The Spectra, Classification, and Rationale of Ultraviolet-Protective Intraocular Lenses
I measured the spectral transmittance of 16 implantable intraocular lenses from 12 manufacturers and examined the rationale for using ultraviolet-absorptive intraocular lenses to protect pseudophakic individuals from photic retinopathy. Each ultraviolet-protective lens was classified by the wavelength at which its spectral transmittance fell to 10% in the blue or ultraviolet region of the spectrum. Current ultraviolet-protective intraocular lenses differ in the effectiveness of their protection against photic retinopathy, and product descriptions may be misleading.
Available from: Ian Wong
- "A theoretical link has been proposed between phototoxicity and cataract extraction . Most modern-day IOLs mimic the crystalline lens in filtering the harmful UV spectrum of 300–400 nm [78, 81]. The human crystalline lens turns yellow with age, thereby blocking blue light (400–500 nm), while IOLs tend to be transparent . "
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ABSTRACT: Age-related macular degeneration (AMD) is one of the leading causes of blindness in the developed world. Although effective treatment modalities such as anti-VEGF treatment have been developed for neovascular AMD, there is still no effective treatment for geographical atrophy, and therefore the most cost-effective management of AMD is to start with prevention. This review looks at current evidence on preventive measures targeted at AMD. Modalities reviewed include (1) nutritional supplements such as the Age-Related Eye Disease Study (AREDS) formula, lutein and zeaxanthin, omega-3 fatty acid, and berry extracts, (2) lifestyle modifications, including smoking and body-mass-index, and (3) filtering sunlight, i.e. sunglasses and blue-blocking intraocular lenses. In summary, the only proven effective preventive measures are stopping smoking and the AREDS formula.
International Ophthalmology 02/2011; 31(1):73-82. DOI:10.1007/s10792-010-9397-5 · 0.55 Impact Factor
Available from: Lyndon W Jones
- "Also, class I UV-absorbing silicone hydrogel polymers have been introduced most recently, and, to date, little has been published on the UV-attenuating properties of silicone hydrogel contact lenses [10,11]. Most intraocular lenses incorporate UV blocking chromophores, but several intraocular lenses currently in use exhibit inadequate light-absorbing properties [12,13]. Thus, there is a need to evaluate and compare the performance of these UV-absorbing ophthalmic biomaterials. "
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ABSTRACT: The purpose was to develop suitable in vitro methods to detect ocular epithelial cell damage when exposed to UV radiation, in an effort to evaluate UV-absorbing ophthalmic biomaterials.
Human corneal epithelial cells (HCEC), lens epithelial cells (HLEC), and retinal pigment epithelial cells (ARPE-19) were cultured and Ultraviolet A/Ultraviolet B (UVA/UVB) blocking filters and UVB-only blocking filters were placed between the cells and a UV light source. Cells were irradiated with UV radiations at various energy levels with and without filter protections. Cell viability after exposure was determined using the metabolic dye alamarBlue and by evaluating for changes in the nuclei, mitochondria, membrane permeability, and cell membranes of the cells using the fluorescent dyes Hoechst 33342, rhodamine 123, calcein AM, ethidium homodimer-1, and annexin V. High-resolution images of the cells were taken with a Zeiss 510 confocal laser scanning microscope.
The alamarBlue assay results of UV-exposed cells without filters showed energy level-dependent decreases in cellular viability. However, UV treated cells with 400 nm LP filter protection showed the equivalent viability to untreated control cells at all energy levels. Also, UV irradiated cells with 320 nm LP filter showed lower cell viability than the unexposed control cells, yet higher viability than UV-exposed cells without filters in an energy level-dependent manner. The confocal microscopy results also showed that UV radiation can cause significant dose-dependent degradations of nuclei and mitochondria in ocular cells. The annexin V staining also showed an increased number of apoptotic cells after UV irradiation.
The findings suggest that UV-induced HCEC, HLEC, and ARPE-19 cell damage can be evaluated by bioassays that measure changes in the cell nuclei, mitochondria, cell membranes, and cell metabolism, and these assay methods provide a valuable in vitro model for evaluating the effectiveness of UV-absorbing ophthalmic biomaterials, including contact lenses and intraocular lenses.
Molecular vision 01/2011; 17:237-46. · 1.99 Impact Factor
Available from: Bernt Ralph Chou
- "32233); Fax: 1-519-725-0784; E-mail: firstname.lastname@example.org damage DNA, leading to DNA fragmentation   , and decrease mitochondrial function   . "
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ABSTRACT: This work involves the evaluation of UV blocking efficiency of commercially available intraocular lens (IOL) materials using a retinal cell culture and a biological in vitro model that was developed in a previous study, as an effort to examine the sensitivity of this in vitro approach for evaluating toxicity of UV radiation on the retinal pigment epithelial cells. The human retinal pigment epithelial (RPE) cell line, ARPE-19, was cultured, and cells were irradiated with broadband UVB radiations at energy levels of 0.2 and 0.4 J/cm. Some treated cells were not shielded from the radiation while others were shielded using two thicknesses (0.9 and 1.5 mm) of IOL material. After irradiation, cellular viability, mitochondrial distribution, nuclei morphology, and phagocytotic activity were analyzed using the Alamar blue assay, Rhodamine 123 staining, the Hoechst assay, and a phagocytotic activity assay. The results demonstrate that UVB radiation can cause significant decreases in RPE cell viability as well as in phagocytotic activity. Also, the results show that UVB radiation can induce the degradation of DNA and mitochondria in cultured RPE cells. However, the two different thickness IOL material sheets (0.9 and 1.5 mm) showed very effective UV blocking ability, allowing no cellular damage at all. Thus, the finding suggest that these four assays together can be used as a sensitive, and meaningful in vitro biomarker method for evaluating toxicity of UV radiation on RPE cells, and also for examining IOL effectiveness.
The Open Toxicology Journal 04/2010; 4(1). DOI:10.2174/1874340401004010013
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