Irreversible Eye Damage Research Articles

Glaucoma Disease Classification by using Fundus images

Optic Disc (OD) and Optic Cup (OC) damage is caused by the eye condition glaucoma. OD is the morphological structure that is apparent in the cross-sectional view of the optic nerve connecting to the retina, while OC is the core region of OD. The morphological changes in the optic disc (OD) and optic cup (OC) often happen before visual field issues when glaucoma begins. Optic nerve head damage caused by glaucoma is permanent. Glaucoma is the greatest global cause of irreversible blindness, according to data from the World Health Organization (WHO). Only 10 to 50 percent of glaucoma patients, according to population-level surveys, are aware that they have the condition. As a result, glaucoma early identification is crucial for preventing irreversible eye damage. Glaucoma is a vision disorder that frequently affects older people and renders them permanently blind. Glaucoma affects 2.5% of people of all ages and 4.8% of people over the age of 75. Using MobileNetV2, this study suggests a unique deep transfer learning model for categorizing glaucoma. With regard to the error, with the least amount of expense, MobileNetV2 is a framework that optimizes memory consumption and execution speed. To increase the dataset and MobileNetV2's precision, data augmentation techniques were used. Using the HRF dataset, the suggested deep learning model's effectiveness is assessed. Results from the suggested procedure are accurate to 98%. Medical professionals can find the optimum course of treatment for their patients with the help of automated glaucoma classification.

Development of an Eye Irritation Test Method Using an In-House Fabrication of a Reconstructed Human Cornea-like Epithelium Model for Eye Hazard Identification.

In a previous study, a novel human corneal-like epithelium model utilizing an immortalized human corneal epithelial cell line (iHCE-NY1) was developed as an alternative to animal models to identify chemicals not classified under the United Nations Globally Harmonized System of Classification and Labeling of Chemicals (GHS) and was evaluated following the criteria of Test Guideline 492 of the Organization for Economic Co-operation and Development (OECD). In the present study, our aim was to establish an eye irritation test protocol using the iHCE-NY1 model to classify liquid chemicals under the GHS ocular hazard categories: no effect, no classification (No Cat.), Category 2 (Cat. 2) reversible effects, and Category 1 (Cat. 1) irreversible eye damage. The protocol involved exposing the iHCE-NY1 model to 31 liquid test chemicals for 5 min, followed by observation at post-incubation periods (PIPs) to assess recovery. Classification was based on cell viability, and histopathological findings on PIP days 7, 14, and 21. The outcomes were compared with an established database of classifications. All Cat. 1 liquid chemicals, 62.5% of No Cat., and 63.2% of Cat. 2 were correctly categorized. This study demonstrates that the iHCE-NY1 model can not only distinguish No Cat. test liquid chemicals but also differentiate between Cat. 2 and Cat. 1 liquid chemicals.

Image preprocessing‐based ensemble deep learning classification of diabetic retinopathy

AbstractDiabetic retinopathy (DR) can cause irreversible eye damage, even blindness. The prognosis improves with early diagnosis. According to the International Classification of Diabetic Retinopathy Severity Scale (ICDRSS), DR has five stages. Modern, cost‐effective techniques for automatic DR screening and staging of fundus images are based on deep learning (DL). To obtain higher classification accuracy, the combination of several diverse individual DL models into one ensemble could be used. A new approach to model diversity in an ensemble is proposed by manipulating the training input data involving original and four variants of preprocessed image datasets. There are publicly available datasets with labels for all five stages, but some contain poor‐quality images. In contrast, this algorithm was trained on images from a six‐class DDR dataset, including the class of poor‐quality ungradable images, to enhance the classification performance. The solution was evaluated on the APTOS dataset, containing only ICDRSS classes. Classification results of the ensemble model were presented on two different ensemble convolutional neural network (CNN) models, based on Xception and EfficientNetB4 architectures using two fusion approaches. Our proposed ensemble models outperformed all other single deep learning architectures regarding overall accuracy and Cohen's Kappa, with the best results using the EfficientNetB4 architecture.

Predicting the Safety of Ocular Iontophoresis Using Reconstructed Human Corneal Epithelial Cells.

We aimed to investigate eye damage caused by ocular iontophoresis (IP) based on an in vitro eye irritation test using a reconstructed human corneal cell. In this study, the LabCyte CORNEA-MODEL was selected as the reconstructed corneal cell. The test procedure was performed according to Test Guideline No.492 of the Organisation for Economic Co-operation and Development, which was partially revised for the IP. From the relationship between the cell viability of the cornea model and the electric field intensity [current density (mA/cm2) × application time (min)] of the IP, we predicted that the intensity values of 465 mA/cm2 × min and 930 mA/cm2 × min caused reversible eye irritation and irreversible eye damage, respectively. However, further studies are required to improve the accuracy and reproducibility of the prediction. This report provides essential knowledge on the clinical safety of ocular IP.

Type IV hypersensitivity to timolol

Type IV hypersensitivity to timolol

Glaucoma and Diabetes: A Sweet Connection

Background/Objective: 
 Glaucoma is the leading cause of irreversible blindness in the world. In the United States alone, a little more than three million people live with this disorder which is caused by damage to the optic nerve found in the back of the eye. This is most commonly caused by an increase in the intraocular pressure, or the fluid that maintains the shape and provides nutrients to the eye. Diabetes mellitus (DM), an age-related disorder, is a risk factor for glaucoma. Post-meal, the sugar one eats is managed in the body by the hormone insulin. However, the excess sugar found in diabetics, can exhaust the production of insulin and lead to many adverse complications in the body as well as increase risk of disease. Although some studies suggest a correlation between diabetes and glaucoma, the mechanisms of this association has not been thoroughly investigated. Our objective is to further explore this connection and provide the mechanisms that link diabetes to glaucoma. 
 
 Results: 
 From retrospective literature review, we find that diabetes is known to have an additive effect on neural apoptosis and in the generation of reactive oxygen in patients with high intraocular pressure. DM also impairs retrograde axonal transport, causes an accumulation of fibronectin in trabecular meshwork, changes eye vasculature, causes dysregulation in lipid metabolism, and malabsorption of vitamins. 
 
 
 Conclusion & Scientific/Clinical Policy Impact and Implications: 
 This study sheds light on one of the most troubling eye conditions worldwide. The symptoms of diabetes described here increase ones’ risk of developing glaucoma. These pathways result in obstruction of aqueous humor drainage or direct damage to the optic nerve cells leading to glaucoma. Diabetes is a common disease that involves many body systems. With knowledge of the relationship between diabetes and glaucoma, measures can be taken to prevent irreversible eye damage in the diabetic population.

Survey of Youth Awareness Regarding Toxic Alcohol (Methanol) and HOOCH Tragedies

The term Toxic alcohol include as a proper name Methanol, and is applied both to the absolute substance further specified by chemists as methyl alcohol, and to its mixtures with smaller proportions of water and slight proportions of other substances. In chemistry, the word alcohol is used as a common or generic name to designate several series of substances containing Ethanol in different percentages. Alcohol consumption has existed in India for many centuries. The quantity of toxicity problem has undergone substantial changes over the past twenty years. In India many deaths are related to intake of toxic alcohol. These are liquors made in India under government license and the maximum Ethanol content allowed is 42.8%. Besides licensed distilleries, a number of small production units operate clandestinely. The toxic alcohol is industrial methylated sprits which regularly cause mass toxicity to humans, who lose their lives or suffer irreversible eye damage and overdose of methanol is death results in this research survey showed that maximum youth are not aware about the toxic alcohols. There is an urgent need to make people aware about methanol toxicity.

MAGAM II – prospective observational multicentre poisons centres study on eye exposures caused by cleaning products

Objective: Local effects on the eye following cleaning product exposures are frequently reported. According to EU chemicals legislation many cleaning products are labelled with Hazard Phrase 318 indicating risk of irreversible eye damage. The objectives of this study were to identify cleaning products with potential for irreversible eye damage by collecting human exposure data from poisons centres (PC), and to clarify to what degree exact product identification is possible during a PC telephone call.Methods: MAGAM II was a multicentre binational prospective observational PC study. All human eye exposures to detergents or maintenance products reported to nine PCs taking calls from the public and medical professionals during an 18-month period were included. The severity of eye effects was rated according to the WHO Poisoning Severity Score.Results: Five hundred and eighty-six cases were included. Product identification by name leading to formula information was successful in 533 cases (91%). Follow-up was successful in 528 exposures. Irrigation was performed in 94% of cases. Duration of symptoms was ≥24 hours in 73 patients (25%). 33 (6%) patients developed moderate eye injury. Healing was reported in all cases. The percentage of moderate cases was highest in the group of drain cleaners (25%), toilet cleaners (18%) and oven cleaners (15%). Products intended for professional use caused relatively more moderate eye injuries than products also intended for consumer use.Conclusion: MAGAM II has shown that PCs are able to identify formulas in sufficiently high quality as needed for product-directed toxicovigilance. The results underline the potential of PC exposure case data for product safety monitoring. The results indicate that irreversible eye damage is very rare after cleaning product exposure.

Eye irritation potential: palm-based methyl ester sulphonates

Aim: To evaluate eye irritation potential of palm-based methyl ester sulphonates (MES) of different chain lengths; C12, C14, C16, C16:18.Methods: The Bovine Corneal Opacity and Permeability test method (BCOP), OECD Test Guideline 437, was used as an initial step to study the inducing effect of palm-based MES on irreversible eye damage. The second assessment involved the use of reconstructed human corneal-like epithelium test method, OECD Test Guideline 492 using SkinEthic™ Human Corneal Epithelium to study the potential effect of palm-based MES on eye irritancy. The palm-based MES were prepared in 10% solution (w/v) in deionized water and tested as a liquid and surfactant test substances whereby both test conducted according to the liquid/surfactant treatment protocol.Results: The preliminary BCOP results showed that palm-based MES; C12, C14, C16, C16:18 were not classified as severe eye irritants test substances with in vitro irritancy score between 3 and the threshold level of 55. The second evaluation using SkinEthic™ HCE model showed that palm-based MES; C12, C14, C16, C16:18 and three commercial samples were potentially irritants to the eyes with mean tissue viability ≤ 60% and classified as Category 2 according to United Nations Globally Harmonized System of Classification and Labelling of Chemicals. However, there are some limitations of the proposed ocular irritation classification of palm-based MES due to insolubility of long chain MES in 10% solution (w/v) in deionized water.Conclusion: Therefore, future studies to clarify the eye irritation potential of the palm-based MES will be needed, and could include; methods to improve the test substance solubility, use of test protocol for solids, and/or inclusion of a benchmark anionic surfactant, such as sodium dodecyl sulphate within the study design.

Glucocorticoid therapy and ocular hypertension

The projected number of people who will develop age-related macular degeneration in estimated at 2020 is 196 million and is expected to reach 288 million in 2040. Also, the number of people with Diabetic retinopathy will grow from 126.6 million in 2010 to 191.0 million by 2030. In addition, it is estimated that there are 2.3 million people suffering from uveitis worldwide. Because of the anti-inflammatory properties of glucocorticoids (GCs), they are often used topically and/or intravitreally to treat ocular inflammation conditions or edema associated with macular degeneration and diabetic retinopathy. Unfortunately, ocular GC therapy can lead to severe side effects. Serious and sometimes irreversible eye damage can occur as a result of the development of GC-induced ocular hypertension causing secondary open-angle glaucoma. According to the world health organization, glaucoma is the second leading cause of blindness in the world and it is estimated that 80 million will suffer from glaucoma by 2020. In the current review, mechanisms of GC-induced damage in ocular tissue, GC-resistance, and enhancing GC therapy will be discussed.

Methodology to Assess Potential Glint and Glare Hazards From Concentrating Solar Power Plants: Analytical Models and Experimental Validation

With a growing number of concentrating solar power systems being designed and developed, the potential impact of glint and glare from concentrating solar collectors and receivers is receiving increased attention as a potential hazard or as a distraction for motorists, pilots, and pedestrians. This paper provides analytical methods to evaluate the irradiance originating from specularly and diffusely reflecting sources as a function of distance and characteristics of the source. Sample problems are provided for both specular and diffuse sources, and validation of the models is performed via testing. In addition, a summary of safety metrics is compiled from the literature to evaluate the potential hazards of calculated irradiances from glint and glare for short-term exposures. Previous safety metrics have focused on prevention of permanent eye damage (e.g., retinal burn). New metrics used in this paper account for temporary after-image, which can occur at irradiance values several orders of magnitude lower than the irradiance values required for irreversible eye damage.

Novel cultured porcine corneal irritancy assay with reversibility endpoint

Several alternative assays exist to assess ocular irritancy without the use of live animals. However, these assays cannot address ocular injury reversibility. Reversibility is an issue critical to regulatory authorities and manufactures of commercial products, as ocular irritation caused by misuse or accidental exposure to a product may cause irreversible eye damage. Here we report the development and initial characterization of a novel ocular irritation assay that addresses ocular injury reversibility. This assay, the Porcine Corneal Ocular Reversibility Assay (PorCORA), uses an air-interface porcine corneal culture system to sustain ex vivo porcine corneas as a model system. These corneas are maintained in culture for 21 days to determine if cornea injury, once inflicted, will reverse. Corneal injury reversibility is measured using Sodium Fluorescein (NaFl) stain to detect compromised epithelial barrier function. In this study, we examined the effects of five compounds on the cultured corneas: phosphate-buffered saline (PBS), 100% Ethanol (EtOH), 3% Sodium Dodecyl Sulfate (SDS), 1% Benzalkonium Chloride (BAK), and 10% Sodium Hydroxide (NaOH). Overall, the persistence of corneal effects between historical Draize rabbit eye data and PorCORA indicates a correlation coefficient of 0.98 (for the five compounds tested) and a correlation coefficient of 0.97 with the Draize modified maximal average score (MMAS). Finally, both fluorescence confocal microscopy and histopathology evidence demonstrates that the PorCORA and NaFl measurements are indicative of actual cellular and tissue damage. PorCORA shows promise as a potential non-animal replacement assay capable of predicting ocular damage reversibility.

Mine timber economies

The toxicology of hydrogen sulfide (H2S) and sour gas on the eye has a long history beginning at least with Ramazzini's observations [Ramazzini B. Diseases of Workers—De Morbis Artificum Diatriba—1713. Wright WC (trans). New York, C. Hafner Publishing Co Inc.; 1964. 98–99 pp.]. In contrast, a recent review by Alberta Health and Wellness (AHW Report) concluded that there is little evidence of eye irritation following short-term exposures to H2S at concentrations up to 100 ppm and that the H2S literature on the eye is a series of unsubstantiated claims reproduced in review articles dating back to the 1930s [Alberta Health and Wellness (AHW report). Health effects associated with short-term exposure to low levels of hydrogen sulfide: a technical review, Alberta Health and Wellness, October 2002, 81pp.]. In this paper, we evaluated this claim through a historical review of the toxicology of the eye. Ramazzini noted the effects of sewer gas on the eye [Ramazzini B. Diseases of Workers—De Morbis Artificum Diatriba—1713. Wright WC (trans). New York, C. Hafner Publishing Co Inc. 1964. 98–99 pp.]. Lehmann experimentally showed eye effects in men at 70–90 ppm H2S and also in animals [Lehmann K. Experimentalle Studien uber den Einfluss technisch und hygienisch wichtiger Gase und Dampfe auf den Organismus. Arch Hyg 1892;14:135–189]. In 1923, Sayers, Mitchell and Yant reported eye effects in animals and men at 50 ppm H2S. Barthelemy showed eye effects in animals and men at 20 ppm H2S [Barthelemy HL. Ten years' experience with industrial hygiene in connection with the manufacture of viscose rayon. J Ind Hyg Toxicol 1939;21:141–51]. Masure experimentally showed that H2S is the causative agent of eye impacts in animals and men [Masure R. La Keratoconjunctivite des filatures de viscose; etude clinique and experiementale. Rev Belge Pathol 1950;20:297–341]. Michal upon microscopic examination of the rat's cornea, found nuclear pyknosis, edema and separation of cells in the eye following exposures for 3 h at 36 ppm H2S [Michal FV. Eye lesions caused by hydrogen sulfide. Cesk Ophthalmol 1950;6;5–8]. In 1975, in Alberta, irreversible eye damage and photophobia were experimentally produced in calves exposed to 20 ppm H2S for 1 week [Nordstrom GA. A study of calf response of ammonia and hydrogen sulfide gases. Thesis, University of Alberta, Department of Agricultural Engineering, Edmonton Alberta; 1975, 218 pp.]. Alberta Environmental Centre documented clinical irritation of the eye at 40 ppm H2S in 6 hours in rats [Alberta Environmental Centre. Morphological observations in rats exposed for six hours to an atmosphere of 0, 56, or 420 mg/m3 hydrogen sulfide. AECV86-A1. Alberta Environmental Centre, Vegreville, Alberta; 1986b. 28 pp.]. In two sour gas blow-outs in Alberta, in the early 1980s, eye injury was documented in humans and animals at 0.5 ppm H2S. Community studies in the United States, Europe and New Zealand suggest that acute exposure to 25 ppb H2S is the lowest concentration to irritate the eyes; with chronic exposure, serious eye effects are suggested. In contrast to the conclusion, all of the studies, except one, cited in the AHW Report indicate toxic effects on the eye below 100 ppm H2S [Alberta Health and Wellness (AHW report). Health effects associated with short-term exposure to low levels of hydrogen sulfide (H2S): a technical review, Alberta Health and Wellness, October 2002, 81pp.]. In addition, the AHW Report (2002) mis-presented two studies as ‘clinical studies’, claiming they reported no evidence of eye effects in humans from 2 and 30 ppm H2S for 30–40 minutes [Alberta Health and Wellness (AHW report). Health effects associated with short-term exposure to low levels of hydrogen sulfide (H2S): a technical review, Alberta Health and Wellness, October 2002, 81pp.].

Physiological effects of exposure to low concentrations of carbon monoxide

The toxicology of hydrogen sulfide (H2S) and sour gas on the eye has a long history beginning at least with Ramazzini's observations [Ramazzini B. Diseases of Workers—De Morbis Artificum Diatriba—1713. Wright WC (trans). New York, C. Hafner Publishing Co Inc.; 1964. 98–99 pp.]. In contrast, a recent review by Alberta Health and Wellness (AHW Report) concluded that there is little evidence of eye irritation following short-term exposures to H2S at concentrations up to 100 ppm and that the H2S literature on the eye is a series of unsubstantiated claims reproduced in review articles dating back to the 1930s [Alberta Health and Wellness (AHW report). Health effects associated with short-term exposure to low levels of hydrogen sulfide: a technical review, Alberta Health and Wellness, October 2002, 81pp.]. In this paper, we evaluated this claim through a historical review of the toxicology of the eye. Ramazzini noted the effects of sewer gas on the eye [Ramazzini B. Diseases of Workers—De Morbis Artificum Diatriba—1713. Wright WC (trans). New York, C. Hafner Publishing Co Inc. 1964. 98–99 pp.]. Lehmann experimentally showed eye effects in men at 70–90 ppm H2S and also in animals [Lehmann K. Experimentalle Studien uber den Einfluss technisch und hygienisch wichtiger Gase und Dampfe auf den Organismus. Arch Hyg 1892;14:135–189]. In 1923, Sayers, Mitchell and Yant reported eye effects in animals and men at 50 ppm H2S. Barthelemy showed eye effects in animals and men at 20 ppm H2S [Barthelemy HL. Ten years' experience with industrial hygiene in connection with the manufacture of viscose rayon. J Ind Hyg Toxicol 1939;21:141–51]. Masure experimentally showed that H2S is the causative agent of eye impacts in animals and men [Masure R. La Keratoconjunctivite des filatures de viscose; etude clinique and experiementale. Rev Belge Pathol 1950;20:297–341]. Michal upon microscopic examination of the rat's cornea, found nuclear pyknosis, edema and separation of cells in the eye following exposures for 3 h at 36 ppm H2S [Michal FV. Eye lesions caused by hydrogen sulfide. Cesk Ophthalmol 1950;6;5–8]. In 1975, in Alberta, irreversible eye damage and photophobia were experimentally produced in calves exposed to 20 ppm H2S for 1 week [Nordstrom GA. A study of calf response of ammonia and hydrogen sulfide gases. Thesis, University of Alberta, Department of Agricultural Engineering, Edmonton Alberta; 1975, 218 pp.]. Alberta Environmental Centre documented clinical irritation of the eye at 40 ppm H2S in 6 hours in rats [Alberta Environmental Centre. Morphological observations in rats exposed for six hours to an atmosphere of 0, 56, or 420 mg/m3 hydrogen sulfide. AECV86-A1. Alberta Environmental Centre, Vegreville, Alberta; 1986b. 28 pp.]. In two sour gas blow-outs in Alberta, in the early 1980s, eye injury was documented in humans and animals at 0.5 ppm H2S. Community studies in the United States, Europe and New Zealand suggest that acute exposure to 25 ppb H2S is the lowest concentration to irritate the eyes; with chronic exposure, serious eye effects are suggested. In contrast to the conclusion, all of the studies, except one, cited in the AHW Report indicate toxic effects on the eye below 100 ppm H2S [Alberta Health and Wellness (AHW report). Health effects associated with short-term exposure to low levels of hydrogen sulfide (H2S): a technical review, Alberta Health and Wellness, October 2002, 81pp.]. In addition, the AHW Report (2002) mis-presented two studies as ‘clinical studies’, claiming they reported no evidence of eye effects in humans from 2 and 30 ppm H2S for 30–40 minutes [Alberta Health and Wellness (AHW report). Health effects associated with short-term exposure to low levels of hydrogen sulfide (H2S): a technical review, Alberta Health and Wellness, October 2002, 81pp.].