Publications

2017

Gonzalez-Andrades M, Mata R, González-Gallardo MDC, Medialdea S, Arias-Santiago S, Martínez-Atienza J, Ruiz-García A, Pérez-Fajardo L, Lizana-Moreno A, Garzon I, Campos A, Alaminos M, Carmona G, Cuende N. A study protocol for a multicentre randomised clinical trial evaluating the safety and feasibility of a bioengineered human allogeneic nanostructured anterior cornea in patients with advanced corneal trophic ulcers refractory to conventional treatment. BMJ Open. 2017;7(9):e016487.
INTRODUCTION: There is a need to find alternatives to the use of human donor corneas in transplants because of the limited availability of donor organs, the incidence of graft complications, as well as the inability to successfully perform corneal transplant in patients presenting limbal deficiency, neo-vascularized or thin corneas, etc. We have designed a clinical trial to test a nanostructured fibrin-agarose corneal substitute combining allogeneic cells that mimics the anterior human native cornea in terms of optical, mechanical and biological behaviour. METHODS AND ANALYSIS: This is a phase I-II, randomised, controlled, open-label clinical trial, currently ongoing in ten Spanish hospitals, to evaluate the safety and feasibility, as well as clinical efficacy evidence, of this bioengineered human corneal substitute in adults with severe trophic corneal ulcers refractory to conventional treatment, or with sequelae of previous ulcers. In the initial phase of the trial (n=5), patients were sequentially recruited, with a safety period of 45 days, receiving the bioengineered corneal graft. In the second phase of the trial (currently ongoing), subjects are block randomised (2:1) to receive either the corneal graft (n=10), or amniotic membrane (n=5), as the control treatment. Adverse events, implant status, infection signs and induced neovascularization are evaluated as determinants of safety and feasibility of the bioengineered graft (main outcomes). Study endpoints are measured along a follow-up period of 24 months, including 27 post-implant assessment visits according to a decreasing frequency. Intention to treat, and per protocol, and safety analysis will be performed. ETHICS AND DISSEMINATION: The trial protocol received written approval by the corresponding Ethics Committee and the Spanish Regulatory Authority and is currently recruiting subjects. On completion of the trial, manuscripts with the results of phases I and II of the study will be published in a peer-reviewed journal. TRIAL REGISTRATION: CT.gov identifier: NCT01765244 (Jan2013). EudraCT number: 2010-024290-40 (Dec2012).
Iao T, Rong SS, Ling AN, Brelén M, Young AL, Chong K. Electrophysiological Studies in Thyroid Associated Orbitopathy: A Systematic Review. Sci Rep. 2017;7(1):12108.
Dysthyroid optic neuropathy (DON) is the commonest cause of blindness in thyroid associated orbitopathy (TAO). While diagnosis remains clinical, objective tests for eyes with early or equivocal findings are lacking. Various electrophysiological studies (EPS) have been reported, yet the types and parameters useful for DON remain inconclusive. We performed a systematic literature search in MEDLINE, EMBASE and the Cochrane databases via the OVID platform up to August 20, 2017. 437 records were identified for screening and 16 original studies (1327 eyes, 787 patients) were eligible for review. Pattern visual evoked potential (pVEP) was the most frequently studied EPS. Eyes of TAO patients with DON showed delayed P100 latencies, decreased P100 amplitudes or delayed N75 latencies during pVEP, compared to those without or healthy controls. Due to study heterogeneity, no quantitative analysis was possible. This review highlights the most common type (pVEP) and useful parameters (P100 latency and amplitude) of EPS, and supports further research on them using standardized testing conditions.
Gipson I, Mandel U, Menon B, Michaud S, Tisdale A, Campos D, Clausen H. Generation and characterization of a monoclonal antibody to the cytoplasmic tail of MUC16. Glycobiology. 2017;27(10):920–926.
MUC16 is a large transmembrane mucin expressed on the apical surfaces of the epithelium covering the ocular surface, respiratory system and female reproductive tract. The transmembrane mucin is overexpressed by ovarian carcinomas, it is one of the most frequently used diagnostic markers for the disease and it is considered a promising target for immunotherapeutic intervention. Immunodetection of the mucin has to date been through antibodies that recognize its exceptionally large ectodomain. Similar to other membrane anchored mucins, MUC16 has a short cytoplasmic tail (CT), but studies of the biological relevance of the C-terminal domain of MUC16 has been limited by lack of availability of monoclonal antibodies that recognize the native CT. Here, we report the development of a novel monoclonal antibody to the CT region of the molecule that recognizes native MUC16 and its enzymatically released CT region. The antibody is useful for immunoprecipitation of the released CT domain as demonstrated with the OVCAR3 ovarian cancer cell line and can be used for detailed cytolocalization in cells as well as in frozen sections of ocular surface and uterine epithelium.
Foulsham W, Marmalidou A, Amouzegar A, Coco G, Chen Y, Dana R. Review: The function of regulatory T cells at the ocular surface. Ocul Surf. 2017;15(4):652–659.
Regulatory T cells (Tregs) are critical modulators of immune homeostasis. Tregs maintain peripheral tolerance to self-antigens, thereby preventing autoimmune disease. Furthermore, Tregs suppress excessive immune responses deleterious to the host. Recent research has deepened our understanding of how Tregs function at the ocular surface. This manuscript describes the classification, the immunosuppressive mechanisms, and the phenotypic plasticity of Tregs. We review the contribution of Tregs to ocular surface autoimmune disease, as well as the function of Tregs in allergy and infection at the ocular surface. Finally, we review the role of Tregs in promoting allotolerance in corneal transplantation.
Chou J, Kosowsky T, Payal A, Gonzalez Gonzalez L, Daly M. CONSTRUCT AND FACE VALIDITY OF THE EYESI INDIRECT OPHTHALMOSCOPE SIMULATOR. Retina. 2017;37(10):1967–1976.
PURPOSE: To evaluate construct and face validity of the Eyesi Binocular Indirect Ophthalmoscope Simulator. METHODS: The performance of 25 medical students (Group A) was compared with that of 17 ophthalmology and optometry trainees (Group B) on the Eyesi Binocular Indirect Ophthalmoscope Simulator. During the course of a single session, each participant viewed an orientation module followed by an instruction session and a demonstration case, and performed 6 cases of progressively increasing difficulty (4 levels) and a 10-question face validity questionnaire. Outcomes included total score, total examination time, percent retina examined, and duration of eye exposure to light. RESULTS: Group B achieved significantly better total scores than Group A on all difficulty levels (P = 0.02, P = 0.001, P = 0.001, and P = 0.0001, for Levels 1-4, respectively) and had a significantly faster mean duration of examination (8 minutes 58 seconds vs. 5 minutes 21 seconds, P < 0.0001). Medical students reported higher scores in the face validity questionnaire for the simulator experience being helpful at orienting them to true indirect ophthalmology, and that further training on the simulator would improve their skills in the clinic (P = 0.03 for all). CONCLUSION: The Eyesi Binocular Indirect Ophthalmoscope Simulator has significant construct and face validity and shows promise for medical education.
PURPOSE: In advanced Fuchs endothelial corneal dystrophy (FECD), central endothelial changes do not correlate with disease severity. The peripheral endothelial cell count (ECC) has not been studied as a marker of FECD severity. The goal of this study was to determine the relationship between the peripheral ECC and known clinical markers of FECD in advanced cases. METHODS: Patients with FECD examined between January 1, 2013, and September 1, 2016, by 1 cornea specialist were identified. Medical records from all previous visits were reviewed to include eyes with high-quality central and peripheral in vivo confocal microscopy images performed on the same day as a clinical evaluation. Endothelial photographs were used to perform manual cell counts centrally and peripherally. Clinical grading of FECD from 1 to 4 was performed at the slit-lamp. RESULTS: We identified 154 eyes of 126 patients that met criteria for inclusion. With higher disease grades, central ECC and peripheral ECC decreased, visual acuity worsened, and central corneal thickness (CCT) increased (all P < 0.05). In patients with advanced disease (defined as either grade 3 or 4, CCT >700, or central ECC <350), the peripheral ECC was the best predictor of disease severity and had the highest number of statistically significant correlations with other clinical markers compared with competing variables. CONCLUSIONS: In advanced FECD, severity is best determined by the peripheral ECC compared with the central ECC, visual acuity, clinical disease grade, and CCT. The peripheral ECC should be added to the clinical parameters used to evaluate FECD severity.
Ousler G, Rimmer D, Smith L, Abelson M. Use of the Controlled Adverse Environment (CAE) in Clinical Research: A Review. Ophthalmol Ther. 2017;6(2):263–276.
The many internal and external factors that contribute to the pathophysiology of dry eye disease (DED) create a difficult milieu for its study and complicate its clinical diagnosis and treatment. The controlled adverse environment (CAE®) model has been developed to minimize the variability that arises from exogenous factors and to exacerbate the signs and symptoms of DED by stressing the ocular surface in a safe, standardized, controlled, and reproducible manner. By integrating sensitive, specific, and clinically relevant endpoints, the CAE has proven to be a unique and adaptable model for both identifying study-specific patient populations with modifiable signs and symptoms, and for tailoring the evaluation of interventions in clinical research studies.
Sobrin L, Chong YH, Fan Q, Gan A, Stanwyck L, Kaidonis G, Craig J, Kim J, Liao WL, Huang YC, Lee WJ, Hung YJ, Guo X, Hai Y, Ipp E, Pollack S, Hancock H, Price A, Penman A, Mitchell P, Liew G, Smith A, Gudnason V, Tan G, Klein B, Kuo J, Li X, Christiansen M, Psaty B, Sandow K, Asian Genetic Epidemiology Network Consortium, Jensen R, Klein R, Cotch MF, Wang JJ, Jia Y, Chen C, Chen YDI, Rotter J, Tsai FJ, Hanis C, Burdon K, Wong TY, Cheng CY. Genetically Determined Plasma Lipid Levels and Risk of Diabetic Retinopathy: A Mendelian Randomization Study. Diabetes. 2017;66(12):3130–3141.
Results from observational studies examining dyslipidemia as a risk factor for diabetic retinopathy (DR) have been inconsistent. We evaluated the causal relationship between plasma lipids and DR using a Mendelian randomization approach. We pooled genome-wide association studies summary statistics from 18 studies for two DR phenotypes: any DR (N = 2,969 case and 4,096 control subjects) and severe DR (N = 1,277 case and 3,980 control subjects). Previously identified lipid-associated single nucleotide polymorphisms served as instrumental variables. Meta-analysis to combine the Mendelian randomization estimates from different cohorts was conducted. There was no statistically significant change in odds ratios of having any DR or severe DR for any of the lipid fractions in the primary analysis that used single nucleotide polymorphisms that did not have a pleiotropic effect on another lipid fraction. Similarly, there was no significant association in the Caucasian and Chinese subgroup analyses. This study did not show evidence of a causal role of the four lipid fractions on DR. However, the study had limited power to detect odds ratios less than 1.23 per SD in genetically induced increase in plasma lipid levels, thus we cannot exclude that causal relationships with more modest effect sizes exist.
Wolfe J. Visual Attention: Size Matters. Curr Biol. 2017;27(18):R1002-R1003.
When searching real-world scenes, human attention is guided by knowledge of the plausible size of target object (if an object is six feet tall, it isn't your cat). Computer algorithms typically do not do this, but perhaps they should.
Poon LYC, Sola-Del Valle D, Turalba A, Falkenstein I, Horsley M, Kim J, Song B, Takusagawa H, Wang K, Chen T. The ISNT Rule: How Often Does It Apply to Disc Photographs and Retinal Nerve Fiber Layer Measurements in the Normal Population?. Am J Ophthalmol. 2017;184:19–27.
PURPOSE: To determine what percentage of normal eyes follow the ISNT rule, and whether ISNT rule variants may be more generalizable to the normal population. DESIGN: Cross-sectional study. METHODS: Setting: Institutional setting. STUDY POPULATION: Total of 110 normal subjects. OBSERVATION PROCEDURES: Neuroretinal rim assessments from disc photographs and retinal nerve fiber layer (RNFL) thickness measurements from spectral-domain optical coherence tomography. MAIN OUTCOME MEASURES: The percentages of subjects that obeyed the ISNT rule and its variants. RESULTS: The ISNT rule is only valid for 37.0% of disc photograph rim assessments and 43.8% of RNFL measurements. Deviation of the nasal sector from the expected ISNT pattern was a major cause for the ISNT rule not being obeyed for both rim and RNFL assessments. Specifically, 10.9% of subjects had wider nasal rims than the inferior rims, 29.4% had wider nasal rims than the superior rims, 14.7% had narrower nasal rims than the temporal rims, and 42.9% had thinner nasal RNFLs compared to the temporal quadrant. Exclusion of the nasal quadrant from the ISNT rule significantly increased the validity of ISNT variant rules, with 70.9% and 76.4% of disc photographs following the IST rule and the IS rule, respectively. Similarly, for RNFL thickness, 70.9% and 71.8% of patients followed the IST and IS rule, respectively. CONCLUSIONS: The ISNT rule is only valid for about a third of disc photographs and less than half of RNFL measurements in normal patients. ISNT rule variants, such as the IST and IS rule, may be considered, as they are valid in more than 70% of patients.