Background and Objective: Limbal stem cell deficiency (LSCD) describes the clinical condition when there is dysfunction of the corneal epithelial stem/progenitor cells and the inability to sustain the normal homeostasis of the corneal epithelium. The limbal stem cells are located in a specialized area of the eye called the palisades of Vogt (POV). There have been significant advances in the diagnosis and management of LSCD over the past decade and this review focuses on the pathophysiology of LSCD, its clinical manifestations, diagnosis, and causes.

Methods: Papers regarding LSCD were searched using PubMed to identify the current state of diagnosis and causes of LSCD published through to June 2022. 
Key Content and Findings: LSCD is clinically demonstrated by a whorl-epitheliopathy, loss of the POV, and conjunctivalization of the cornea. The diagnosis of this condition is based on clinical examination and aided by the use of impression cytology, in vivo confocal microscopy, and anterior segment optical coherence tomography (asOCT). There are many causes of LSCD, but those which are most common include chemical injuries, aniridia, contact lens wear, and Stevens-Johnson syndrome (SJS).

Conclusions: While this condition is most commonly encountered by corneal specialists, it is important that other ophthalmologists recognize the possibility of LSCD as it may arise in other co-morbid eye conditions.

Background: To assess the safety and efficacy of supracapsular implantation with optic capture of the posterior chamber intraocular lens in Chinese children with aphakic after traumatic cataract.

Methods: It was a retrospective case series study. Fifteen cases (15 eyes) Chinese children received supracapsular implantation with optic capture of the posterior chamber intraocular lens. Pre- and post-operative visual acuities were recorded. Intra- and post-operative complications were observed. The follow-up period ranged from 7 to 43 (28.7±7.2) months.

Results: Implantation of optic capture of the posterior chamber intraocular lens was successfully performed in 15 eyes. The best corrected visual acuity (BCVA) ranged from 0.3 to 1.0 (0.61±0.19). No optic axis opaque was found in 15 eyes with optic capture. The major complications of optic capture were iris posterior synechia and intraocular lens (IOL) precipitates. Intraocular dislocation was found in one case three weeks after the operation.

Conclusions: Supracapsular implantation with optic capture of the posterior chamber intraocular lens is safe and effective for the treatment of traumatic cataract in Chinese children.

Background: To settle the fundamentals of a numerical procedure that relates retinal ganglion-cell density and threshold sensitivity in the visual field. The sensitivity of a generated retina and visual pathways to virtual stimuli are simulated, and the conditions required to reproduce glaucoma-type defects both in the optic-nerve head (ONH) and visual fields are explored.

Methods: A definition of selected structural elements of the optic pathways is a requisite to a translation of clinical knowledge to computer programs for visual field exploration. The program is able to generate a database of normalized visual fields. The relationship between the number of extant receptive fields and threshold sensitivity is plotted for background sensitivity and corresponding automated perimetry. A solution in two planes to the 3D distribution of axons in the ONH is proposed. Visual fields with induced damage in the optic disc are comparable in pattern and quantity to glaucomatous records.

Results: The two-level simulation of the ONH facilitates the analysis of optic-cup/retinal defects. We can generate the virtual optic pathways tailored to the age and morphology of the patient’s eye, and it is possible to reproduce glaucomatous damage by “reverse engineering” engineering. The virtual cortical model renders a quantitative relationship between visual defect and neural damage.

Conclusions: A two-level computing of the retina/optic nerve facilitates the analysis of neuroretinal defects and can be incorporated to automatic perimeters to facilitate visual field analysis.

Background: The purpose of this study is to summarize the application of day surgery combined with fast track program in strabismus operation under general anesthesia.

Methods: The clinical data of 2,000 cases of strabismus patients who had underwent surgery in day surgery or traditional hospitalization in the duration from 2015 to 2016 was retrospectively analyzed. The safety and efficacy were assessed by comparing the average length of stay in hospitals, anesthesia recovery time, patient satisfaction and number of adverse events.

Results: Compared with the traditional group, the average length of stay in hospital and recovery time in day surgery group were significantly lower (P<0.001) and the satisfaction of patient was improved (P<0.05), which were statistically significant difference. Moreover, no adverse events occurred among these patients.

Conclusions: The application of day surgery in strabismus operation under general anesthesia is feasible, which can reduce the recovery time and shorten the hospital stay of patients safely and effectively, and their satisfaction was improved at the same time.

Background: With a large portion of older adults living longer, the number of individuals diagnosed with low vision is increasing. The use of optical coherence tomography/scanning laser ophthalmoscope (OCT/SLO) to diagnose retinal disease has become common place in the last 10 years, yet currently there are no OCT/SLO databases for pathological vision. Our aim is to develop a clinical database of individuals who have drusen (i.e., lipid deposits found under the retina), or have been diagnosed with age-related macular degeneration (AMD), with information as to how the structure of the diseased retina changes over time, as well as measures of visual and cognitive functional performance.

Methods: Fundus photographs and retinal scans will be taken using the same model of optos OCT/SLO located in three test sites (MAB-Mackay Rehabilitation Centre, School of Optometry Clinic at the University of Montreal, and the Lighthouse Institute, New York, USA). For each individual entry in the database, demographic and diagnosis information will be available. All OCT/SLO images will be graded according to the Age-related Eye Disease Study standard, in addition to number and size of drusen, severity of geographic atrophy, severity of pigment mottling and presence of choroidal neovascularization. Retinal topography and Raster scans from the OCT/SLO will provide a cross-sectional look at affected retinas. Fixation stability will be recorded using the SLO function, and present four different tasks that are designed to reproduce typical tasks of daily vision, with each task lasting for 10 seconds. The tasks are cross fixation, face recognition, visual search, and reading. These tasks in addition to the retinal scans will be used to determine the eccentricity of a preferred retinal locus from the anatomical fovea, and can be used as an outcome measure for clinical interventions in visually impaired patients.

Results: The database will be available to professors training eye-care practitioners and rehabilitation specialists as a teaching tool. Students will be able to familiarize themselves with the retina and a variety of AMD-related pathologies before they start working with patients. The database will also be accessible by researchers interested in studying AMD from basic science to epidemiology, to investigate how drusen and AMD impact visual and cognitive functional performance.

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: 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).

Abstract: To describe the current aging population in China and globally, especially as it applies to age-related macular degeneration (AMD). To review the current standards of care for treating both wet (exudative) eAMD and dry (atrophic) aAMD. And to introduce a model for experimentation that is based on the Age-Related Eye Disease Study (AREDS) using eye bank tissue. A literature search that outlines current aging populations, standards of clinical treatment as defined by large, multicenter, randomized clinical trials that present level-I data with a low risk for bias. An experimental model system of AMD is presented that enables scientific analysis of AMD pathogenesis by applying grading criteria from the AREDS to human eye bank eyes. Analysis includes proteomic, cellular, and functional genomics. The standard of care for the treatment of eAMD is currently defined by the use of several anti-vascular endothelial growth (anti-VEGF) agents alone or in combination with photodynamic therapy. Monotherapy treatment intervals may be monthly, as needed, or by using a treat-and-extend (TAE) protocol. There are no proven therapies for aAMD. AMD that is phenotypically defined at AREDS level 3, should be managed with the use of anti-oxidant vitamins, lutein/zeaxanthin and zinc (AREDS-2 formulation). By understanding the multiple etiologies in the pathogenesis of AMD (i.e., oxidative stress, inflammation, and genetics), the use of human eye bank tissues graded according to the Minnesota Grading System (MGS) will enable future insights into the pathogenesis of AMD. Initial AMD management is with lifestyle modification such as avoiding smoking, eating a healthy diet and using appropriate vitamin supplements (AREDS-2). For eAMD, anti-VEGF therapies using either pro re nata (PRN) or TAE protocols are recommended, with photodynamic therapy in appropriate cases. New cellular information will direct future, potential therapies and these will originate from experimental models, such as the proposed eye bank model using the MGS, that leverages the prospective AREDS database.