Cataract Induction Research Articles

Lens Fragmentation with Picosecond Laser Pulses After Artificial Cataract Induction with Microwaves.

Objectives: In this work we demonstrate the first laboratory study results of lens fragmentation with low-energy picosecond ultrashort laser pulses after artificial induction of cataract with microwave radiation on an ex vivo animal model. Background: This method will be evaluated with regard to the further development of lens fragmentation with novel ultrashort picosecond laser systems instead of ultrasonic phacoemulsification or the significantly more complex femtosecond laser fragmentation. Methods: As samples we used postmortem porcine eyes. The lenses were dissected and then irradiated in a microwave oven for artificial cataract induction. Subsequent computer-driven lens fragmentation was performed with a 12 ps, 1064 nm pulsed laser source with 100 µJ pulse energy, and 10 kHz pulse repetition rate. Results: Both the artificial cataract induction and the lens fragmentation were demonstrated. When inducing cataract, different degrees/stages of opaqueness and hardness could be achieved with different irradiation times and methods. The fragmentation with 12 ps pulses led to good results with regard to ablation depth and rate, especially for the softer lenses. Conclusions: As could be shown, low-energy picosecond ultrashort laser pulses are feasible for cataractous lens fragmentation on an ex vivo animal model with artificial cataract induction. Thus, this technique may influence future cataract surgeries by possibly being an alternative or extension to state-of-the-art methods. This will be evaluated with further tests and studies.

N-Acetylcysteine amide (NACA) and diNACA inhibit H2O2-induced cataract formation ex vivo in pig and rat lenses

Oxidative stress plays a central role in cataract formation suggesting that antioxidants might slow cataract progression. The anticataract activity of N-acetylcysteine amide (NACA) and (2 R, 2 Rʼ)-3,3ʼ-disulfanediyl bis(2-acetamidopropanamide) (diNACA) and/or N-acetylcysteine (NAC), were evaluated in porcine and rat lens models. Cataractogenesis via oxidation was induced with H2O2 and/or glucose oxidase (GO). Porcine lenses were incubated in 0.1 mM, 1 mM, or 10 mM NAC, NACA or diNACA for 24 h. Lenses were then transferred to media containing 0.75 mM H2O2 and 4.63U of GO in order to maintain a constant H2O2 level for an additional 8 h. At the end of incubation, lenses were imaged under darkfield microscopy. Separately, rat lenses were extracted from 3-week-old Wistar rats and incubated with either 10 mM NACA or 10 mM diNACA for 24 h prior to treatment with 0.2U GO to generate a steady source of ∼0.6 mM H2O2. Rat lenses were analyzed by LC-MS/MS to quantify changes in cysteine, cystine, glutathione (GSH) or oxidised glutathione (GSSG) levels in the lens epithelium, cortex or core. Pre-treatment with NACA or diNACA followed by oxidation with H2O2 and/or GO to stimulate cataract formation afforded rapid assessment in ex vivo porcine (32 h) and rat (48 h) lens models. Pre-treatment of isolated porcine lenses with 0.1 mM, 1 mM or 10 mM of either NAC, NACA or diNACA followed by H2O2/GO treatment resulted in reduced lens opacity relative to the lenses exposed to H2O2/GO, with NACA and diNACA reducing opacities to a greater extent than NAC. Rat lenses incubated with 10 mM NACA or 10 mM diNACA without exposure to H2O2 showed no signs of opacities. Pre-treatment of rat lenses with 10 mM NACA or 10 mM diNACA, followed by GO cataract induction resulted in reduced opacities compared to control (GO alone). LC-MS/MS analyses revealed that NACA, but not diNACA, increased cysteine, cystine and GSH levels in rat lens epithelium and cortex regions. Taken together, both NACA and diNACA inhibited cataract formation to a greater extent than NAC (all at 1–10 mM) in an ex vivo porcine lens model. Both NACA and diNACA (both at 10 mM) reduced cataract formation in rat lenses. Based on LC-MS/MS analyses, NACA-induced reduction in opacity observed in rat lenses was attributed to enhanced cysteine and GSH levels while the diNACA-induced reduction in opacity induced did not consistently increase cysteine, cystine and GSH levels and, therefore, appears to involve a different antioxidant mechanism. These screening studies warrant further testing of NACA and diNACA as anticataract agents.

Primary treatment of malignant retinal detachment caused by choroidal breast cancer metastasis using only systemic chemotherapy and anti-HER-2 therapy

Introduction: Choroidal metastasis is a disabling complication of several types of common cancer, including breast cancer. Metastases to the choroid may present insidiously but ultimately cause significant visual disturbance and more rarely may result in retinal detachment, causing sudden and profound visual impairment. The usual treatment of choice for choroidal metastases is palliative radiotherapy. External beam radiotherapy to the posterior orbit is often effective in stabilizing and improving the symptoms but it can usually be given only once and carries the risk of cataract induction as a side effect. Case Report: Here we report using only systemic therapy [chemotherapy and initial dual anti-human epidermal growth factor receptor-2 (HER-2) therapy] to treat a 69-year-old female presenting with newly diagnosed widespread secondary breast cancer, a major symptom of which was visual disturbance related to exudative retinal detachment caused by choroidal metastases. The systemic therapy treated the choroidal metastases effectively and allowed the retinal detachment to improve quickly, and the positive effect of the systemic anti-cancer therapy could be observed directly by serial ophthalmological examination over the first two months of the cancer treatment, allowing earlier detection of treatment response than would normally be seen on routine radiological scanning. Conclusion: We propose that in selected cases systemic therapy alone may be sufficient initial treatment for choroidal metastases from cancers that are expected to show a marked and relatively rapid response to systemic therapy, such as HER-2-positive breast cancer, allowing radiotherapy to be kept in reserve for further treatment of malignant lesions in the choroid in the future.

Роль соматической патологии в индукции сенильной катаракты

Введение. Соматические заболевания у лиц с сенильной катарактой приводят к метаболическим и структурным нарушениям разной локализации и степени выраженности. Цель исследования. Провести анализ коморбидного состояния у лиц с сенильной катарактой. Материалы и методы. Ретроспективно проведен анализ амбулаторных карт и историй болезни 173 пациентов независимой выборки с диагнозом «сенильная катаракта», поступивших на плановое стационарное хирургическое лечение в ГАУЗ «Кузбасская областная клиническая больница им. С.В. Беляева» г. Кемерово в 2017–2021 гг. Из выборки исключены пациенты с осложненной, травматической и врожденной катарактой. Учитывались как анамнестические данные, так и данные соматического состояния пациентов на момент операции. Оценка проведена по декадам жизни человека: моложе 40 лет, 41–50 лет, 51–60 лет, 61–70 лет, 71–80 лет и старше 80 лет. Для расчета индекса коморбидности использовали методику Charlson. Результаты. Оценка коморбидного статуса пациентов проведена в два этапа. На первом этапе изучены характер и частота соматических заболеваний в группах по декадам жизни. На втором этапе анализ сопутствующей общей соматической патологии проведен с учетом совокупности заболеваний у каждого пациента (индивидуальный индекс коморбидности) и в целом в группе по декадам жизни (групповой индекс коморбидности) с помощью методики Charlson. Выводы. 1. Наибольший прирост индекса коморбидности соматической патологии отмечен в декаде 51–60 лет у лиц с сенильной катарактой. 2. Среди сопутствующих соматических заболеваний превалировали: заболевания сердечно-сосудистойсистемы – 129 (74,6%); нарушение углеводного обмена – 35 (20,2%); заболевания центральной нервной системы – 33 (19,1%), опорно-двигательного аппарата – 30 (17,3%), дыхательной системы – 19 (11,0%). Introduction. Somatic diseases of individuals with senile cataract lead to metabolic and structural disorders of different localization and severity. Purpose of the study. To analyze the comorbid condition in individuals with senile cataract. Materials and methods. A retrospective analysis of outpatient charts and case histories of 173 patients of an independent sample with a diagnosis of "senile cataract" admitted for planned inpatient surgical treatment at the "Kuzbass Regional Clinical Hospital named after S.V. Belaev", Kemerovo, in 2017–2021. Patients with complicated, traumatic and congenital cataract were excluded from the sample. Both the data of the somatic state of patients at the time of the operation, and transferred in the anamnesis, were taken into the account. The assessment was carried out by decades of human life: younger than 40 years old, 41–50 years old, 51–60 years old, 61–70 years old, 71–80 years old and over 80 years old. The comorbidity index was calculated using the Charlson method. Results. The assessment of the comorbid background of patients carried out in two stages. At the first stage, the nature and frequency of somatic diseases in the groups by decades of life were studied. At the second stage, the analysis of co-morbid general somatic pathology was carried out taking into account the totality of diseases of each patient (individual comorbidity index), and in the group by decades of life overall (group comorbidity index) using the Charlson technique. Conclusions. 1. The greatest increase in the comorbidity index of somatic pathology was found in the 51–60 years decade in persons with senile cataract. 2. Among comorbid somatic diseases the following prevailed: cardiovascular diseases – 129 (74.6%); carbohydrate metabolism disorders – 35 (20.2%); central nervous system diseases – 33 (19.1%); musculoskeletal system – 30 (17.3%); respiratory system – 19 (11.0%).

Spectrofluorimetric changes in the lens after intravitreal injections of brolucizumab

The study evaluates the changes in spectrofluorometric parameters of the lens after intravitreal injections of brolucizumab in eyes with native lens. The study included 13 people with neovascular age-related macular degeneration (AMD) who received IVI of brolucizumab. All patients were over 40 years old; changes in central retinal thickness in the macular area exceeded 300 μm according to optical coherence tomography. Spectrofluorimetric indicators of the lens were studied before and after injections of the drug in both eyes. The spectra were analyzed in the wavelength range 412-698 nm to record the changes in the content of non-tryptophan fluorophore molecules in the lens. Spectrofluorimetry revealed metabolic changes in the native lens after intravitreal injections of the drug brolucizumab. No such changes were observed in the lens of the eyes not injected with the drug (the «Control» group). The proposed investigation technique involves prospective assessment of the safety of various molecules injected intravitreally in terms of cataract development at various times after the injection. Spectrofluorimetry can be used for identifying initial metabolic changes in the lens. It is a promising method for assessing the molecules used in intravitreal injections in terms of their safety for the native lens, as well as for development of detailed instructions for clinically substantiated use of drugs with adverse effects in the form of cataract induction. According to spectrofluorimetry, IVI of the drug brolucizumab affects metabolic changes in the lens.

Патогенетические аспекты катарактогенеза с позиции коморбидной патологии

Relevance. Research by ophthalmologists, biologists, biochemists, biophysicists, physiologists have shown the significance of xeno- and endobiotic effects on the induction of cataracts and other degenerative diseases of the structures and membranes of the eye. Objective research goal was an evaluation of comorbid background in people of different ages with a diagnosis of senile cataract. Material and methods an analysis of the case histories of 173 patients of an independent sample with a diagnosis of "senile cataract" admitted for planned inpatient surgical treatment was carried out. The evaluation was carried out by decades of human life: younger than 40 years old, 41–50 years old, 51–60 years old, 61–70 years old, 71–80 years old and over 80 years old. The Charlson method was used to calculate the comorbidity index. Results patients who had senile cataract and concomitant somatic diseases, the most frequent- diseases of the cardiovascular system – 129 (74.6 %); violation of carbohydrate metabolism – 35 (20.2 %); diseases of the central nervous system – 33 (19.1 %); musculoskeletal system – 30 (17.3 %); diseases of the respiratory system – 19 (11.0 %). Conclusions. 1. A human's age of 51–60 years should be considered critical for the occurrence of senile cataract. 2. In the decade of life 51–60 years, there is an increase in persons with senile cataract by 3.3 and the frequency of concomitant somatic pathology (according to the index of comorbidity) by 2.25. Keywords: senile cataract, age, somatic diseases, index of comorbidity

Protective Effects of Piceatannol against Selenite-Induced Cataract and Oxidative Damage in Rats

Purpose This study aimed to investigate the protective effects of piceatannol (PIC) on selenite-induced cataracts in Sprague-Dawley rats and explore its therapeutic effects as an antioxidant. Methods Thirty-two eight-day-old rat pups were randomly divided into four groups, with eight pups in each of them. Group 1, as the control group, was injected with the same amount of saline, while Groups 2–4 were administered with sodium selenite (3.46 mg/kg) subcutaneously into the neck on postpartum day 10 for cataract induction. Without further treatment, Group 2 served as the control model, while Groups 3 and 4 (low- and high-dose PIC-treated) had intraperitoneal piceatannol from day 8 to day 17 at doses of 10 mg/kg and 20 mg/kg, respectively. On postpartum day 17, after the last injection, the rat pups were examined for cataract grade by slit lamp, and the lenses of every group were isolated for oxidative damage indicators and further analysis. SRA01/04 cells were exposed to 600 μM H2O2 for 24 hours with or without pretreatment with 10μМ piceatannol. Cell viability was tested by CCK-8 assay and cell apoptosis was evaluated by AnnexinV-PE/7AAD assay. Results This study determined that compared with the model group, the degree of lens opacity was significantly reduced in PIC-treated groups. The histopathological damage of the lenses in the PIC-treated groups improved compared to the model group. There were fewer signs of lesions, such as vacuoles and atrophy. The biochemical results indicated that malondialdehyde (MDA) content of the PIC-treated groups were downregulated and the antioxidant enzyme activities (GSH and catalase) and antioxidant status (SOD) were upregulated compared with the model group. In vitro, piceatannol significantly restored cell viability and cell apoptosis under H2O2 injury. Conclusion Pretreatment with piceatannol may achieve a protective effect on cataract development through upregulating antioxidant enzyme activity.

Assessment of Organ and Effective Doses Received by Paediatric Patients Undergoing Computed Tomography Examinations in Three Hospitals in Brazzaville, Congo Republic: An Urgent Necessity for Regulatory Control

The present study aimed at estimating organ and effective doses from computed tomography (CT) scans of paediatric patients in three hospitals in Brazzaville, Congo Republic. A total of 136 data on paediatric patients, from 0.25 (3 months) to 15 years old, who underwent head, chest, abdomen – pelvis (AP) and chest – abdomen – pelvis (CAP) CT scans was considered. The approach followed in the present study to compute organ doses was to use pre-calculated volume CT dose index (CTDIvol) – and 100 milliampere-second (mAs) – normalized organ doses determined by Monte Carlo (MC) simulation. Effective dose were then derived using the international commission on radiological protection (ICRP) publications 60 and 103 formalism. For comparison purposes, effective dose were also computed using dose-length product (DLP) – to – effective dose conversion factors. A relatively high variation in organ and effective doses was observed in each age group due to the dependence of patient dose on the practice of technicians who perform the CT scan within the same facility or from one facility to another, patient size and lack of adequate training of technicians. In the particular case of head scan, the brain and the eye lens were delivered maximum absorbed doses of 991.81 mGy and 1176.51 mGy, respectively (age group 10-15 y). The maximum absorbed dose determined for the red bone marrow was 246.08 mGy (age group 1-5 y). This is of concern as leukaemia and brain tumours are the most common childhood cancers and as the ICRP recommended absorbed dose threshold for induction of cataract is largely exceeded. Effective doses derived from MC calculations and ICRP publications 60 and 103 tissues weighting factors showed a 0.40-17.61 % difference while the difference between effective doses derived by the use of k- factors and those obtained by MC calculations ranges from 0.06 to 224.87 %. The study has shown that urgent steps should be taken in order to significantly reduce doses to paediatric patients to levels observed in countries where dose reduction techniques are successfully applied.

RADIATION DOSE TO THE EYE AND POTENTIAL OCCURRENCE RADIATION- INDUCED CATARACT FOLLOWING COMPUTED TOMOGRAPHY (CT) HEAD EXAMINATION


 
 
 The eye is a radiosensitive organ that lies within the scan range during Computed Tomography (CT) of the head. The utilization of the head CT is increasing with growing concern about the chances of development of cataract which induces by ionising radiation. This research aimed to calculate eye absorbed dose and to study the potential occurrence of radiation induces cataracts between CT Brain and CT Temporal. A total of 399 set data were obtained retrospectively according to inclusion and exclusion criteria. 364 patients underwent CT Brain while 35 patients’ data obtained for CT Temporal. The scanning parameters such as tube current, tube potential, pitch factor, beamwidth, filter, revolution time, and filter were recorded. Eye absorbed dose was significantly different (p<0.05) between CT brain (49.07±10.08mGy) and CT temporal (25.72 ± 6.12mGy). None of the analysed data exceeded the eye threshold dose recommended by ICRP 2012. However, as expected, the cumulative eye absorbed dose was increased as the frequencies of the scan increase. The highest number of repeated scans is five times with cumulative dose was recorded as 278.27mGy. In conclusion, the eye absorbed dose is higher in CT Brain compared to CT Temporal and has potential for induction of cataract in the future especially with the patient that undergoes repeated CT examination.
 
 

Ultraviolet Radiation Environment of a Tropical Megacity in Transition: Mexico City 2000-2019.

Tropical regions experience naturally high levels of UV radiation, but urban pollution can reduce these levels substantially. We analyzed 20 years of measurements of the UV index (UVI) at several ground-level locations in the Mexico City Metropolitan Area and compared these data with the UVI values derived from the satellite observations of ozone and clouds (but not local pollution). The ground-based measurements were systematically lower than the satellite-based estimates by ca. 40% in 2000 and 25% in 2019. Calculations with a radiative transfer model using observed concentrations of air pollutants explained well the difference between satellite and ground-based UVI and showed specific contributions from aerosols, O3, NO2, and SO2 in decreasing order of importance. Such large changes in UV radiation between 2000 and 2019 have important implications ranging from human health (skin cancer and cataract induction) to air pollution control (photochemical smog formation).

Early Responses to Low-Dose Ionizing Radiation in Cellular Lens Epithelial Models.

Cataract is the leading cause of visual impairment which can result in blindness. Cataract formation has been associated with radiation exposure; however, the mechanistic understanding of this phenomenon is still lacking. The goal of this study was to investigate mechanisms of cataract induction in isolated lens epithelial cells (LEC) exposed to ionizing radiation. Human LECs from different genetic backgrounds (SV40 immortalized HLE-B3 and primary HLEC cells) were exposed to varying doses of 137Cs gamma rays (0, 0.1, 0.25 and 0.5 Gy), at low (0.065 Gy/min) and higher (0.3 Gy/min) dose rates. Different assays were used to measure LEC response for, e.g., viability, oxidative stress, DNA damage studies, senescence and changes to telomere length/telomerase activity at two time points (1 h and 24 h, or 24 h and 15 days, depending on the type of assay and expected response time). The viability of cells decreased in a dose-dependent manner within 24 h of irradiation. Measurement of reactive oxygen species showed an increase at 1 h postirradiation, which was alleviated within 24 h. This was consistent with DNA damage results showing high DNA damage after 1 h postirradiation which reduced significantly (but not completely) within 24 h. Induction of senescence was also observed 15 days postirradiation, but this was not attributed to telomere erosion or telomerase activity reduction. Overall, these findings provide a mechanistic understanding of low-dose radiation-induced cataractogenesis which will ultimately help to inform judgements on the magnitude of risk and improve existing radiation protection procedures.

Protective Effects of Safranal Against Selenite-Induced Cataract in Rats

Cataract, which is the opacity inside clear ocular lens of eye, result in the scattering of visible light as it passes via the lens and consequently deterioration in optical image. The aim of the present study was to investigate whether safranal, an active constituent of Crocus sativus L. stigmas, has a protective effect on the cataract in the rat's pups. The animals were randomly divided into five groups, each of which consisted of 7 rat pups. Group I served as normal control (vehicle administration). For testing cataract induction, animals of Groups II, III, and IV were administered a single subcutaneous injection of sodium selenite on postpartum day 12. After sodium selenite intoxication, Group II served as control selenite, Groups III-IV received intraperitoneal safranal at doses of 200, and 300 mg/kg, respectively from the 11th day through the 17th day, while group V receive only safranal (300 mg/kg). On postpartum day 30, the rat pups were examined for cataract formation, and the lenses were isolated for further analysis. This study found that selenite caused significant (p < 0.05) cataract formation. Through the effects of selenite on the level of lipid peroxidation (MDA) which was upregulated. Furthermore, the antioxidant enzymes levels GSH levels and NRF2 protein were downregulated. In contrast, treatment with safranal could significantly (p < 0.05) ameliorate cataract formation and oxidative damage in the lens. Moreover, safranl administration significantly increased the protein expressions of Nrf2 and the GSH level, in addition to reducing the level both the MDA and the level soluble proteins in the lens. Taken together, safranal is a prospective anti-cataract agent that probably delays the onset and progression of cataracts induced by sodium selenite.

Contribution of Genetic Background to the Radiation Risk for Cancer and Non-Cancer Diseases in Ptch1+/- Mice.

Experimental mouse studies are important to gain a comprehensive, quantitative and mechanistic understanding of the biological factors that modify individual risk of radiation-induced health effects, including age at exposure, dose, dose rate, organ/tissue specificity and genetic factors. In this study, neonatal Ptch1+/- mice bred on CD1 and C57Bl/6 background received whole-body irradiation at postnatal day 2. This time point represents a critical phase in the development of the eye lens, cerebellum and dentate gyrus (DG), when they are also particularly susceptible to radiation effects. Irradiation was performed with γ rays (60Co) at doses of 0.5, 1 and 2 Gy, delivered at 0.3 Gy/min or 0.063 Gy/min. Wild-type and mutant mice were monitored for survival, lens opacity, medulloblastoma (MB) and neurogenesis defects. We identified an inverse genetic background-driven relationship between the radiosensitivity to induction of lens opacity and MB and that to neurogenesis deficit in Ptch1+/- mutants. In fact, high incidence of radiation-induced cataract and MB were observed in Ptch1+/-/CD1 mutants that instead showed no consequence of radiation exposure on neurogenesis. On the contrary, no induction of radiogenic cataract and MB was reported in Ptch1+/-/C57Bl/6 mice that were instead susceptible to induction of neurogenesis defects. Compared to Ptch1+/-/CD1, the cerebellum of Ptch1+/-/C57Bl/6 mice showed increased radiosensitivity to apoptosis, suggesting that differences in processing radiation-induced DNA damage may underlie the opposite strain-related radiosensitivity to cancer and non-cancer pathologies. Altogether, our results showed lack of dose-rate-related effects and marked influence of genetic background on the radiosensitivity of Ptch1+/-mice, supporting a major contribution of individual sensitivity to radiation risk in the population.

Evaluating Dose-response of Cataract Induction in Radiotherapy of Head and Neck Cancers Patients.

Background: Head and neck cancers are currently the most common types of cancers. 3D-conformal radiation therapy is the most common dose delivery technique for head and neck cancers. Eye Lens is a radio sensitive structure and cataract formation as a visual disorder associated with exposure to ionizing radiation which is documented. Objective: Determining the radiation dose to eye lens during head and neck radiography and estimating the probability of cataract induction are essential.Material and Methods: This experimental study was performed on 14 patients with head and neck cancers through experimental study analysis. The maximum opacity of the eyes lens were measured by pentacamTM before radiation therapy. CT data of patients were transmitted to Isogray treatment planning Software, and dose calculations for each patient was performed. At the end of radiation treatment, 3 and 6 months after radiotherapy, the eye lens opacity of the patients was assessed.Results: Overall, 28 lenses were studied. Statistical one sample K- S test proved normality of obtained data. Using repeated measures test, the relation before and 3 months after radiotherapy, as well as the relationship before and 6 months after radiotherapy proved a significant relationship.Conclusion: The opacity caused by radiation in eyes is a non-statistical and linear-quadratic response curve with no threshold. This opacity can also appear within 3 months after completion of radiation therapy.

Eye Lens Doses Received by Radiation Workers in Interventional Medical Procedures

The International Commission on Radiological Protection (ICRP) has recently recommended that the occupational dose limit for the eye lens be reduced to 20 mSv per year, averaged over defined periods of 5 years, with no single year exceeding 50 mSv. ICRP clearly states that the recommendations are chiefly based on epidemiological evidence that suggested the eye lens dose threshold for cataract induction revised downwards from 2-5 Gy to about 0.5 Gy. Interventional medical workers are at greater health risk from radiation exposure to eyes as a result of the procedures they undertake than most other medical specialists. An extensive study has been carried out to measure the eye lens doses received by 373 interventional medical radiation workers in twelve large hospitals in Indonesia. Measurements were made using Thermo Scientific Harshaw thermoluminescence dosimeter (TLD) chip (size 3.2 mm × 3.2 mm × 0.15 mm) put inside an EYE-D holder placed in the worker’s temple. The procedures performed are grouped based on classification made by the UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation). The results showed that in general the measured data are in an agreement with some published data, even though a large range of doses was observed. The highest mean eye lens dose of 0.2378 mSv per procedure was received by interventionists who worked in the abdominal interventions procedure. Overall, from the results of measurement, it can be concluded that most interventionists might receive eye lens dose exceeding the dose limit if the procedures are carried out on daily basis, and the abdominal interventions procedures were found to be the ones that give the highest risk to the eye lens of workers as it delivered the highest dose to this particular organ. 14.00 Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";}

RETRACTED ARTICLE: Role of short-wavelength blue light in the formation of cataracts and the expression of caspase-1, caspase-11, Gasdermin D in rat lens epithelial cells: insights into a novel pathogenic mechanism of cataracts

BackgroundWith the popularity of blue-rich light-emitting diode (LED)-backlit display devices, our eyes are now exposed to more short-wavelength blue light than they were in the past. The goal of this study was to investigate the pathogenesis of cataracts after short-wavelength light exposure.MethodsSprague-Dawley (SD) rats were selected and randomly divided into a control group (10 rats each for the 4-, 8-, and 12-week groups) and an experimental group (10 rats each for the 4-, 8-, and 12-week groups). The rats in the experimental group were exposed to a short-wavelength blue LED lamp for 12 h per day. After exposure to the blue LED lamp, the rats were maintained in total darkness for 12 h, after which a 12-h light/dark cycle was resumed. The intensity of the lamp was 3000 lx. At the end of the short-wavelength blue LED lamp exposure (for 4, 8, and 12 weeks), the expression levels of caspase-1, caspase-11 and gasdermin D (GSDMD) were examined in rat lens epithelial cells (LECs) using qRT-PCR and Western blot analyses. An illuminance of 2500 lx was used to study the potential effect of blue LED light on HLE-B3 hLECs in vitro. AC-YVAD-CMK, a caspase-1 inhibitor, was used to confirm the pyroptosis of LECs by flow cytometry.ResultsAfter 6 weeks, cataracts developed in the experimental rats (4/20 eyes). The clarity of the lens gradually worsened with the duration of exposure. Twelve weeks later, all of the rat eyes had developed cataracts. The expression levels of caspase-1, caspase-11 and GSDMD at 4, 8, and 12 weeks were significantly higher in the samples from rats exposed to a short-wavelength blue LED lamp than in the samples from control rats (p<0.05). The proportions of double-positive hLECs were significantly increased in the 5-h and 10-h short-wavelength blue light exposure subgroups compared with the 5-h and 10-h caspase-1 inhibitor subgroups (p < 0.05).ConclusionThe data indicate that pyroptosis plays a key role in cataract induction after short-wavelength blue light exposure. This study might provide new insights into a novel pathogenic mechanism of cataracts.

Comparison of intravitreal dexamethasone implant and anti-VEGF drugs in the treatment of retinal vein occlusion-induced oedema: a meta-analysis and systematic review

ObjectiveTo compare the efficacy and safety of intravitreal dexamethasone (DEX) implant and anti-vascularendothelial growth factor (anti-VEGF) agents in the treatment of macular oedema secondary to retinal vein occlusion (RVO).DesignSystematic review...

ELECTRON EYE-LENS OPERATIONAL DOSE COEFFICIENTS.

In 2012, the International Commission on Radiological Protection issued a recommendation for a reduced annual eye-lens dose limit in the face of mounting evidence of the risk of cataract induction. This led to worldwide research efforts in various areas including the dose simulation in realistic eye-models, the production of dosimeters and the elaboration of protection and operation fluence to eye-lens dose coefficients. In this last case, much efforts have been expanded with regards to photon operational coefficients for Hp (3) but much less for electron radiation. In this work, Hp (3) coefficients for electrons are presented following simulations using MCNP and compared to those that are available in the literature. It is found that, at energies of 1MeV and less, Hp (3) coefficients depend strongly on the selected electron transport options and on the dose tally volume. The effect of these differences is demonstrated for two beta emitters.

Aggregation of β-crystallin through covalent binding to 1,2-naphthoquinone is rescued by α-crystallin chaperone.

Cataract induced by exposure to naphthalene is thought to mainly involve its metabolic activation, forming 1,2-naphthoquinone (1,2-NQ), which can modify proteins through chemical modifications. In the present study, we examined the effect of 1,2-NQ on aggregation of crystallins (cry) associated with cataract. Incubation of bovine β-cry with 1,2-NQ caused covalent modification of β-cry at Cys117 and Lys125 accompanied by reduction in its thiol content, resulting in a concentration- and temperature-dependent aggregation of β-cry, whereas only little aggregation of α-cry induced by 1,2-NQ was seen. Interestingly, addition of α-cry to the reaction mixture of β-cry and 1,2-NQ markedly blocked β-cry aggregation induced by 1,2-NQ in a concentration-dependent manner. These results suggest that β-cry predominantly undergoes chemical modification by 1,2-NQ, causing its aggregation, which is suppressed by the chaperone-like protein, α-cry. This β-cry aggregation may be, at least in part, involved in the induction of cataract caused by 1,2-NQ.

Risk of cataract in health care workers exposed to ionizing radiation: A systematic review

Background:The eye is an important sensory organ occupationally exposed to ionizing radiation (IR) in healthcare workers (HCWs) engaged in medical imaging (MI). New evidence highlights the possible induction of cataract at IR exposure levels to be much lower than expected in the past.Objective:Conduct an updated review on the current evidence on cataract risk in healthcare workers exposed to IR.Methods:Published scientific studies on cataract risk in IR exposed healthcare workers were collected through a systematic search of two biomedical databases (MEDLINE and Scopus). Data from included studies was extracted and summarized. Study quality was also assessed.Results:All 21 eligible studies reported an increased prevalence of cataract, especially posterior subcapsular cataract, in IR exposed HCWs with a higher prevalence in interventional cardiology staff.Discussion:Our review synthesizes the latest evidence to support the hypothesis of a significantly increased risk of occupational cataract in healthcare workers operating MI and exposed to IR, especially in interventional cardiologists. Data also support a dose-response relationship between IR exposure and the prevalence of opacities, especially posterior subcapsular opacities.Conclusions:Findings highlight the need for effective control measures including appropriate training, adherence to protective procedures, and a constant use of shields and eye personal protective equipment in healthcare workers with optical exposure to IR. Periodic health surveillance programs, possibly including lens evaluation, are also important to monitor cataract risk in these MI operators.