Special receptacle or package – For eyeglass or spectacle – Contact lens
Reexamination Certificate
2000-08-09
2002-05-07
Fidei, David T. (Department: 3728)
Special receptacle or package
For eyeglass or spectacle
Contact lens
C134S901000, C422S301000
Reexamination Certificate
active
06382408
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the art of for cleaning contact lenses and in a specific embodiment to apparatus for performing a multi-step cleansing of contact lenses where, during a first step, cleansing is performed using a high and substantially constant concentration of the cleansing agent or agents in the cleansing fluid and where, during a second, subsequent step, the cleansing agent or agents are neutralized and/or the cleansing fluid is altered in order to make the cleansed contact lenses more suitable for insertion onto a users eyes.
2. Description of the Related Art
A high concentration of the cleaning substance in the cleaning fluid is required, because some of the impurities usually deposited on the lenses require a long exposure time to a disinfection fluid, e.g. hydrogen peroxide with a concentration of 3-4 vol. %, in order to be removed. Examples of such impurities are acanthameoba, candida albicans, yeast cells, different vira and different bacteria spores. These impurities are known to be very resistant to commonly used disinfection fluids, so in order to remove such impurities, a long exposure time is required with a high concentration of the active substance in the disinfection or cleansing fluid.
Furthermore, e.g. bacteria can excrete chemical/biological substances which can encapsulate the bacteria, i.e. form a film of chemical/biological substances which adhere to the surface of a contact lens. Thus, a long exposure time is also required in order for the disinfection or cleansing fluid to penetrate and thereby remove the bacteria and bacteria spores and the film of chemical/biological substances.
In fact, most of the presently known apparatus and methods may be denoted as bacteriostatic in that the interaction with the cleansing fluid is only sufficient for maintaining a level of bacterial contamination in the container used for holding the contact leans during cleansing.
Known apparatus for cleansing contact lenses are typically ones in which the contact lens and the cleansing fluid are introduced into a container. However, in order to avoid requiring that the user himself has to introduce an agent for neutralizing the cleansing fluid (in order to render the contact lens suitable for introduction onto the users eye), this neutralizing agent is introduced from the beginning of the process. Consequently, the neutralization of the cleansing fluid takes place during the full process, whereby the concentration of the cleansing agent is only optimum for a short period of time. Naturally, this requires a longer period of time for a suitable cleansing of the contact lens.
Apparatus which attempt to postpone the active neutralization process of the disinfection fluid are known from EP 2 658 422. In this apparatus the neutralizing agent is placed in the container wherein the disinfection process takes place by means of a mechanical device. This mechanical device can be driven by an electric motor or it can be driven manually.
Another apparatus which attempts to postpone the relief of a neutralising agent is known from GB 2 301 1 98 A. In this apparatus the neutralising agent is kept in a cavity defined by a tubular part being open ended in one end only. The cavity is sealed by a lid settled inside the tubular part, which lid swells when in contact with a disinfecting fluid. As the lid is settled inside the tubular part, a cavity, defined by side parts of the tubular part and the lid, is present on top of the lid. Due to the small dimension of the apparatus and the surface tension in the disinfecting fluid, air bubbles will tend deposit in this cavity in use. If an air bubble deposits in the cavity, access to the surface of the lid is hindered and the swelling process will not take place, whereby no access for the cleaning fluid to the neutralising agent is provided and the neutralisation process does not take place. Furthermore, the introduction of the apparatus into a receptacle used for the cleaning process is critical in the sense that no swelling of the lid will occur, if the apparatus “lands” standing on its open end, due to the fact that no fluid or not a sufficient amount of the fluid will be able to get into contact with the lid.
Other manners of delaying the introduction of the neutralizing agent would be using the well known sustained release principle where the agent is formed into a pill or pellet covered by a layer dissolved by the cleansing agent. In this manner, the neutralizing agent is not released until the layer has been dissolved. This method, however, has the disadvantage that the material of the layer and e.g. pill manufacturing helping agents will be released to the cleansing agent, part of which will be introduced onto the eye of the user or will remain in the container means used for the cleansing. These materials are typically of a type that attracts and holds bacteria and, consequently, facilitates bacterial growth in the container means and hence on the contact lenses.
BRIEF SUMMARY OF THE INVENTION
Thus, it is an object of the invention to provide a container means for use in cleansing a contact lens, which firstly is able to reduce or fully obviate the introduction of unsuitable agents (mostly agents irritating to the eye) in the cleansing fluid, and which secondly is adapted to fully delay the neutralization of the cleansing agent until after a desired period of time where the contact lens has been sufficiently cleansed. Both these objects will help to reduce the bacterial growth in the container used for the cleansing and thereby the concentration of bacterial present on the cleansed contact lens. Thus, the present method will facilitate bactericide cleansing—that is, a cleansing actually reducing the number of bacteria in the container and, thus, on the cleansed contact lens.
These objects are obtained by a container means suitable for holding at least one substance for use in a process for cleaning contact lenses using a fluid, the container means comprising:
at least one first and at least one second part assembled/combined to form a sealed cavity for holding the at least one substance,
the second part(s) being formed of a material having a second expansion coefficient when embedded in the fluid and being at least substantially insoluble in the fluid, the second part(s) having outer surface(s) constituting part(s) of an outer surface of the container means,
the first part(s) being formed of a material having a first expansion coefficient when embedded in the fluid and being at least substantially insoluble in the fluid, the first expansion coefficient being smaller than the second expansion coefficient,
wherein
the container means has at least one cross section wherein the first part(s) define(s) an envelope curve and wherein at least one part of the second part(s) extend(s) outside the envelope surface,
and/or
two or more parts of the outer surface of the assembled/combined container means are constituted by surface parts of the second part(s) at at least two different sides thereof.
It should be noted that, in the present context, an expansion coefficient may be negative so that the material, in fact, shrinks when in contact with the fluid.
In the following, the invention will be described where one of the materials expands more than the other. It should be noted that exactly the same effect will be achieved if the other material shrinks correspondingly in relation to the first material.
The material being able to expand should be at least substantially insoluble in the so as to avoid polution of the fluid used in the process for cleaning contact lenses. Polution may e.g. be the case where the material is no longer interconnected so that the material is able to deposit on the lenses. It is preferred that the fraction of the material no longer being interconnected should be less than 5%, preferably less than 4%, such as less than 3%, preferably less than 2%, such as less than 1%, preferably less than 0.5, even less than 0.25% and preferably less than 0.125%, the amount be
Fidei David T.
Synoptik A/S
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