Eye Exposure Research Articles

Toxicity resulting from exposure to oven cleaners as reported to the UK National Poisons Information Service (NPIS) from 2009 to 2015

Introduction: Oven cleaning products contain corrosive substances, typically sodium or potassium hydroxide.Objective: To determine the reported toxicity from exposure to oven cleaning products.Methods: Telephone enquiries to the UK National Poisons Information Service regarding oven cleaning products were analysed retrospectively for the period January 2009 to December 2015.Results: There were 796 enquiries relating to 780 patients. Ninety-six percent of the products involved in the reported exposures contained sodium hydroxide and/or potassium hydroxide. Ingestion alone (n = 285) or skin contact alone (n = 208) accounted for the majority of cases; inhalation alone (n = 101), eye contact alone (n = 97), and multiple routes of exposure (n = 89) accounted for the remainder. Ninety-five percent of patients exposed by inhalation, 94% exposed dermally and 85% reporting eye exposure, developed features of toxicity. Patients exposed by multiple routes developed symptoms in 70% of cases. Only 103 of the 285 patients ingested oven cleaner directly, whereas 182 patients ingested food they considered to have been contaminated with oven cleaner. In 100 of the 103 direct ingestions where the features and World Health Organisation/International Programme on Chemical Safety/European Commission/European Association of Poison Centres and Clinical Toxicologists Poisoning Severity Score were known, 56 reported symptoms which were minor in 51 cases. The most common features following ingestion were vomiting (n = 26), abdominal pain (n = 22) or pharyngitis (n = 15). Skin burns (n = 91) predominantly involving the hands or arms, occurred in 44% of dermal exposures. Following inhalation, patients frequently developed respiratory features (n = 52) including coughing and chest pain/tightness. Eye pain (n = 43) and conjunctivitis (n = 33) commonly occurred following ocular exposure.Conclusions: Most (71%) patients exposed to an oven cleaner irrespective of the route of exposure developed features of toxicity, though in most cases only minor features developed; moderate or severe features ensued in ∼4%. Those patients exposed dermally, ophthalmically or by inhalation developed features more frequently (≥85%) than those who ingested a product directly (56%).

Firecracker eye exposure: experimental study and simulation.

Understanding the mechanisms of traumatic ocular injury is helpful to make accurate diagnoses before the symptoms emerge and to develop specific eye protection. The comprehension of the dynamics of primary blast injury mechanisms is a challenging issue. The question is whether the pressure wave propagation and reflection alone could cause ocular damage. To date, there are dissenting opinions and no conclusive evidence thereupon. A previous numerical investigation of blast trauma highlighted the dynamic effect of pressure propagation and its amplification by the geometry of the bony orbit, inducing a resonance cavity effect and a standing wave hazardous for eye tissues. The objective of the current work is to find experimental evidence of the numerically identified phenomenon. Therefore, tests aimed at evaluating the response of porcine eyes to blast overpressure generated by firecrackers explosion were performed. The orbital cavity effect was considered mounting the enucleated eyes inside a dummy orbit. The experimental measurements obtained during the explosion tests presented in this paper corroborate the numerical evidence of a high-frequency pressure amplification, enhancing the loading on the ocular tissues, attributable to the orbital bony walls surrounding the eye.

Toxicity from automotive screenwashes reported to the United Kingdom National Poisons Information Service (NPIS) from 2012 to 2015

Background: Automotive screenwashes commonly contain ethylene glycol, methanol, and/or isopropanol; ethanol is also included in many formulations. The concentrations and combinations of each constituent vary considerably between the products. This study was undertaken to investigate the toxicity of automotive screenwashes as reported by telephone to the United Kingdom National Poisons Information Service (NPIS).Methods: Enquiries to the NPIS relating to automotive screenwashes were analyzed retrospectively for the period January 2012 to December 2015.Results: There were 295 enquiries involving 255 individual exposures. The majority (n = 241, 94.5%) of exposures involved ingestion and 14 of these also involved other routes. Six cases were due to skin contact alone, three to inhalation alone, three to eye contact alone, one to ear exposure alone and another occurred from inhalation and skin contact. Children below 5 years of age accounted for 26% of all ingestions. The identity (and therefore composition) of the screenwash was known with certainty in 124 of 241 ingestions and included methanol in 106 formulations, isopropanol in 72, ethylene glycol in 38, and ethanol in 104. The World Health Organisation/International Programme on Chemical Safety/European Commission/European Association of Poison Centres and Clinical Toxicologists Poisoning Severity Score was known in 235 of 241 cases of ingestion: most patients were asymptomatic (n = 169, 71.9%), but 59 (25.1%) developed minor (PSS 1), six (2.6%) moderate (PSS 2), and one patient severe (PSS 3) features; this patient later died. Nausea (n = 10), vomiting (n = 11), abdominal pain (n = 10), metabolic acidosis (n = 8) and raised anion gap (n = 8) were reported most commonly after ingestion.Conclusions: Most patients (71.9%) ingesting automotive screenwash did not develop features. The implication is that the amount of screenwash ingested was very small. Skin and eye exposure produced either no features or only minor toxicity.

The impact of an international initiative on exposures to liquid laundry detergent capsules reported to the United Kingdom National Poisons Information Service between 2008 and 2015

Introduction: Although the majority of those exposed to liquid laundry detergent capsules remain asymptomatic or suffer only minor clinical features after exposure, a small proportion develop central nervous system depression, stridor, pulmonary aspiration and/or airway burns following ingestion or conjunctivitis and corneal ulceration following eye exposure. As a consequence, the International Association for Soaps, Detergents and Maintenance Products (AISE) established a Product Stewardship Programme in Europe, requiring that safety measures be implemented to reduce the visibility of, and restrict access to, these detergent capsules by small children. Implementation occurred in the United Kingdom over several months during the first half of 2013.Objective: This study investigated whether the AISE Programme had an impact on the number and severity of exposures reported to the United Kingdom National Poisons Information Service.Methods: Telephone enquiries to the National Poisons Information Service relating to liquid laundry detergent capsules were analysed for the period January 2008 to December 2015.Results: While there was a significant difference (p = 0.0002) between the mean number of annual exposures (469.4) reported between 2008 and 2012 and the mean number reported between 2014 and 2015 (403.5), the number of exposures was decreasing steadily prior to implementation of the Programme in 2013, which did not impact this fall from 2013 onwards. In addition, the number of exposures per million units sold was not impacted by the Programme. There was no significant difference (p = 0.68) between the mean number of exposures (11.8) with PSS ≥2 reported between 2008 and 2012 and the mean number (13.0) reported between 2014 and 2015. Although there was a 28.7% decrease between 2010–2012 and 2014–2015 in the number of exposures with PSS ≥2 per million units sold, this decrease was not statistically significant (p = 0.18).Conclusion: There is no evidence that the Product Stewardship Programme had a beneficial impact on the number of exposures reported to the National Poisons Information Service or their severity.

Use of an Amphoteric Solution in Eye, Skin and Oral Chemical Exposures: Retrospective Multicenter Clinical Case Series

Introduction: A polyvalent amphoteric flushing solution (Diphoterine®) has been in use for a number of years, mainly in industrial settings for decontamination of acid, base, and other corrosive or irritant substances eye and skin splashes. Methods: Retrospective collection of 34 cases from several centers reporting use of Diphoterine® decontamination of eye, skin or oral chemical exposures. The following data were retrieved: exposure circumstances (workplace, domestic, deliberate assault), chemical nature and pH, exposure type, initial clinical signs, clinical signs after flushing, initial and final visual analog scale (VAS) pain ratings, consulting specialist physicians’ conclusions. Results: 58.8% of the 34 cases were occupational exposures, 29.4% were domestic, 5.9% occurred in schools, and 5.9% were deliberate chemical assaults. Of involved chemicals, 11 were basic substances, 11 were acidic, 1 was an oxidizing substance, 2 were solvents, and 9 were miscellaneous substances. There were 21 ocular exposures, 8 cutaneous exposures, 4 mixed (ocular/cutaneous), and 1 oral exposure. Initial clinical findings in ocular exposures were: pain, blepharospasm, hyperemia, palpebral edema, excessive tearing, and blurred vision. Of cutaneous exposures, 1 was a deep necrotic injury and 7 were superficial. Median (IQR) VAS before flushing with Diphoterine® was 7; VAS after ocular or skin flushing was 1. Conclusion: Early application of the amphoteric solution to the eye or skin reduces the intensity of pain associated with chemical injury. While randomized clinical trials are lacking, early use of the amphoteric solution appears to reduce the incidence of sequelae.

Toxic Epidermal Necrolysis and Acute Kidney Injury due to Glyphosate Ingestion

The literature, particularly from India, is scarce on the renal effects of glyphosate poisoning. Glyphosate causes toxicity not only after its ingestion but also after dermal exposure by inhalation route and on eye exposure. We present a patient report of glyphosate consumption which resulted in toxic epidermal necrolysis – the first report after glyphosate consumption and acute kidney injury.

Use of an Amphoteric Solution in Eye, Skin and Oral Chemical Exposures: Retrospective Multicenter Clinical Case Series

Use of an Amphoteric Solution in Eye, Skin and Oral Chemical Exposures: Retrospective Multicenter Clinical Case Series

Eyewash Stations in Teaching and Research Laboratories Host Potential Pathogenic Microbiota

Background According to current safety regulations, teaching and research laboratories require one or more eyewash stations installed in case of eye exposure to harmful substances. The presence of potential pathogens on these devices may increase risk of infection when used. Thus, we have conducted a research project to evaluate the microbiota of the eye washers present in several buildings across Michigan State University’s campus. Our data showed that 90% of the surveyed eyewash stations on campus are heavily contaminated with bacteria and fungi. Thus, their use in cases of eye injury could be a matter of public health concern.Methods 40 labs from different departments equipped with eye washers were visited and samples were taken from each of them. Sterile swabs and contact mycology plates were used to collect samples. The right side of the eyewash was designated for bacterial sampling and the left for fungal sampling. Two Blood agar plates were used for each bacterial sample collection. Both plates were incubated for 5 days at 25°C and 37°C respectively. Mycology plates were used for fungal collection, and these were incubated at 25°C. Following incubation, cultures were observed using microscopy and the number of colonies were counted. Plates were determined to have heavy contamination if the number of colonies were too many to count, and low contamination if few or no colonies were grown. Gram staining was performed for bacterial cultures, and additional biochemical tests were done to identify taxonomy of bacteria. Classification of fungal colonies was determined based on colony morphology.ResultsHeavy contamination was discovered on 90% of interrogated eye washers, while the other 10% showed low to no growth at 37°C and 25°C. Gram-positive rods were the most abundant bacteria present in all tested units at 37°C. At 25°C, the most abundant bacteria were Gram-negative rods. 21 strains with high diversity were found on Mycology plates – Aspergillus, Fusarium, Mucor, Cladosporium, and Penicillium.Conclusion The presence of potentially pathogenic microbiota on eyewashers may pose a threat to the user, given that the nature of use is linked to eye injury. In future studies, sequencing will be necessary in identifying bacteria and fungi, in order to more accurately match them with know pathogenic species.Disclosures All authors: No reported disclosures.

Quantification of Temperature Rise within the Lens of the Porcine Eye Caused by Ultrasound Insonation

The soft tissue thermal index defined in the Output Display Standard is not applicable to eye exposures because of unique eye properties such as high ultrasound absorption in the lens and orbital fat. To address this potential safety issue, the U.S. Food and Drug Administration has recommended a maximum exposure level for ophthalmic exams of 50 mW/cm2 (derated spatial-peak temporal-average intensity, ISPTA.3) based on a model of ultrasound propagation in the eye. To gain a better understanding of actual temperature rise as a function of ISPTA.3, an ex vivo experimental study within the porcine lens was performed. Both temperature and acoustic pressure were measured simultaneously in the lens using a fiberoptic probe. At ISPTA.3 = 50 mW/cm2, the maximum and average temperature rises over 133 measurements were 0.23°C and 0.09°C, respectively. A 1.5°C temperature rise was not obtained until ISPTA.3 ≈ 435 mW/cm2. The data indicate that operating below the Food and Drug Administration guidance level should result in relatively low heating in ophthalmic exposures.

Quality and safety management

The optical radiation emitted by lasers has the potential to damage the eyes and skin of patients and healthcare workers such as nurses, clinicians and medical technicians. Laser related accidents resulting in blindness and deaths have been reported. The EU directive 2006/25/EC “Control of Artificial Optical Radiation at work Regulations” aims to protect workers from the risk stated above by limiting the exposure levels to both eye and skin. Medical Physics departments in most hospitals are responsible for managing the safe use of lasers. A Laser Protection Advisor (similar to Radiation Protection Advisor) is responsible for implementing the safety control mechanisms, training staff on laser safety and investigating any adverse events when either patient or staff are injured. This talk will cover the quality and safety management of laser use. Delegates are advised to attend the topic on “Basic Physics and Technology of Medical Lasers” as a prerequisite. Basic principles of risk assessment, maximum permissible exposure (MPE) levels and laser classification are explained. Methods to keep exposure of unprotected skin and eyes below the MPE levels are demonstrated. Hazard control procedures such as controlled area access, written safe operating procedures, warning signs and lights, authorised use of equipment and the use of personal protection are explained. Principles and requirements of equipment quality assurance processes and procedures to maintain the quality of safety are demonstrated. Relevant legislations and standards are covered in this talk.

Equivalence between solar irradiance and solar simulators in aging tests of sunglasses.

BackgroundThis work is part of a broader research that focuses on ocular health. Three outlines are the basis of the pyramid that comprehend the research as a whole: authors’ previous work, which has provided the public to self-check their own sunglasses regarding the ultraviolet protection compatible to their category; Brazilian national survey in order to improve nationalization of sunglasses standards; and studies conducted on revisiting requirements of worldwide sunglasses standards, in which this work is inserted. It is still controversial on the literature the ultraviolet (UV) radiation effects on the ocular media, but the World Health Organization has established safe limits on the exposure of eyes to UV radiation based on the studies reported in literature. Sunglasses play an important role in providing safety, and their lenses should provide adequate UV filters. Regarding UV protection for ocular media, the resistance-to-irradiance test for sunglasses under many national standards requires irradiating lenses for 50 uninterrupted hours with a 450 W solar simulator. This artificial aging test may provide a corresponding evaluation of exposure to the sun.MethodsCalculating the direct and diffuse solar irradiance at a vertical surface and the corresponding radiant exposure for the entire year, we compare the latter with the 50-h radiant exposure of a 450 W xenon arc lamp from a solar simulator required by national standards.ResultsOur calculations indicate that this stress test is ineffective in its present form.ConclusionsWe provide evidence of the need to re-evaluate the parameters of the tests to establish appropriate safe limits for UV irradiance.SignificanceThis work is potentially significant for scientists and legislators in the field of sunglasses standards to improve the requirements of sunglasses quality and safety.

The influence of operator position, height and body orientation on eye lens dose in interventional radiology and cardiology: Monte Carlo simulations versus realistic clinical measurements

ObjectiveThis paper aims to provide some practical recommendations to reduce eye lens dose for workers exposed to X-rays in interventional cardiology and radiology and also to propose an eye lens correction factor when lead glasses are used. MethodsMonte Carlo simulations are used to study the variation of eye lens exposure with operator position, height and body orientation with respect to the patient and the X-ray tube. The paper also looks into the efficiency of wraparound lead glasses using simulations. Computation results are compared with experimental measurements performed in Spanish hospitals using eye lens dosemeters as well as with data from available literature. ResultsSimulations showed that left eye exposure is generally higher than the right eye, when the operator stands on the right side of the patient. Operator height can induce a strong dose decrease by up to a factor of 2 for the left eye for 10-cm-taller operators. Body rotation of the operator away from the tube by 45°–60° reduces eye exposure by a factor of 2. The calculation-based correction factor of 0.3 for wraparound type lead glasses was found to agree reasonably well with experimental data. ConclusionsSimple precautions, such as the positioning of the image screen away from the X-ray source, lead to a significant reduction of the eye lens dose. Measurements and simulations performed in this work also show that a general eye lens correction factor of 0.5 can be used when lead glasses are worn regardless of operator position, height and body orientation.

Knowledge, attitude and behaviour regarding hepatitis C virus infection amongst Brazilian dental students

Dental health professionals, including dental students, are at high risk of exposure to infection with the hepatitis C virus (HCV) through occupational percutaneous injuries and eye exposure. Further, fear of HCV infection is associated with discriminatory attitudes. The current study aimed to evaluate the knowledge about HCV infection amongst dental students and their attitudes towards patients infected with HCV. A cross-sectional survey was conducted amongst 340 Brazilian dental students from two public universities using an instrument containing information regarding demographic characteristics, knowledge of HCV and attitudes towards patients with HCV infection. Descriptive statistics, Fisher's exact test, Student's t-tests, Mann-Whitney U-test and multiple logistic regression (MLR) were carried out (P < 0.05 was considered significant). Response rate was 90% (n = 306), and more than half (54%, n = 165) of participants had high knowledge level (above the mean); 97.7% (n = 299) demonstrated positive attitudes. MLR showed that high knowledge of dental students regarding HCV was substantially influenced by advancement in year of study (last year; P < 0.001) and type of university (federal; P = 0.049). Positive attitude towards HCV-infected patients was mainly influenced by age (P = 0.004) and male gender (P = 0.022). These results demonstrated a satisfactory knowledge about HCV infection amongst dental students, but some gaps were observed, suggesting the importance of continuous education about HCV in this population to prevent HCV infection as well as discrimination and prejudice towards patients with hepatitis C.

754 exposures to reed diffusers reported to the United Kingdom National Poisons Information Service 2010–2014

Objective: The objective of this study is to review the reported toxicity of reed diffuser fragrance liquid which, in addition to essential oils, commonly contains glycol ethers but other ingredients and/or alternatives are 3-methoxy-3-methyl-1-butanol, petroleum distillates, ethanol and isopropanol. Methods: We analysed retrospectively enquiries to the United Kingdom National Poisons Information Service between 1 January 2010 and 31 December 2014. Results: 754 patients were exposed to reed diffusers; the majority (n = 712) were children < 5 years. Ingestion was the most common route of exposure (706 of 754 patients) and involved the liquid alone (n = 570), water beads alone (n = 84), sucking on the reeds (n = 31) or ingesting the liquid and water beads (n = 21). The reported amount of fragrance liquid ingested was known in only 76 of 591 cases (12.9%), with a median (IQR) volume of 20.0 (IQR = 10–40) mL. The WHO/IPCS/EC/EAPCCT Poisoning Severity Score (PSS) was known in 702 of 706 sole ingestions: in 574 (81.3%), the PSS was 0 (asymptomatic); in 117 (16.6%) patients, the PSS was 1 (minor toxicity); in 11 (1.6%), the PSS was 2 (moderate toxicity); there were no patients with features graded PSS 3 (severe toxicity). Significantly (p = 0.008) more patients became symptomatic (PSS 1 and PSS 2) following the ingestion of a reed diffuser containing 3-methoxy-3-methyl-1-butanol than propylene glycol monobutyl ether, though there was no significant difference when compared with those containing dipropylene glycol monomethyl ether (p = 0.181). The most common features following ingestion of fragrance liquid were nausea and vomiting (n = 53), coughing (n = 17) and CNS depression (n = 9). Seven patients suffered eye exposure alone: two developed eye pain and four conjunctivitis. Dermal exposure alone was reported in six patients, two of whom developed skin irritation. Conclusions: The majority of patients in our study developed no features or only minor symptoms following ingestion of reed diffuser fragrance liquid.

Radiation Exposure During Fluoro-Assisted Direct Anterior Total Hip Arthroplasty

BackgroundUtilization of the direct anterior approach (DAA) for total hip arthroplasty (THA) has increased in the last decade with fluoroscopy often used to confirm implant position, leg length, and offset. Radiation exposure thresholds around 800 mGy are published for the risk of cataracts. We hypothesized that surgeon eye exposure during fluoro-assisted DAA total hip arthroplasty would be well below these published thresholds. MethodsThree experienced orthopedic surgeons performed 30 consecutive fluoro-assisted DAA THAs. During each procedure, the surgeon wore a helmet-mounted dosimeter. After 30 consecutive cases, the dosimeters were analyzed. A chart review was then completed to obtain fluoroscopic data saved for each individual case including fluoroscopic time, total radiation dose, and radiation tech experience. ResultsFluoroscopic data were available for 89 of 90 cases (98.8%). Surgeon 1 had an average fluoroscopic time of 18.51 seconds, radiation dose of 2.396 mGy, and tech experience of 13.06 years. Surgeon 2 had an average fluoroscopic time of 15.63 seconds, radiation dose of 2.139 mGy, and tech experience of 23.69 years. Surgeon 3 had an average fluoroscopic time of 11.06 seconds, radiation dose of 1.462 mGy, and tech experience of 16.03 years. The dosimeter results were 8, 5, and <1 mrem, respectively, for each surgeon. The mean total radiation dose per case for all surgeons was 2.00 mGy (±1.31), and there was no correlation between radiation dose and radiologic tech experience (0.089, P > .05) or radiation dose and patients' body mass index (0.260, P = .014). ConclusionsEach surgeon would need to perform >300,000 DAA THAs to exceed the 800-mGy cataract threshold dose. The decision to wear protective glasses should be at the surgeon's discretion; however, the findings in this study show a very low radiation dose to the surgeon's eye regardless of radiologic tech experience or patient's body mass index.

Low-energy light bulbs, computers, tablets and the blue light hazard.

The introduction of low energy lighting and the widespread use of computer and mobile technologies have changed the exposure of human eyes to light. Occasional claims that the light sources with emissions containing blue light may cause eye damage raise concerns in the media. The aim of the study was to determine if it was appropriate to issue advice on the public health concerns. A number of sources were assessed and the exposure conditions were compared with international exposure limits, and the exposure likely to be received from staring at a blue sky. None of the sources assessed approached the exposure limits, even for extended viewing times.

Protective Effect of Fucoxanthin Isolated from Laminaria japonica against Visible Light-Induced Retinal Damage Both in Vitro and in Vivo.

With increasingly serious eye exposure to light stresses, such as light-emitting diodes, computers, and widescreen mobile phones, efficient natural compounds for preventing visible light-induced retinal damages are becoming compelling needs in the modern society. Fucoxanthin, as the main light absorption system in marine algae, may possess an outstanding bioactivity in vision protection because of its filtration of blue light and excellent antioxidative activity. In this work, both in vitro and in vivo simulated visible light-induced retinal damage models were employed. The in vitro results revealed that fucoxanthin exhibited better bioactivities than lutein, zeaxanthin, and blueberry anthocyanins in inhibiting overexpression of vascular endothelial growth factor, resisting senescence, improving phagocytic function, and clearing intracellular reactive oxygen species in retinal pigment epithelium cells. The in vivo experiment also confirmed the superiority of fucoxanthin than lutein in protecting retina against photoinduced damage. This excellent bioactivity may be attributed to its unique structural features, including allenic, epoxide, and acetyl groups. Fucoxanthin is expected to be an important ocular nutrient in the future.

Assess the practice regarding safety measures used by nurses while handling Chemotherapy drugs

Background : In a recent study of outpatient nurses, participants reported significant unintended skin and eye exposure to chemotherapy (Friese, et al., 2011). In this study, the author concludes that the overall rate of exposure decreases when nurses report adequate staffing and resources (2011). This implies that nurse-patient ratios and workplace demands contribute to the problem of mishandling chemotherapy. Therefore, these results implicate the need for adequate staffing and resources as well as increased staff compliance to established practice standards in order to better protect oncology nurses. Other contributing factors identified in system failures that result in an unsafe work environment include lack of awareness of personal and public risks of exposure, poor communication, and direct interruptions and/or distractions while preparing to administer medications (Ashley, et al., 2011). Objectives : To assess the practice regarding safety measures used by nurses while handling chemotherapy drugs. Method : In this Study the structured checklist was used to see the practice regarding safety measures used by nurses while handling chemotherapy drugs. Result : Assessment of nurses practice while handling chemotherapy drug shows that Majority of samples 56 (56%) were having poor practice while handling chemotherapy drugs and 44% of nurses were having good practice while handling chemotherapy drugs, Maximum score was 6 and minimum score was 1. Conclusion : After the detailed analysis, this study leads to the following conclusion that assessment of nurses' practice while handling chemotherapy drug. Majority of samples were having poor practice while handling chemotherapy drugs.

Three‐dimensional structure of the mammalian limbal stem cell niche

PurposeAlthough the existence of the limbal stem cell (LSC) niche is accepted, precise knowledge of its 3D architecture remains incomplete.MethodsThe LSC niche was explored on freshly excised corneoscleral rims from human donors (n = 47), pigs (n = 15) and mice (n = 27) with full‐field optical coherence microscopy (FFOCM).ResultsLimbal crypt features were detected in 90% of human corneoscleral rims, extending between the palisades of Vogt as radial (74%) and/or rounded (23%) forms, often branching off to or becoming interconnected by sub‐scleral radially or circumferentially oriented crypts (56%). [kg1] Mean crypt volume represented 16% of sampled limbal volume on the vertical axis and 8% on the horizontal axis. In pigs, palisades were finer and crypts wider with relatively uniform distribution around the eye, and radial orientation, connecting to numerous narrow criss‐crossing invaginations beneath the sclera. In mice, only a circumferential limbal trough was detected. Mean crypt volume represented 13% of limbal volume in humans, 9% in pigs and 7% in mice. FFOCM combined with fluorescence showed presence of p63‐α+ cells and cytokeratin‐3 + cells in the limbal crypts. LSC density increased with percentage limbal volume occupied by crypts. Colony Forming Efficiency increased with limbal crypt volume. [kg1] See how to rephrase all this.ConclusionsCrypt architecture in the three species appears associated with eye exposure to light. Clone production correlated strongly with the limbal crypt volume in humans indicating that limbal crypts constitute a niche for adult limbal stem cells. FFOCM imaging could assist in assessment of the richness of the limbal crypts and targeted biopsy for cell culture.

Simulations of Porcine Eye Exposure to Primary Blast Insult.

A computational model of the porcine eye was developed to simulate primary blast exposure. This model facilitates understanding of blast-induced injury mechanisms. A computational model of the porcine eye was used to simulate the effects of primary blast loading for comparison with experimental findings from shock tube experiments. The eye model was exposed to overpressure-time histories measured during physical experiments. Deformations and mechanical stresses within various ocular tissues were then examined for correlation with pathological findings in the experiments. Stresses and strains experienced in the eye during a primary blast event increase as the severity of the blast exposure increases. Peak stresses in the model occurred in locations in which damage was most often observed in the physical experiments. Blast injuries to the anterior chamber may be due to inertial displacement of the lens and ciliary body while posterior damage may arise due to contrecoup interactions of the vitreous and retina. Correlation of modeling predictions with physical experiments lends confidence that the model accurately represents the conditions found in the physical experiments. This computational model offers insights into the mechanisms of ocular injuries arising due to primary blast and may be used to simulate the effects of new protective eyewear designs.