The invention is intended for the ophthalmology sector of the market, within the area of optical applications of a therapeutic and preventive nature.
The invention generally provides a transparent filtering optic medium, or yellow pigment, applied to the transparent or translucent vertical surfaces of buildings to protect healthy eyes and/or pseudophakic eyes (eyes that have undergone cataract surgery) and/or eyes with retinal degeneration from the short wavelengths of the visible spectrum from 500 to 380 nm that cause retinal degeneration. As an example, this filtering component is indicated for use in windows for houses, offices, and shops.
Visual perception is the result of the response to visible radiation in the wavelength range 380-760 nm. In the environment, solar radiation is the main risk factor for vision. The sun emits UV rays and IR radiation, which are mainly absorbed by the atmosphere. When the solar radiation transmitted through the atmosphere reaches the Earth's surface it consists of UV-B rays (230-300 nm), UV or UV-A rays (300-380 nm), visible light rays (380-760 nm) and IR rays (760-1400 nm). Healthy human eyes freely transmit IR rays and those of most of the visible spectrum to the retina, but the cornea and crystalline lens prevent the most reactive wavelengths of the visible spectrum (UV-B rays and the blue portion of the spectrum) from reaching the retina.
The human crystalline lens changes its transmission properties as it ages by intensifying its yellowish colour thus increasing its capacity to filter out UV and blue light rays. Hence, in persons older than 65 years, violet light (<400 nm) is not transmitted and the transmission of blue light (400-500 nm) is markedly reduced.
The retina is capable of protecting itself from short wavelengths of light in two ways: through its uneven distribution of photoreceptors, such that there are no photoreceptors sensitive to blue light in the macular depression; and through the actions of yellow pigments in this zone, which also exert a protective effect.
These natural protection systems the human eye has against the shorter wavelengths of light—the crystalline lens and structures of the retina—can be seriously affected by certain diseases and/or surgical procedures:
We should also consider that both cataracts and AMD can coexist in persons older than 65 years. In this population of elderly subjects, cataract is the main cause of vision loss and AMD is the main cause of blindness. In addition we should expect an increase in both these diseases due, among other factors, to our increased life expectancy. This translates into a great interest in these diseases and their treatment options in the research field and optics industry.
Several epidemiological studies have evaluated the relationship between cataract surgery and AMD. Thus, Klein (Klein R, Klein B E, Wong T Y, Tomany S C, Cruickshanks K J. The association of cataract and cataract surgery with the long-term incidence of age-related maculopathy. Arch Ophthalmol 120:1551-1558.2002) and Freeman (Freeman E, Muñoz B, West S K, Tielsch J M, Schein O D. Is there an association between cataract surgery and age-related macular degeneration? Am J Ophthalmolm 135(6): 849-856.2003) claim there is a higher risk of developing symptoms of AMD in persons who have undergone cataract surgery. However, in earlier investigations by Wang (Wang J J, Mitchell P, Cumming R G, Lim R. Cataract and age-related maculopathy: the Blue Mountains Eye Study. Ophthalmic Epidemiol 6: 317-326.1999) and McCarty (McCarty C A, Mukesh B N, Fu C L, Mitchell P, Wang J J, Taylor H R. Risks factors for age-related maculopathy: the Visual Impairment Project. Arch Ophthalmol 119:1455-1462.2001) this hypothesis was rejected, possibly because of the less developed technology used for their diagnostic measurements. Techniques such as optical coherence tomography that allow the accurate, rapid and non-invasive follow up of retinal neurodegeneration processes have only recently been introduced. These techniques are essential for establishing the determining effect of the natural pigments that absorb harmful radiations.
Several techniques have also been developed to protect eyes subjected to cataract surgery from short wavelengths of light:
Several patents related to the state of this technique have been developed (for healthy, pseudoaphakic eyes and/or eyes undergoing neurodegeneration) although they differ considerably from the object of the present invention:
These devices differ from the present invention mainly in their purpose and utility since none has been designed to protect eyes from short wavelengths of the visible spectrum to prevent and reduce neurodegenerative retinal processes.
The aim of the invention is generally to protect and prevent eyes from absorbing blue and violet light by means of a filter applied to the transparent or translucent surfaces of a building. As mentioned above, it is particularly useful in the case of pseudophakic persons, to functionally compensate for their lack of protective pigments (removed during surgery), and as prophylaxis for subjects suffering neurodegeneration. Both these conditions are common among elderly persons but the invention is equally important for protecting healthy eyes in any subject.
The invention is prepared by applying to the transparent or translucent surfaces of a building, in which the subject may be found, a yellow filter that absorbs short wavelengths from 500 to 380 nm. As an example, this filter could be applied to the windows of houses, offices or shops.
The invention thus combines three components:
There are several ways of manufacturing the invention depending on the material of the surface to which the filter will be applied. The instructions below are provided as an example for use in the glass of a house window, but are in no way restrictive.
The following layers of glass can be used to manufacture the window: transparent monolithic glass of 90% Tvis (visible light transmittance); yellow-tinted monolithic glass of 62% Tvis, laminated monolithic glass of 88% Tvis, transparent satin glass of 82% Tvis, yellow-tinted satin glass of 56% Tvis, laminated satin glass of 80% Tvis.
Thus, by combining several transparent or translucent surfaces of a building in which a subject may be found with a yellow filter, any individual can protect his/her healthy eyes from short wavelengths of light and patients who have undergone cataract extraction and the implant of a transparent intraocular lens can correct their lack of natural protection. Moreover, eyes with neurodegeneration can improve since the invention enhances their natural protection. In this way, the problems related to the technical options available on the market can be avoided (filters with no application system and intraocular lenses).
Number | Date | Country | Kind |
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200701515 | Jun 2007 | ES | national |
This application is related to and claims the benefit of: U.S. Provisional Patent Application Ser. No. 60/950,441 filed on 17 Jul. 2007; and Spanish Patent Application Ser. No. 200701515 filed on 01 Jun. 2007. Both of said applications are herein incorporated by reference in their entirety.
Number | Date | Country | |
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60950441 | Jul 2007 | US |