implanted for <7 years had lower SR PCO, whereas lower IOE PCO was only seen in implants <4 years old (P=0.0001, 0.04).
Conclusions: In order to generate a lens that does not develop PCO, it is critical to understand the IOL- and patient-related factors that lead to PCO development. Based on our data, the most susceptible patients are elderly and diabetic, and it may be preferable to implant a square and frosted edge lens without blue-light filtering in this cohort.
Background: Epidermolysis bullosa (EB) is a heterogynous group of skin disorders characterized by formation of blisters and erosions of the skin in response to minor trauma. Subtypes include EB simplex (EBS), junctional EB (JEB), dystrophic form of EB (DEB) and finally Kindler syndrome (KS). In addition to dermal manifestation, patients can present with various ophthalmic pathologies.
Methods: We reviewed the pathobiology, epidemiology and management of ocular manifestations as well as current and future innovative therapies for EB.
Results: The severity and incidence of ocular involvement were the highest in the recessive DEB-generalized severe and JEB-generalized severe subtypes. Recurrent corneal erosions and blisters were the most common finding and seem to correlate with skin disease. Other manifestations include corneal scaring, blepharitis, ectropion, symblepharon, infantile cataracts, lacrimal duct obstruction as well as meibomian gland deficiency.
Conclusions: Ophthalmology consult as well as regular follow-up are essential in the multi-disciplinary approach of this disease. Indeed, parents’ and patients’ education as well as early diagnosis and treatment are crucial to prevent permanent and long-term visual disabilities.
