Silicone hydrogel contact lens

Abstract

Ophthalmically compatible contact lenses include lens bodies configured for placement on a cornea of an animal or human eye. The lens bodies are made of a hydrophilic silicon-containing polymeric material. The lens bodies have oxygen permeabilities, water content, surface wettabilities, flexibilities, and / or designs to be worn by a lens wearer even during sleep. The present lenses can be worn on a daily basis, including overnight, or can be worn for several days, such as about thirty days, without requiring removal or cleaning.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Application No. 60 / 604,961, filed Aug. 27, 2004 and U.S. Provisional Application No. 60 / 621,525, filed Oct. 22, 2004, the contents of which in their entireties are hereby incorporated by reference.BACKGROUND OF THE INVENTION [0002] The present invention relates to contact lenses which are wearable, on a continuous basis, for extended periods of time. In particular, the invention relates to flexible, hydrophilic silicon-containing contact lenses which have advantageous combinations of properties. [0003] Contact lenses are fundamentally classified into soft and hard type lenses. Hard contact lenses are literally hard and can be somewhat uncomfortable to wear. On the other hand, soft contact lenses are more comfortable to wear, but are commonly removed from the eye at the end of each day. Soft contact lenses are classified as hydrogel lenses and non-hydrogel lenses. [0004] Conventiona...

AI Technical Summary

Benefits of technology

[0015] New contact lenses have been invented. For example, contact lenses which comprise a hydrophilic silicon-containing polymeric component (e.g., silicone hydrogel contact lenses) have been invented. The present lenses can be understood to be associated with one, two, or more of the following features, a natural wettability (e.g., an untreated surface wettability), a high Dk, a high water content, a low modulus, and designs that facilitate wearing the contact lenses with reduced discomfort. For example, the present lenses have one or more of the foregoing properties when compared to existing silicone hydrogel contact lenses. Or, stated differently, the present lenses have different values of one or more of the foregoing properties. The properties of the present lenses lead to reduced disomfort to the lens wearer wearing the present contact lenses compared to existing silicone hydrogel contact lenses.

[0019] The present silicone hydrogel contact lenses may comprise surfaces that have a greater wettability than existing silicone hydrogel contact lenses, such as those silicone hydrogel contact lenses described herein. As understood by persons of ordinary skill in the art, the wettability of a contact lens surface can be determined by measuring the wetting angle using a method, such as the sessile drop method. Lower wetting angles correspond to enhanced surface wettability. For purposes of comparison, existing silicone hydrogel contact lenses, such as those described herein, have surfaces that provide a wetting angle from about 60° to about 110°. The present silicone hydrogel contact lenses may comprise surfaces, such as the anterior and / or posterior surface, that have a wetting angle less than 60°. In certain embodiments, the present silicone hydrogel contact lenses have surfaces that have a wetting angle less than about 50°. In further embodiments, the present silicone hydrogel contact lenses have surfaces that have a wetting angle of about 30°. At least one example of the present contact lenses has a surface that has a wetting angle less thn 40°. The present contact lenses with the lower wetting angle, and therefore, enhanced surface wettability, have higher Dks, higher water contents, and / or lower modulus compared to existing silicone hydrogel contact lenses, as discussed herein.

[0020] The present lenses may provide improvement or enhancement in patient comfort compared to existing silicone hydrogel contact lenses, as discussed herein. For example, whereas only about 15% of patients wearing existing silicone hydrogel contact lenses reported satisfactory comfort wearing the lenses, about 40% of patients wearing the present silicone hydrogel contact lenses reported satisfactory comfort wearing the lenses.

[0022] The present lenses are hydrophilic, and have unique and advantageous combinations of properties as described herein. The combinations of properties are helpful in evaluating appropriate conditions for wearing the present lenses. For example, certain combinations of properties, such as high water content, relatively lower Dk, and low modulus may be desirable or acceptable for daily wear silicone hydrogel contact lenses, such as lenses that can be worn overnight without cleaning, but that are typically disposed of on a daily basis. Other combinations of properties, such as high Dk, high water content, and low modulus may be effective in facilitating the use of such lenses in continuous or extended wear applications, such as for more than one night, such as for at least about five days, for example about two weeks or more, or at least about one month. The present contact lenses can be relatively easily and cost effectively produced. Using such lenses provides advantages, such as, vision correction with reduced lens handling and maintenance, continuous or extended wearing of contact lenses, while being ophthalmically compatible and providing for wearer comfort and safety.

[0025] In one embodiment, the lens bodies of the present contact lenses may have a combination of properties, including an effective or appropriate ionoflux to substantially inhibit, or even substantially prevent, corneal staining, for example, corneal staining more severe than superficial or moderate corneal staining, after the contact lens is worn continuously on a cornea of a human or animal eye for 8 hours or more, for example, for about 1 day, or about 5 days, or about 10 days, or about 20 days or about 30 days or longer.

[0028] The present contact lenses include a lens body comprising a hydrophilic silicon-containing polymeric material. In one embodiment, the polymeric material comprise units from a silicon-containing monomer, for example, from two silicon-containing macromers having different molecular weights, and preferably different chemical structures. Such an embodiment may be particularly useful for continuous wear silicone hydrogel contact lenses, such as silicone hydrogel contact lenses that can be worn continuously for about 30 days. In another embodiment, the present contact lenses comprises only one silicon-containing macromer having a relatively high molecular weight. This embodiment, that is the embodiment comprising one silicon-containing macromer may be particularly useful for daily wear silicone hydrogel contact lenses that can be worn while sleeping, but that are typically discarded on a daily basis.

Problems solved by technology

Hard contact lenses are literally hard and can be somewhat uncomfortable to wear.

However, it appears that the polarographic techniques may not provide accurate measurements for high Dk silicone hydrogel contact lenses, such as silicone hydrogel contact lenses having a Dk greater than about 100 barrers.

Furthermore, existing silicone hydrogel contact lenses do not have desirable surface wettabilities.

One problem that arises in extended or continuous wear contact lenses is adhesion of the lens to the cornea during lens wearing which can result in wearer discomfort, eye irritation, corneal staining and / or other damage to the eye.

Although lenses with high water contents are softer and more comfortable to wear, such prior art lenses may not have one or more properties useful to provide comfortable and safe wearing of the contact lenses.

For example, existing contact lenses may not have a desirable Dk, a desirable surface wettability, a desirable modulus, a desired design, and / or a desirable water content.

Images