The present invention relates to silicone hydrogel contact lenses and the production thereof. More particularly, the present invention relates to systems and methods for producing silicone hydrogel contact lenses.
Soft contact lenses can be produced in plastic contact lens mold assemblies by polymerizing lens precursor compositions in the contact lens mold assemblies. Existing contact lens mold assemblies comprise a first mold section and a second mold section. Each mold section has a single surface that corresponds to a surface of a soft contact lens having an optically acceptable quality. When mold sections formed from polypropylene or other similar materials are used to form mold assemblies, the assemblies are formed from an interference fit between the first and second mold sections.
A lens precursor composition contained in the mold assembly can be polymerized to form a contact lens located in a lens shaped cavity of the mold assembly. For example, a lens precursor composition can be exposed to ultraviolet light to polymerize the composition. The light delivered to the lens precursor composition is usually not uniformly or constantly applied to the mold assemblies since light-emitting lamps are located on only one side of the mold assemblies. To address this issue, the light emitted from the lamps is delivered at high intensities. However, the light is still not uniform or constant.
After polymerizing the lens precursor composition, the mold sections are separated by breaking the interference fit between the two mold sections. Unreacted monomers and the like can be extracted, and the lens can be packaged. For silicone hydrogel contact lenses, the extraction process often requires the lens to be contacted with an organic solvent. After a period of time, when the solvent has become contaminated with the unreacted monomers, the solvent is discarded.
In addition, since a silicone hydrogel contact lens formed in a polypropylene mold or other mold formed from similar materials has surfaces with insufficient wettability characteristics required for ophthalmic use, the silicone hydrogel contact lens undergoes a surface treatment or surface modification to enhance the wettability of the lens surfaces.
Thus, there remains a need for improved systems and methods for producing silicone hydrogel contact lenses that reduce manufacturing time, manufacturing costs, and/or produce large quantities of silicone hydrogel contact lenses that are ophthalmically acceptable and provide vision enhancement with little or no negative side effects.
The present systems and methods address this need and are used to produce silicone hydrogel contact lenses, such as extended wear contact lenses. The present systems and methods form a plurality of substantially identically structured mold sections that have two optical quality surfaces in a lens forming region of the mold sections. A lens precursor composition is placed on one surface of a mold section. A second mold section is placed over the mold section containing the lens precursor composition to form a lens shaped cavity with the composition located therein. The resulting contact lens mold assembly and the lens precursor composition are exposed to a polymerizing agent, such as ultraviolet light, to form a silicone hydrogel contact lens located in the lens shaped cavity. The mold sections are separated and the lens is removed from one mold section, and is contacted by an extraction medium to remove extractable components from the lens. The lens is then hydrated to form a swelled silicone hydrogel contact lens. Optionally, the swelled lens can be inspected and packaged for distribution.
Each and every feature described herein, and each and every combination of two or more of such features, is included within the scope of the present invention provided that the features included in such a combination are not mutually inconsistent. In addition, any feature or combination of features may be specifically excluded from any embodiment of the present invention.
These and other aspects of the present invention are apparent in the following detailed description and claims, particularly when considered in conjunction with the accompanying drawings in which like parts bear like reference numerals.
Systems and methods for producing silicone hydrogel contact lenses have been invented. As used herein, a silicone hydrogel contact lens is a contact lens that has a high oxygen permeability and an ophthalmically acceptable water content. Silicone hydrogel contact lenses can be understood to be contact lenses that comprise a silicone hydrogel material. For example, silicone hydrogel contact lenses can comprise one or more hydrophilic silicon-containing macromers. Examples of suitable materials used to make silicone hydrogel contact lenses include, without limitation, galifilcon A, senofilcon A, lotrifilcon A, lotrifilcon B, or balifilcon A. Additional examples of materials used to make the present silicone hydrogel contact lenses include those materials disclosed in U.S. Pat. No. 6,867,245.
The lenses produced using the present systems and methods can be understood to be extended wear contact lenses. For example, the lenses can be worn by a person continuously for more than one day (e.g., 24 hours) without undue discomfort or damage to the eye. Certain lenses can be worn for at least five days, for example for about one or two weeks, or for about thirty days or more.
The present systems and methods are preferably automated and are configured to produce large amounts of contact lenses in reasonably acceptable amounts of time.
As shown in
One of the present methods comprises a step 110 of forming a plurality of contact lens mold sections. Each mold section is substantially identical to the other mold section for a given lot of mold sections. Thus, a batch of mold sections can be produced that are all substantially identical in structure. Each mold section comprises a lens forming region. The lens forming region comprises a concave surface which is a negative of an optical quality anterior surface of a contact lens, and a convex surface which is a negative of an optical quality posterior surface of a contact lens.
An example of a mold section produced using the present methods and systems is illustrated in
In certain embodiments, eight mold sections can be produced at a time or in a single step. The eight mold sections can then be transferred to a tray which can hold a total of five hundred twelve substantially identical mold sections.
In the illustrated embodiment, which is provided by way of example and not by way of limitation, the method may comprise an optional step of forming an elongate member 1012 on the mold sections 1010, as shown in
The lens forming region 1014 of the mold section 1010 can be formed using two optical inserts, each insert having a smooth surface sufficient for forming an optical quality surface of the mold section, as discussed herein. Each insert can be provided in a plate used to form the mold cavity. The shape of the smooth surface of the optical inserts imparts certain design features to the present contact lenses, such as optical power, and the like. Thus, different batches of mold sections can be produced by replacing the optical inserts in the plates with different optical inserts. One advantage of producing substantially identically structured mold sections, such as mold sections having two optical quality surfaces, is that the systems comprise a reduced number of components or parts, a reduced number of molding machines, and/or enhancements in inventory management relative to existing systems which form mold sections that have only one optical quality surface.
As shown in
The lens precursor composition comprises a plurality of monomers which can be polymerized upon exposure to a polymerization source, such as light, heat, and the like. Light sensitive compositions are preferably stored in devices that block or filter ambient polymerizing light to prevent premature polymerization of the composition. The present compositions can also be stored at a controlled temperature, for example about room temperature (e.g., 20-25° C.) using a temperature controller. For example, the body 1114 can be formed of a UV resistant material to prevent or reduce the amount of UV light exposed to the lens precursor composition 1118.
After placing the lens precursor composition 1118 on the concave surface 1016 of the mold section 1010, the method can comprise a step 114 of placing a second mold section on the first mold section so that the convex surface of the second mold section and the concave surface of the first mold section form a contact lens shaped cavity. The combination of the first mold section and the second mold section located thereon is referred to as a contact lens mold assembly. A contact lens mold assembly 1020 is illustrated in
The first and second mold sections 1010 of the mold assembly 1020 can be held together using a variety of techniques. For example, the mold sections can be held together by pressure applied to opposing plates contacting opposite sides of the mold assembly. Or, the mold sections can be held together by an interference fit between the first mold section and the second mold section. Or, the mold sections can be welded together. Welding appears to provide benefits when the mold sections are formed from EVOH and similar materials. In the illustrated embodiment, the welding of the first mold section and the second mold section to each other can comprise forming a discontinuous ring around the lens forming region of the mold assembly 1020 using an ultrasonic delivery device 1210, as shown in
The lens precursor composition can then be polymerized as shown at step 116 in
After the lens precursor composition is polymerized, the method may comprise a step 216 of separating the second mold section and the first mold section. In certain embodiments, the separating comprises placing a wedge or other separation device 1510, as shown in
As shown in
As shown in the side view of
To separate the mold sections of the mold assembly 1020, the mold assembly 1020 contacts the wedges 1516a and 1516b between the two mold sections of the mold assembly. The mold assembly 1020 moves relative to the wedges 1516a and 1516b until the second mold section is separated from the first mold section due to the stress caused by the progressively increasing thickness of the wedges. Alternatively, the separators could be moved relative to the mold assembly if desired.
In certain embodiments, the present methods may comprise a step of contacting the silicone hydrogel contact lens with a liquid to detach the lens from a surface of the separated mold section. For example, a contacting step may comprise placing the mold section containing the polymerized contact lens in a volume of water. The water, or other suitable liquid, causes the lens to swell or expand and become detached from the surface of the mold section. Although the swelled lens is detached from the surface, it is still retained in the lens shaped region of the mold section due to the concave shape of the lens region of the mold section.
After the mold sections are separated, the method comprises a step 120 of removing the silicone hydrogel contact lens from the mold section, as shown in
The removing 120 of the present methods may comprise a step of applying negative pressure to a surface of the contact lens using a vacuum apparatus to separate the contact lens from the mold section. More specifically, and as shown in
As shown in
As shown in
As shown schematically, extraction media from any of the extraction stations 1714 can be directed through a conduit 1724 for recycling. The media may be passed through one or more filtration devices and/or other processing devices 1722 before being added back into any one of the extraction stations 1714 for further use. Thus, the present extraction system can provide substantial reduction in expenses compared to other systems which discard the extraction media.
After the extraction step or steps, the method may comprise a step 124 of placing the silicone hydrogel contact lens in an aqueous medium to hydrate the lens. For example, the contact lens or lenses may be placed in deionized water and the like to saturate the lens or swell the lens. As discussed above, this can occur in the housing 1712 or separately.
Optionally, the present methods may comprise inspecting the contact lens for defects, such as tears, surface irregularities, chips, and the like. The inspection can be performed manually using a magnifying instrument, or can be automated using a computer, digital camera, and software to detect lens defects. The lenses can be inspected either in a volume of liquid, or on a planar surface without a body of liquid.
After the optional step of inspection, the present lenses can be placed into a sealable package, such as the package 1410 shown in
Advantageously, the present silicone hydrogel contact lenses 1413 can be placed in a hydrophobic package and not adhere to a surface of the package without requiring the presence of a surfactant or surface modification of the package. In addition, the present lenses do not require a surface modification or surface treatment to make the contact lens surfaces wettable.
As shown in
As shown schematically in
Some aspects of other systems and methods of producing contact lenses are disclosed in the following U.S. Patents and Patent Publications: U.S. Pat. Nos. 6,592,356; 5,540,410; 5,759,318; 5,593,620; 5,597,519; 6,359,024; 2003/0090014; U.S. Pat. Nos. 5,850,107; 5,820,895; 5,935,492; 5,836,323; 6,288,852; 6,531,432; and 2005/0171232.
Certain aspects and advantages of the present invention may be more clearly understood and/or appreciated with reference to the following commonly owned United States Patent Applications, filed on even date herewith, the disclosure of each of which is being incorporated herein in its entirety by this specific reference: U.S. patent application Ser. No. 11/200,848, entitled “Contact Lens Molds and Systems and Methods for Producing Same”; U.S. patent application Ser. No. 11/200,648, entitled “Contact Lens Mold Assemblies and Systems and Methods of Producing Same”; U.S. patent application Ser. No. 11/200,644, entitled “Systems and Methods for Producing Contact Lenses from a Polymerizable Composition”; U.S. patent application Ser. No. 11/201,410, entitled “Systems and Methods for Removing Lenses from Lens Molds”; U.S. patent application Ser. No. 11/200,863, entitled “Contact Lens Extraction/Hydration Systems and Methods of Reprocessing Fluids Used Therein”; U.S. patent application Ser. No. 11/200,862, entitled “Contact Lens Package”; and U.S. Patent Application No. 60/707,029, entitled “Compositions and Methods for Producing Silicone Hydrogel Contact Lenses”.
A number of publications and patents have been cited hereinabove. Each of the cited publications and patents are hereby incorporated by reference in their entireties.
While this invention has been described with respect to various specific examples and embodiments, it is to be understood that the invention is not limited thereto and that it can be variously practiced within the scope of the following claims.
Number | Name | Date | Kind |
---|---|---|---|
3935291 | Jackson | Jan 1976 | A |
4592887 | Bando et al. | Jun 1986 | A |
4761069 | Truong et al. | Aug 1988 | A |
4868397 | Tittel | Sep 1989 | A |
4872405 | Sterman | Oct 1989 | A |
5036971 | Seden et al. | Aug 1991 | A |
5080839 | Kindt-Larsen | Jan 1992 | A |
5094609 | Kindt-Larsen | Mar 1992 | A |
5114455 | Hirota et al. | May 1992 | A |
5120499 | Baron | Jun 1992 | A |
5144144 | Borovsky | Sep 1992 | A |
5158718 | Thakrar et al. | Oct 1992 | A |
5204126 | Singh et al. | Apr 1993 | A |
5252056 | Hörner et al. | Oct 1993 | A |
5292350 | Molock et al. | Mar 1994 | A |
5407627 | Schiller et al. | Apr 1995 | A |
5488815 | Abrams et al. | Feb 1996 | A |
5540410 | Lust et al. | Jul 1996 | A |
5573108 | Hamilton et al. | Nov 1996 | A |
5593620 | Galas | Jan 1997 | A |
5597519 | Martin et al. | Jan 1997 | A |
5640980 | Keene et al. | Jun 1997 | A |
5648024 | Galas | Jul 1997 | A |
5687541 | Martin et al. | Nov 1997 | A |
5690866 | Andersen et al. | Nov 1997 | A |
5693268 | Widman et al. | Dec 1997 | A |
5704468 | Lust et al. | Jan 1998 | A |
5749205 | Edwards et al. | May 1998 | A |
5759318 | Galas | Jun 1998 | A |
5762081 | Keene et al. | Jun 1998 | A |
5804107 | Martin et al. | Sep 1998 | A |
5820895 | Widman | Oct 1998 | A |
5836323 | Keene et al. | Nov 1998 | A |
5849209 | Kindt-Larsen et al. | Dec 1998 | A |
5849222 | Jen et al. | Dec 1998 | A |
5850107 | Kindt-Larsen et al. | Dec 1998 | A |
5882698 | Su et al. | Mar 1999 | A |
5894002 | Boneberger et al. | Apr 1999 | A |
5895192 | Parnell, Sr. et al. | Apr 1999 | A |
5935492 | Martin et al. | Aug 1999 | A |
5965172 | Wang et al. | Oct 1999 | A |
6033603 | Lesczynski et al. | Mar 2000 | A |
6039899 | Martin et al. | Mar 2000 | A |
6071440 | Wang et al. | Jun 2000 | A |
6113817 | Herbrechtsmeier et al. | Sep 2000 | A |
6149842 | Lally et al. | Nov 2000 | A |
6180032 | Parnell, Sr. et al. | Jan 2001 | B1 |
6183705 | Chang | Feb 2001 | B1 |
6193369 | Valint, Jr. et al. | Feb 2001 | B1 |
6257547 | Togo et al. | Jul 2001 | B1 |
6288852 | Cameron | Sep 2001 | B1 |
6310116 | Yasuda et al. | Oct 2001 | B1 |
6315929 | Ishihara et al. | Nov 2001 | B1 |
6359024 | Lai | Mar 2002 | B2 |
6364934 | Nandu et al. | Apr 2002 | B1 |
6405993 | Morris | Jun 2002 | B1 |
6428723 | Lesczynski et al. | Aug 2002 | B1 |
6432217 | Baxter et al. | Aug 2002 | B1 |
6444145 | Clutterbuck | Sep 2002 | B1 |
6465538 | Lai | Oct 2002 | B2 |
6475410 | Nakagawa | Nov 2002 | B1 |
6511617 | Martin et al. | Jan 2003 | B1 |
6531432 | Molock et al. | Mar 2003 | B2 |
6551531 | Ford et al. | Apr 2003 | B1 |
6565776 | Li et al. | May 2003 | B1 |
6592356 | Lust et al. | Jul 2003 | B1 |
6627124 | Herbrechtsmeier et al. | Sep 2003 | B1 |
6638362 | Dobner et al. | Oct 2003 | B2 |
6638451 | Hagmann et al. | Oct 2003 | B1 |
6708397 | Parnell, Sr. et al. | Mar 2004 | B2 |
6719929 | Winterton et al. | Apr 2004 | B2 |
6790873 | Tomono et al. | Sep 2004 | B2 |
6867245 | Iwata et al. | Mar 2005 | B2 |
20020016383 | Iwata et al. | Feb 2002 | A1 |
20020020634 | Fortune | Feb 2002 | A1 |
20020046958 | Lipscomb et al. | Apr 2002 | A1 |
20020137811 | Turek et al. | Sep 2002 | A1 |
20020163619 | Matsuzawa et al. | Nov 2002 | A1 |
20020185763 | Pegram et al. | Dec 2002 | A1 |
20030000028 | Molock et al. | Jan 2003 | A1 |
20030031746 | Calvin et al. | Feb 2003 | A1 |
20030049346 | Calvin et al. | Mar 2003 | A1 |
20030062640 | Ansell et al. | Apr 2003 | A1 |
20030090014 | Heinrich et al. | May 2003 | A1 |
20030108637 | O'Dunlaing et al. | Jun 2003 | A1 |
20030125498 | McCabe et al. | Jul 2003 | A1 |
20030134132 | Winterton et al. | Jul 2003 | A1 |
20030160343 | Hodgkinson | Aug 2003 | A1 |
20030164562 | Li et al. | Sep 2003 | A1 |
20030164563 | Calvin et al. | Sep 2003 | A1 |
20030197833 | Hiratani et al. | Oct 2003 | A1 |
20030203066 | Lust et al. | Oct 2003 | A1 |
20030222362 | Indra et al. | Dec 2003 | A1 |
20040000732 | Spaulding et al. | Jan 2004 | A1 |
20040031701 | Peck et al. | Feb 2004 | A1 |
20040074525 | Widman et al. | Apr 2004 | A1 |
20040075039 | Dubey et al. | Apr 2004 | A1 |
20040075182 | Gobron | Apr 2004 | A1 |
20040075807 | Ho et al. | Apr 2004 | A1 |
20050171232 | Ford et al. | Aug 2005 | A1 |
20060097415 | Watterson et al. | May 2006 | A1 |
Number | Date | Country |
---|---|---|
0 908 476 | Apr 1999 | EP |
64-084219 | Mar 1989 | JP |
5-337957 | Dec 1993 | JP |
11-320699 | Nov 1999 | JP |
2000-162555 | Jun 2000 | JP |
2002-137230 | May 2002 | JP |
WO 0115497 | Mar 2001 | WO |
Number | Date | Country | |
---|---|---|---|
20070035052 A1 | Feb 2007 | US |