Radiation Cataract

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Per G Soderberg - One of the best experts on this subject based on the ideXlab platform.

  • temperature controlled in vivo ocular exposure to 1090 nm Radiation suggests that near infrared Radiation Cataract is thermally induced
    Journal of Biomedical Optics, 2015
    Co-Authors: Karl Schulmeister, Nooshin Talebizadeh, Martin Kronschlager, Per G Soderberg
    Abstract:

    The damage mechanism for near-infrared Radiation (IRR) induced Cataract is unclear. Both a photochemical and a thermal mechanism were suggested. The current paper aims to elucidate a photochemical effect based on investigation of irradiance-exposure time reciprocity. Groups of 20 rats were unilaterally exposed to 96-W/cm2 IRR at 1090 nm within the dilated pupil accumulating 57, 103, 198, and 344  kJ/cm2, respectively. Temperature was recorded at the limbus of the exposed eye. Seven days after exposure, the lenses were macroscopically imaged and light scattering was quantitatively measured. The average maximum temperature increases for exposure times of 10, 18, 33, and 60 min were expressed as 7.0±1.1, 6.8±1.1, 7.6±1.3, and 7.4±1.1°C [CI (0.95)] at the limbus of the exposed eye. The difference of light scattering in the lenses between exposed and contralateral not-exposed eyes was 0.00±0.02, 0.01±0.03, −0.01±0.02, and −0.01±0.03 transformed equivalent diazepam concentration (tEDC), respectively, and no apparent morphological changes in the lens were observed. An exposure to 96-W/cm2 1090-nm IRR projected on the cornea within the dilated pupil accumulating radiant exposures up to 344  kJ/cm2 does not induce Cataract if the temperature rise at the limbus is <8°C. This is consistent with a thermal damage mechanism for IRR-induced Cataract.

  • impact of iris pigment and pupil size in ultraviolet Radiation Cataract in rat
    Acta Ophthalmologica, 2012
    Co-Authors: S Lofgren, Ralph Michael, Per G Soderberg
    Abstract:

    . Purpose:  To investigate the effect of iris pigment and pupil size in ultraviolet Radiation (UVR)-induced Cataract. Methods:  Brown-Norway rats (pigmented) and Fischer-344 rats (non-pigmented) were unilaterally exposed in vivo to 5 kJ/m2 UVR. Each strain was split into two groups, each receiving either mydriatic (tropicamide) or miotic (pilocarpine) eye-drops. One week after exposure, the degree of ocular inflammation and damage in the anterior segment was determined. The lenses were extracted, photographed and the degree of forward light scattering (Cataract) was quantified. Results:  The Cataract types differed between the two strains. All Fischer rats developed macroscopically identifiable UVR Cataract while only 41% of Brown-Norway rats did so. All groups except the miotic Brown-Norway developed significant light scattering. The Fischer rats developed 3–4-fold more lens light scattering than the Brown-Norway rats. The miotic Fischer group exhibited significantly more light scattering than the mydriatic Fischer group. There was no significant difference in light scattering between the two Brown-Norway groups. There was a correlation between ocular inflammation and degree of light scattering, with Brown-Norway rats exhibiting less inflammation and lens light scattering. Conclusions:  Pigmented rats develop less UVR Cataract and less ocular inflammation than non-pigmented rats. Pupil size plays a smaller role in UVR Cataract development in pigmented rats than in non-pigmented. The role of UVR-induced ocular inflammation in Cataract development is still ambiguous.

  • impact of age and sex in ultraviolet Radiation Cataract in the rat
    Investigative Ophthalmology & Visual Science, 2003
    Co-Authors: S Lofgren, Ralph Michael, Per G Soderberg
    Abstract:

    PURPOSE. The purpose of this study was to determine the influence of age and sex on the development of ultraviolet Radiation (UVR) Cataract in rats. Current safety limits for lens damage due to UVR do not consider age or sex. METHODS. Four age groups of Sprague-Dawley rats (3, 6, 17, and 52 weeks) were exposed to 300-nm UVR at either 5 or 8 kJ/m 2 , delivered during 15 minutes. The interval between irRadiation and Cataract assessment was 1 or 8 weeks. Moreover, two groups of 6-week-old male and female rats were exposed to 5 kJ/m 2 UVR, with Cataract assessment after 1 week. The severity of Cataract was quantified by measurement of forward light-scattering in isolated lenses. RESULTS. The youngest age group showed development of anterior subcapsular, equatorial, and nuclear Cataract, whereas the three older groups exhibited the first two types. The two younger age groups had significantly more Cataract than the other groups. The degree of Cataract increased from 1 to 8 weeks after irRadiation. There was no difference in Cataract severity between sexes. CONCLUSIONS. Young rats are more sensitive to UVR than old rats. Nuclear UVR Cataract develops in young rats but not in adult rats. With the chosen waveband and dose, the time for maximum Cataract development to occur is longer than 1 week. There is no difference in UVR sensitivity between the sexes.

S Lofgren - One of the best experts on this subject based on the ideXlab platform.

  • solar ultraviolet Radiation Cataract
    Experimental Eye Research, 2017
    Co-Authors: S Lofgren
    Abstract:

    Despite being a treatable disease, Cataract is still the leading cause for blindness in the world. Solar ultraviolet Radiation is epidemiologically linked to Cataract development, while animal and in vitro studies prove a causal relationship. However, the pathogenetic pathways for the disease are not fully understood and there is still no perfect model for human age related Cataract. This non-comprehensive overview focus on recent developments regarding effects of solar UV Radiation wavebands on the lens. A smaller number of fundamental papers are also included to provide a backdrop for the overview. Future studies are expected to further clarify the cellular and subcellular mechanisms for UV Radiation-induced Cataract and especially the isolated or combined temporal and spatial effects of UVA and UVB in the pathogenesis of human Cataract. Regardless of the cause for Cataract, there is a need for advances in pharmaceutical or other treatment modalities that do not require surgical replacement of the lens.

  • impact of iris pigment and pupil size in ultraviolet Radiation Cataract in rat
    Acta Ophthalmologica, 2012
    Co-Authors: S Lofgren, Ralph Michael, Per G Soderberg
    Abstract:

    . Purpose:  To investigate the effect of iris pigment and pupil size in ultraviolet Radiation (UVR)-induced Cataract. Methods:  Brown-Norway rats (pigmented) and Fischer-344 rats (non-pigmented) were unilaterally exposed in vivo to 5 kJ/m2 UVR. Each strain was split into two groups, each receiving either mydriatic (tropicamide) or miotic (pilocarpine) eye-drops. One week after exposure, the degree of ocular inflammation and damage in the anterior segment was determined. The lenses were extracted, photographed and the degree of forward light scattering (Cataract) was quantified. Results:  The Cataract types differed between the two strains. All Fischer rats developed macroscopically identifiable UVR Cataract while only 41% of Brown-Norway rats did so. All groups except the miotic Brown-Norway developed significant light scattering. The Fischer rats developed 3–4-fold more lens light scattering than the Brown-Norway rats. The miotic Fischer group exhibited significantly more light scattering than the mydriatic Fischer group. There was no significant difference in light scattering between the two Brown-Norway groups. There was a correlation between ocular inflammation and degree of light scattering, with Brown-Norway rats exhibiting less inflammation and lens light scattering. Conclusions:  Pigmented rats develop less UVR Cataract and less ocular inflammation than non-pigmented rats. Pupil size plays a smaller role in UVR Cataract development in pigmented rats than in non-pigmented. The role of UVR-induced ocular inflammation in Cataract development is still ambiguous.

  • impact of age and sex in ultraviolet Radiation Cataract in the rat
    Investigative Ophthalmology & Visual Science, 2003
    Co-Authors: S Lofgren, Ralph Michael, Per G Soderberg
    Abstract:

    PURPOSE. The purpose of this study was to determine the influence of age and sex on the development of ultraviolet Radiation (UVR) Cataract in rats. Current safety limits for lens damage due to UVR do not consider age or sex. METHODS. Four age groups of Sprague-Dawley rats (3, 6, 17, and 52 weeks) were exposed to 300-nm UVR at either 5 or 8 kJ/m 2 , delivered during 15 minutes. The interval between irRadiation and Cataract assessment was 1 or 8 weeks. Moreover, two groups of 6-week-old male and female rats were exposed to 5 kJ/m 2 UVR, with Cataract assessment after 1 week. The severity of Cataract was quantified by measurement of forward light-scattering in isolated lenses. RESULTS. The youngest age group showed development of anterior subcapsular, equatorial, and nuclear Cataract, whereas the three older groups exhibited the first two types. The two younger age groups had significantly more Cataract than the other groups. The degree of Cataract increased from 1 to 8 weeks after irRadiation. There was no difference in Cataract severity between sexes. CONCLUSIONS. Young rats are more sensitive to UVR than old rats. Nuclear UVR Cataract develops in young rats but not in adult rats. With the chosen waveband and dose, the time for maximum Cataract development to occur is longer than 1 week. There is no difference in UVR sensitivity between the sexes.

Susumu Ishida - One of the best experts on this subject based on the ideXlab platform.

  • the clinical features of Radiation Cataract in patients with ocular adnexal mucosa associated lymphoid tissue lymphoma
    Radiation Oncology, 2018
    Co-Authors: Kanae Fukutsu, Satoru Kase, Kan Ishijima, Rumiko Kinoshita, Susumu Ishida
    Abstract:

    To examine the clinical features of Radiation Cataract in patients with ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma. Twenty-one patients with 26 eyes diagnosed with ocular adnexal MALT lymphoma (26 eyes), who were treated in Hokkaido University Hospital, were retrospectively reviewed based on medical records. Out of the 21 patients, 16 patients (21 eyes) received Radiation therapy (RT) with a total dose of 30 Gy. All cases eventually achieved complete remission. Eight of these patients (11 eyes: 52.3%) required Cataract surgery after RT. The mean age at surgery was 56.8 (40–70) years. The mean latency between RT and the indication for surgery was 43.3 months. The percentage of females was significantly higher in patients who required surgery (P < 0.01), compared with those without surgery. The eyes of patients who received bolus technique on Radiation treatment developed Cataract more frequently (P < 0.05). In contrast, none of the patients without RT required Cataract surgery. Patients with ocular adnexal MALT lymphoma who underwent surgery for Radiation Cataract were seen more often in relatively young, female patients, and surgery was required about 3 years after RT. A long-term observation may be needed for patients after RT for a tumor. A female sex and the bolus technique may be risk factors for Radiation Cataract.

E Vano - One of the best experts on this subject based on the ideXlab platform.

  • Radiation and Cataract
    Radiation Protection Dosimetry, 2011
    Co-Authors: Madan M Rehani, E Vano, Olivera Cirajbjelac, Norman J Kleiman
    Abstract:

    When this paper was about to go to press, the International Commission on Radiological Protection released a statement recommending a change in the threshold dose for the eye lens and dose limits for eye for occupationally exposed persons. It is clear that the earlier published threshold for Radiation Cataract is no longer valid. Epidemiological studies among Chernobyl clean-up workers, A bomb survivors, astronauts, residents of contaminated buildings, radiological technicians and recent surveys of staff in interventional rooms indicate that there is an increased incidence of lens opacities at doses below 1 Gy. Nevertheless, eye lens dosimetry is at a primitive stage and needs to be developed further. Despite uncertainties concerning dose threshold and dosimetry, it is possible to significantly reduce the risk of Radiation Cataract through the use of appropriate eye protection. By increasing awareness among those at risk and better adoption and increased usage of protective measures, Radiation Cataract can become preventable despite lowering of dose limits.

  • Radiation Cataract risk in interventional cardiology personnel
    Radiation Research, 2010
    Co-Authors: E Vano, Norman J Kleiman, Ariel Duran, Madan M Rehani, Dario Echeverri, Mariana Cabrera
    Abstract:

    Abstract The lens of the eye is one of the most radiosensitive tissues in the body, and exposure of the lens to ionizing Radiation can cause Cataract. Cumulative X-ray doses to the lenses of interventional cardiologists and associated staff can be high. The International Commission on Radiological Protection recently noted considerable uncertainty concerning Radiation risk to the lens. This study evaluated risk of Radiation Cataract after occupational exposure in interventional cardiology personnel. Comprehensive dilated slit-lamp examinations were performed in interventional cardiologists, associated workers and controls. Radiation exposures were estimated using experimental data from catheterization laboratories and answers to detailed questionnaires. A total of 116 exposed and 93 similarly aged nonexposed individuals were examined. The relative risk of posterior subcapsular opacities in interventional cardiologists compared to unexposed controls was 3.2 (38% compared to 12%; P < 0.005). A total of 21% ...

  • occupational Radiation protection in interventional radiology a joint guideline of the cardiovascular and interventional radiology society of europe and the society of interventional radiology
    CardioVascular and Interventional Radiology, 2010
    Co-Authors: Donald L. Miller, Renato Padovani, E Vano, Gabriel Bartal, Stephen Balter, Robert G Dixon, Beth A Schueler, John F Cardella, Thierry De Baere
    Abstract:

    Fluoroscopically guided interventional procedures are performed in large numbers in Europe and in the United States. The number of procedures performed annually throughout the world has increased over the past 20 years [1]. The benefits of interventional radiology to patients are both extensive and beyond dispute, but many of these procedures also have the potential to produce patient Radiation doses high enough to cause Radiation effects and occupational doses to interventional radiologists high enough to cause concern [1–4]. A joint SIR–CIRSE guideline on patient Radiation management has addressed patient issues [3]. This guideline is intended to serve as a companion to that document and provides guidance to help minimize occupational Radiation dose. The Radiation dose received by interventional radiologists can vary by more than an order of magnitude for the same type of procedure and for similar patient dose [4]. Recently, there has been particular concern regarding occupational dose to the lens of the eye in interventional radiologists [2]. New data from exposed human populations suggest that lens opacities (Cataracts) occur at doses far lower than those previously believed to cause Cataracts [5, 6]. Statistical analysis of the available data suggests absence of a threshold dose, although if one does exist, it is possible that it is less than 0.1 Gy [7, 8]. Additionally, it appears that the latency period for Radiation Cataract formation is inversely related to the Radiation dose [5]. Occupational Radiation protection is a necessity whenever Radiation is used in the practice of medicine. It is especially important for image-guided medical procedures [4, 9]. These procedures may involve high Radiation dose rates in the interventional laboratory [10, 11]. Occupational Radiation protection is necessary, not only during fluoroscopically guided procedures but also during CT-guided procedures, including CT fluoroscopy. CT fluoroscopy is not really fluoroscopy at all. It differs from conventional fluoroscopy in both equipment and technique. The Radiation protection concerns for CT fluoroscopy differ somewhat, particularly in terms of avoiding an excessive Radiation dose to the interventional radiologist’s hands [12, 13]. Occupational Radiation protection requires both the appropriate education and training for the interventional radiologist and the availability of appropriate protection tools and equipment. Occupational Radiation protection measures must also comply with local and national regulations, and should also consider the ergonomic detriment caused by personal protective devices [14–16]. Occupational Radiation protection measures are necessary for all individuals who work in the interventional fluoroscopy suite. This includes not only technologists and nurses, who spend a substantial amount of time in a Radiation environment, but also individuals such as anesthesiologists who may be in a Radiation environment only occasionally. All of these individuals may be considered Radiation workers, depending on their level of exposure and on national regulations. All workers require appropriate monitoring, as well as protection tools and equipment. They must also receive education and training appropriate to their jobs [14]. The level of training should be based on the level of risk. This guideline is intended to offer a basic review of the medical physics relevant to occupational Radiation safety and to provide advice and guidance to interventional radiologists who perform procedures with the guidance of ionizing Radiation and their staff. In this document, the emphasis is Radiation protection during fluoroscopically guided procedures.

Kanae Fukutsu - One of the best experts on this subject based on the ideXlab platform.

  • the clinical features of Radiation Cataract in patients with ocular adnexal mucosa associated lymphoid tissue lymphoma
    Radiation Oncology, 2018
    Co-Authors: Kanae Fukutsu, Satoru Kase, Kan Ishijima, Rumiko Kinoshita, Susumu Ishida
    Abstract:

    To examine the clinical features of Radiation Cataract in patients with ocular adnexal mucosa-associated lymphoid tissue (MALT) lymphoma. Twenty-one patients with 26 eyes diagnosed with ocular adnexal MALT lymphoma (26 eyes), who were treated in Hokkaido University Hospital, were retrospectively reviewed based on medical records. Out of the 21 patients, 16 patients (21 eyes) received Radiation therapy (RT) with a total dose of 30 Gy. All cases eventually achieved complete remission. Eight of these patients (11 eyes: 52.3%) required Cataract surgery after RT. The mean age at surgery was 56.8 (40–70) years. The mean latency between RT and the indication for surgery was 43.3 months. The percentage of females was significantly higher in patients who required surgery (P < 0.01), compared with those without surgery. The eyes of patients who received bolus technique on Radiation treatment developed Cataract more frequently (P < 0.05). In contrast, none of the patients without RT required Cataract surgery. Patients with ocular adnexal MALT lymphoma who underwent surgery for Radiation Cataract were seen more often in relatively young, female patients, and surgery was required about 3 years after RT. A long-term observation may be needed for patients after RT for a tumor. A female sex and the bolus technique may be risk factors for Radiation Cataract.