Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Patent
1997-06-05
2000-06-13
Merriam, Andrew E. C.
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
536 551, 536 552, 351160H, 264 17, G02B 104
Patent
active
060750669
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
This invention relates to materials to be worn on the eyeball comprising a photocured crosslinked-glycosaminoglycans, particularly to a material to be worn on the eyeball which is transparent and has a shape of semi-spherical surface with excellent dimensional stability (shape stability) and high surface wettability.
BACKGROUND ART
Contact lenses (to be referred to as "CL" hereinafter) are roughly divided into hard contact lenses (to be referred to as "HCL" hereinafter) and soft contact lenses (to be referred to as "SCL" hereinafter) depending on the flexibility of raw materials. The conventional HCL raw materials cannot be applied to continuous wearing for a prolonged period of time because of their impermeability of oxygen which is necessary for the metabolism of corneal tissues. Hence, raw materials having high oxygen permeability have been developed and are now popularly applied to continuously wearable HCL having high oxygen permeability. With regard to the raw materials of SCL, on the other hand, hydrous high polymers having high oxygen permeability have been used and are now popularly applied to continuously wearable highly hydrous SCL. However, since the contact time of the CL material with ophthalmic tissues such as cornea, conjunctiva and the like becomes long as the continuous wearing of CL is prolonged, it has been desired to develop a material having more high tissue compatibility (biocompatibility with ophthalmic tissues).
Collagen has been known as a CL material having tissue compatibility (JP-B 62-42487, U.S. Pat. No. 4,223,984, U.S. Pat. No. 4,260,228, U.S. Pat. No. 4,264,155) and commercialized as Collagen Lens (Bausch & Lomb, U.S.A.) (the term "JP-B" as used herein means an "examined Japanese patent publication"). Also, JP-B 62-42487 discloses a CL which is formed after mixing collagen with a chondroitin sulfate or the like mucopolysaccharide (glycosaminoglycan). However, collagen, which is a protein, has a disadvantage of having antigenicity. The eye is highly sensitive especially against exogeneous material and apt to cause inflammations when the exogeneous material has antigenicity.
In addition, various raw materials of the CL and the like materials to be worn on the eyeball have been known, such as a raw material which comprises a polyvinyl alcohol-based gel containing a chondroitin sulfate or the like acid polysaccharide (JP-B 51-11139), chitin or chitosan (JP-A 56-94322, JP-W 61-501729, JP-A 63-50816, JP-A 4-176459, JP-A 4-275346 and the like), glucomannan (JP-A 5-163384), silk fibroin (JP-A 5-313105) and the like (the term "JP-A" as used herein means an "unexamined published Japanese patent application", and the term "JP-W" as used herein means an "unexamined published Japanese international patent application"). However, all of such raw materials have a problem in terms of tissue compatibility, because their principal components do not originate from biological materials(vertebrate).
As described above, raw CL materials which contain glycosaminoglycan are known, but no CL which substantially comprises glycosaminoglycan alone.
An object of the present invention is to provide materials to be worn on the eyeball having a semi-spherical shape, such as contact lenses for use in the visual acuity correction or medical treatment, cornea-protecting materials (corneal bandages) or controlled drug release contact lenses, which comprise, as their main component, a glycosaminoglycan (mucopolysaccharide) existing in the living body as an extracellular matrix component of connective tissues and the like, and satisfy various requirements such as dimentional stability, transparency, surface wettability, tissue compatibility (non-irritation, safety), oxygen permeability and the like.
DISCLOSURE OF THE INVENTION
The present invention relates to surface compatible in shape with the mammalian eyeball and having biological and surface-physical compatibilities with ophthalmic tissues, which comprises, as a main component, a substantially transparent photocured crosslinked-glycos
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Hiroshi Nakao et al., Folia Ophthalmologica Japonica, 45(5), 484-489 (1994) Month? International Search Report.
J.P.F. Strachan,"Further Comments on the Fitting of Spherical Hydrophilic Lenses . . . ," The Australian Journal of Optometry, 1975, pp. 11-22.
Matsuda Takehisa
Nakao Hiroshi
Merriam Andrew E. C.
Seikagaku Kogyo Kabushiki Kaisha
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