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  • Collagen Corneal Shields

    Has anyone gathered any experience with this option or does anyone know if those are commercially available? It looks like they are very rare and you can only get them in clinics after injuries.

    Although this article is quite old, it sounds interesting and I wonder if there is any research going on as to a possible standard dry eye treatment.

    Maybe we have someone here from Chicago who could go check them out?

    Collagen Corneal Shields
    Reviewed:
    Last Updated: 11/01/88
    Created: 11/01/88
    Revised:

    The collagen corneal shield is a newly developed, potentially multipurpose ophthalmic lens, which is made of a natural protein. Collagen, in humans, is one of the most widespread and important proteins found in the body. It is an essential component of joints, skin, and the surface of the eye. Collagen is the major component of the white sclera and the clear cornea, both of which make up the outer coat of the eyeball. Additionally, collagen is an essential element for healing wounds anywhere in the body, including the eye.

    Since collagen is a natural, widely available protein involved in the support and protection of vital structures, many researchers have tried to use extraneous collagen to protect the surface of the eye in a variety of disease states. The pioneer in this research is Dr. Svyatoslav Fyodorov of the Soviet Union. Dr. Fyodorov was able to extract collagen from porcine sclera and shape it in the form of a contact lens that can easily be placed on the surface of the eye. Early experience with his collagen "contact lens" showed that it was able to protect the ocular surface and also that it was dissolvable. It seemed that naturally occurring enzymes in the tear film caused the collagen contact lens to dissolve over a period of time.

    Bausch & Lomb Pharmaceuticals, a division of Bausch & Lomb, Inc. (an international contact lens and ophthalmic care company) acquired the rights to develop and market these collagen contact lenses, now known as BioCora collagen shields. After much research, Bausch & Lomb has been able to produce the shields in a reproducible manner and in a variety of shapes and thickness. Additionally, of great significance, Bausch & Lomb has been able to slightly alter the biochemical composition of the shields and thereby vary their dissolution rate. Shields have now been produced to dissolve in 6, 12, 24, 48, and 72 hours and even one week.



    What are the practical uses of collagen shields?
    The most obvious use is for ocular surface lubrication. Again, collagen is a naturally occurring protein that is totally safe for use on and in the body. As these shields dissolve, they become gel-like and eventually liquefy. Early studies have demonstrated that this gel-like dissolution can be very helpful to individuals who do not produce sufficient quantities of tears. (This "dry eye" condition can be quite damaging to the ocular surface.) These patients are often required to place drops of artificial tears into their eyes every 30 or 60 minutes. Early research has shown that the collagen shield can reduce the necessity for this frequent and inconvenient administration of artificial tears. The bioCor collagen shield is currently available to physicians for use among patients with dry eye syndromes.
    Other potential uses for the collagen shields are being actively investigated by Bausch & Lomb Pharmaceuticals as well as by several research organizations around the country, including the UIC Eye Center. One of the most exciting areas that has stemmed from these investigations is drug delivery. The collagen shield, it has been found, can serve as a "sponge" to collect medications that are placed in drop form on the surface of the eye and then slowly release them over a period of time as the shield dissolves. A number of laboratory and clinical studies are beginning to show that the drug concentrations released from the collagen shield are high enough to be effectively used in treating a variety of diseases (including infections and inflammation of the ocular surface.) This "time release" of topical medications to the eye has obvious benefits for use in the several potentially blinding diseases that require frequent administration of drop medications. The potential for an ophthalmologist to place a shield with a drug on the surface of a patient's eye, as opposed to asking the patient to place frequent drops on the eye over long periods of time, is a revolutionary concept. Collagen shields have not yet been formally approved by the Food and Drug Administration for this use.

    However, clinical studies have begun or will soon begin to investigate the usefulness and safety of collagen shields for the delivery of medications in several centers around the country, including the UIC Eye Center.

    Another potential use for the collagen shields is that of ocular surface protection. In nearly all types of eye surgery, the surface coat (the sclera or the cornea) must be incised to allow access to the interior part of the eye. How this incision heals is of crucial importance to the success of the surgery. A basic necessity for successful healing of either surgical incisions or wounds created by trauma is that the wound must be adequately protected from the external environment as well as from the blinking action of the eyelids. This is why patients who have eye surgery or who have had trauma to the eyes are required to wear a patch in the early phases of healing. In addition to patching therapy, ophthalmologists have used special soft contact lenses (called "bandage" contact lenses) to provide protection to the surface of the eye. These bandage contact lenses are expensive and have been associated with some complications, particularly when they are used over a long period of time. As the collagen shield contains a naturally occurring protein, it would appear to be an ideal alternative to bandage contact lenses for protecting the eye. This area of research is in its infancy and is being conducted primarily here at the UIC Eye Center. Preliminary results have shown that the collagen shield can indeed provide an adequate protective environment to allow healing of surgical and traumatic wounds to the eye.

    Another intriguing possibility that we are actively researching at the UIC Eye Center is whether the nature of the shield itself could improve wound bearing. As noted earlier, collagen is an essential part of the natural wound healing process. It is conceivable that the collagen in the shield could be incorporated (as the shield dissolves) into a healing wound on the surface of the eye and have beneficial effects.

    The future for collagen shields is highly promising. The characteristics of providing ocular lubrication, protection, and drug delivery and the potential for better and faster wound healing may eventually make these shields a standard part of ophthalmic practice.

    The UIC Eye Center is playing an important role in the determination of the effectiveness and safety of BioCor collagen shields in a variety of eye diseases. With the help of Bausch & Lomb Pharmaceuticals, a corneal research laboratory has been created in the Eye and Ear Infirmary of the UIC Eye Center to investigate the wound healing and drug delivery aspects of these shields.

    "Eye Facts" is intended as an informational series and should not be used as a substitute for medical advice.

    The Comprehensive Ophthalmology Service is located in the Eye and Ear Infirmary at 1855 W. Taylor Street, Chicago IL 60612. For eye appointments, call (312) 996-4356.
    Dysfunctional Tear Syndrome ("Dry Eye Disease") is a bane of modern society.

  • #2
    Collagen Lenses - amendment

    This is a more recent abstract from 2002:
    Application of collagen shield as drug delivery system to human eye
    Collagen is regarded as one of the most useful biomaterials. The excellent biocompatibility and safety due to its biological characteristics, such as biodegradability and weak antigenecity, made collagen the primary resource in medical applications.
    One of the main applications of collagen as drug delivery systems are collagen shields in ophthalmology,
    Eye-drops are the conventional dosage forms that account for 90% of currently accessible ophthalmic formulations. Despite the excellent acceptance by patients, one of the major problems encountered is rapid precorneal drug loss. To improve ocular drug bioavailability, there is a significant effort directed towards new drug delivery systems for ophthalmic administration.
    Collasomes show promise in drug delivery system to human eye. They are first fabricated from porcine scleral tissue, which bear a collagen composition similar to that of the human cornea. The shields are hydrated before they are placed on the eye, having been stored in a dehydrated state. Typically the drug is loaded into the drug solution for a period of time prior to application. Once in the eye, shields are hydrated by tear fluids, and then soften and form a clear, pliable, thin film approximately 0.1 mm in thickness, with a diameter of 14.5 mm and a base curve of 9 mm that conforms to the corneal surface. Designed to slowly dissolve within 12, 24, or 72 h. It has been developed as a new continuous-delivery system for drugs that provide high and sustained levels of drugs to the cornea. Despite findings that suggest the superiority of shields in drug delivery, there are a number of difficulties related to the design and use of collagen shields. Hydrated shields are difficult to handle and cannot be inserted by patients themselves. Collagen shields are designed to be inserted in a physician’s office, often produce some discomfort, and interfere with vision. Shields are not individually fit for each patient, as are soft contact lenses, and therefore, comfort my problematic and expulsion of the shield may occur.
    Kaufman et al. have developed a new drug delivery system, collasomes. They combined collagen pieces or particles and a viscous vehicle that could be instilled beneath the eyelid, thereby simplifying application and reducing the blurring of vision. The collasomes were well tolerated, and because the collagen particles are suspended in carrier vehicles, they could be instilled safely and effectively by patients in much the same fashion as drops or ointments.
    SOURCE: John Hopkins University, Baltimore (Maryland, USA)
    Dysfunctional Tear Syndrome ("Dry Eye Disease") is a bane of modern society.

    Comment


    • #3
      Thanks Phillip. This has been some interesting reading...seems the collagen shields haven't really become popular because of discomfort? I'm not really sure as this is a new topic to me. I did find a couple of links that I found interesting:

      http://www.ddcr.com/articles/ddcr_s2002_article6.pdf
      Near the end there is a bit about collagen shields. Minidiscs, I think.

      And here is a link to Oftalmo.com
      http://www.oftalmo.com/seo/2003/02feb03/02.htm

      "Other inserts, both erodible and nonerodible (as e.g. medicated contact lenses, collagen shields, the Minidisc® etc.) have also been shown capable to diminish the systemic absorption of ocularly applied drugs, as a result of a decreased drainage into the nasal cavity, which is one of the major systemic absorption sites of topical ocular medications. Another potential advantage of insert therapy is the possibility of promoting non-corneal drug penetration, thus increasing the efficacy of some hydrophilic drugs which are poorly absorbed through the cornea. However, in spite of great expectations, attention on inserts has gradually waned in recent years."
      Cindy

      "People may not always remember exactly what you said or what you did, but they will always remember how you made them feel." ~ Unknown

      Comment


      • #4
        Collagen Shields

        Cindy,

        in my opinion, we should definitely try to find out what the current research status on these things is. Let's be blunt: A protective shield made from collagen and soaked in liquid, that self-dissolves within 24hrs. and by doing so lubricates the ocular surface! That does sound very helpful for people like us...

        The head reseracher is actually a German MD working in the US. Unfortunately, he used to work in New Orleans until the recent events.

        Anyway, his name is:

        Kaufman HE.

        LSU Eye Center, Health Sciences Center, Louisiana State University School of Medicine, 2020 Gravier Street, New Orleans, LA 70112, USA. hkaufm@ksuhsc.edu

        If you care to run a search for collagen shields on the National Center For Biotechnology Information (http://www.ncbi.nlm.nih.gov/) you will easily find a lot of work about collagen shields and their clinical applications. Mr. H.E. Kaufmann has also been studying them especially for DES!

        I haven't contacted him yet because I think it might be inappropiate at this time in New Orleans..

        What do you think?

        BRGDS

        Philipp
        Dysfunctional Tear Syndrome ("Dry Eye Disease") is a bane of modern society.

        Comment


        • #5
          What do you think?
          I think if you want to get in touch with him, you should try now. New Orleans is "going." Restaurants are open, they are trying to attract some tourism, etc. Life is far from normal, and lots of suffering for a long time to come. But certainly no doctor will have stopped his work unless he was injured or some catastrophe.

          It all goes back to money. If something cannot make it financially, you are not going to have many backers. You are fairly new to the "post-op" business. The older folks have seen some things come and go a couple of times. Please try and contact this dr and let us know! I'd love to hear his response. PS. The sclerals are fine!
          Don't trust any refractive surgeon with YOUR eyes.

          The Dry Eye Queen

          Comment


          • #6
            Money Making

            Lucy

            I know exactly what you are talking about and have had endless conversations with my UK scleral lens optometrist who is facing that very problem. His lenses could bring relief to many people but without industy and insurance backing them it is only something for the rich guys again...

            Anyway, I think any working dry eye treatment has the potential to make the patent-holder wealthy so I remain optimistic :-)

            Will contact my german fellow doc in New Orleans and keep you posted!

            Philipp

            PS: Their web page is on again: http://www.lsu-eye.lsuhsc.edu/
            Turns out that there is aslo a lot of dry eye research going on at this place!
            Last edited by Philipp_from_Germany; 24-Nov-2005, 07:26.
            Dysfunctional Tear Syndrome ("Dry Eye Disease") is a bane of modern society.

            Comment


            • #7
              and here is the answer:

              "Patients with dry eye did not like the shields covering the cornea in the few I tried"

              Herb Kaufman
              Dysfunctional Tear Syndrome ("Dry Eye Disease") is a bane of modern society.

              Comment


              • #8
                Philipp,

                Darn. Thanks for trying. I was looking for some good news this week on the dry eye front. I've been "blue" about my very uncomfortable eyes lately. Some day, right??!

                Diana
                Never play leapfrog with a unicorn.

                Comment

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