Contact Lens Capsule

A method for removing hydrogen peroxide from soft contact lenses which have been sterilized with hydrogen peroxide is disclosed in U.S. pat. application Ser. No. 454,141, the disclosure of which is incorporated herein, as an alternative to the method of sterilizing these lenses by boiling in an aqueous solution. This method comprises immersing the soft contact lenses in an aqueous system containing a decomposition catalyst which acts on the hydrogen peroxide to convert it to water and free oxygen.

In the above procedure an amount of 3% by weight of hydrogen peroxide containing sufficient sodium chloride to yield a 0.85% saline solution is introduced into a container comprising a cup, a contact lens basket, and a desired decomposition catalyst. The lenses are then allowed to remain in contact with the hydrogen peroxide solution for approximately 6 hours. After this time, the lenses are effectively sterilized and the concentration of hydrogen peroxide is reduced to about 20 PPM. To avoid possible discomfort, a single rinse in isotonic saline may subsequently be affected to reduce the hydrogen peroxide concentration to less than 10 PPM, an amount which can be readily tolerated in the eye.

In the present invention, a sterilizing capsule having the characteristics to be herein described is highly effective in carrying out soft contact lens sterilizing procedures using a hydrogen peroxide decomposition catalyst system.

Accordingly one object of the present invention is to provide an improved capsule for use in a hydrogen peroxide sterilizing procedure for affecting the sterilization of soft contact lenses.

Another object of the present invention is to provide an improved sterilizing capsule which is sealed to contain the sterilizing solution but which allows the oxygen produced during the hydrogen peroxide decomposition reaction to escape.

The exact manner in which these and other objectives of this invention are achieved will become apparent when references made to the following detailed description of the preferred embodiments of the invention and to the accompanying drawings in which like reference numerals indicate corresponding parts throughout the several views of the drawings.

In the drawings:

FIG. 1 is a side elevational view of the assembled capsule;

FIG. 2 is a vertical cross sectional view of the upper cap of the capsule;

FIG. 3 is a view of the base of the upper cap;

FIG. 4 is a plan view of the lower cap of the capsule;

FIG. 5 is an exploded perspective view of the capsule according to the present invention;

FIG. 6 is a vertical cross sectional view of a modified form of the upper cap;

FIG. 7 is a view of the base of the cap of FIG. 6;

FIG. 8 is a vertical cross sectional view of another modified form of the upper cap;

FIG. 9 is a vertical cross sectional fragmentary view of the upper cap of FIG. 10 taken along line 9--9;

FIG. 10 is a plan view of the upper surface of a cap having a modified central post structure.

Referring to the drawings and specifically to FIG. 1, the sterilizing capsule of my invention consists of a hollow cylindrical body 50 having male screw threads 51 on each end thereof which carry a bottom cap 40 and an upper cap 20. The female screw threads 45 of the bottom cap capable of engaging the threads at one end of the body with the connection being sealed by a gasket 41 located at the base of cap 40. This construction produces a water proof seal when the bottom cap is tightened against the piece of body 50. The bottom cap also carries a vertical disposed axial post 42 on which is mounted a convoluted catalytic reactor 43 which is held to this central post by friction. The preferred catalytic material is a surface layer of platinum black which has been deposited on a molded substrate of the desired shape. The substrate is molded in the form of a split ring provided with inner gripping means 44 which grip the central post for a friction fit.

In order to support the contact lenses during sterilization, a lens basket 11 is attached by means of a support post 12 to the inner surface of the upper cap by any conventional method such as the use of adhesives, friction or snap fittings, or alternatively, the support posts may be molded as part of the upper cap.

The upper cap 20 comprises as shown in FIGS. 1 and 2 an outer circumferential collar 13 and spaced inwardly thereof, a central post 21 extending upwardly along the central axis of the cap and terminating in a flat top surface 22. The collar may be shaped to form raised portions along a common diameter of a cap defining wings 23 to aid in gripping the cap when attaching and detaching it from the body 50. The female screw threads 28 of the cap are adapted to engage the corresponding male threads on the body 50 and thereby allow the two units to be connected. The upper cap is also provided with a gasket 29 which produces a water proof seal when the cap is firmly attached to the body.

An axial core opening extends from the inner base of the cap into an axial core cavity 25 extending upward into the post a distance short of the flat top. This cavity connects with radial openings 26 which extend through the central post to the apex of a truncated conical annular groove 27 extending circumferentially about the post. A flexible seal 24 in the form of an elastic O-ring fits into this groove and the pressure asserted by the flexible seal against the annular groove affords a liquid proof seal which prevents any liquid contained in the body of the assembled capsule from escaping.

A core opening restriction means is located at the core opening in the base of the cap, and may comprise a disc 31 provided with perforations 32, a baffle means having channels as shown in FIGS. 7 and 10, or a venturi constriction as shown in FIG. 8.

In use the soft contact lenses are placed within the basket and the upper cap carrying the basket is firmly attached to the open cylindrical body. Hydrogen peroxide sterilizing solution is then poured into the open end of the capsule until the lenses and basket are immersed. The capsule is then sealed by attaching the lower cap carrying the catalyst. The capsule is then allowed to remain inverted to allow the hydrogen peroxide to act without being in contact with the catalytic reactor. After the desired period of sterilization is completed, the capsule is inverted so that it now rests upon the base of the lower cap and the hydrogen peroxide is in contact with the catalytic reactor. During sterilization, the O-ring seal will prevent the solution from leaking out of the capsule. At the end of the sterilization, when the capsule is reversed, the hydrogen peroxide solution comes in contact with the catalyst which acts to decompose the hydrogen peroxide to form water and oxygen. As the pressure of the oxygen formed within the capsule increases, the seal formed by the O-ring acts as a pressure release valve and the oxygen is thus allowed to escape.

A modified form of cap 60 as shown in FIG. 6 comprises a cylindrical collar 13 having an inner annular flange 65 through which a separate detachable inner post 66 is passed. This post is cylindrical in shape and has a core opening, a core cavity, radial openings, female threads, and a gasket as previously described. The detachable post is of a diameter sufficient to fit within the central opening of the collar's annular flange; the post itself has a radially extending circumferential flange 64 having a diameter to cooperatively fit into the cavity defined by the female threads of the collar and to abut the annular flange. The core opening within the post carries a cylindrical solid baffle 62 having a spacing tab 63 which effectively limits the baffle at a sufficient distance below the radial openings to form the core cavity. The longitudinal surface of the baffle is grooved to form a series of annular channels 71 communicating with the core opening and the core cavity. A tab 61 extends from the baffle in opposite direction to the space tab and carries a basket support structure. The unit is assembled by inserting the detachable post into the central opening of the annular flange until the circumferential flange abuts the annular flange of the collar assembly. The gasket is then positioned about the lower perimeter of the post flange thus assuring a water proof seal when the cap is firmly attached to the body.

FIG. 8 shows another modified cap 80 having a detachable central post 85. The collar 81 in this modification is elongated to extend a greater distance than the post when the cap is assembled and thus the collar's upper surface forms a surface upon which the unit rests when inverted and the lenses are being sterilized. The inner surface of the collar includes an inwardly extending stop means 82 located at the base of the female screw threads 83 and capable of abutting the flange 84 extending outwardly from the central post and spaced along the length of the post, thereby limiting the post within the collar when the cap is assembled. The core opening 86 of the central post is a venturi-like constriction, generally a truncated conical bore, which terminates at the core cavity.

The modified central post in FIG. 9 does not contain radial openings through the post, but terminates in a top surface 99 which tapers centrally from the perimeter of the post to the core cavity. Spacing means 94 located either on the upper surface of the post as shown, or on the lower surface of the flat discoidal cover 91, space the cover at a distance from the upper surface of the post when the cap is assembled. The cover has an axial downward extending post 92 of an outer diameter less than the diameter of the core cavity and carries guiding and spacing ribs 95, which cooperate with the surface of the cavity to position the post within the cavity and also to form longitudinal channels 96 which connect with the core opening and the space between the cover and post surfaces. The outer perimeter 97 of the cover is beveled centrally and downwardly and cooperates with the downwardly and outwardly beveled perimeter 98 of the upper post surface to form a truncated conical annular groove in which the O-ring seal is held.

Having described my invention, and the manner and process of making and using it in such full, clear, concise and exact terms as to enable any person skilled in the art to which it pertains to make and use the same,