We live in an age of technological miracles. But many "high tech" solutions that solve one problem end up causing other problems. Many modern pharmaceuticals, for example, are highly effective -- but also produce potentially devastating side effects.

Corticosteroids are a case in point. When using steroids to treat back-of-the-eye diseases such as uveitis, delivering the drug to the affected area has been a major problem because of the side effects that can occur during the delivery process:

�       Periocular injections risk globe perforation, orbital fibrosis and ptosis.

�       Systemic treatment with corticosteroids over an extended period can have drastic, life-altering side effects throughout the body.

�       Topical treatment with corticosteroids is ineffective because of limited penetration.

In addition, it's difficult or impossible to maintain a consistent level of medication using any of these delivery methods. This can mean loss of vision, despite the treatment. (These treatment methods may also create a serious financial burden for the patient -- as much as $10,000 a year in some cases.)

Getting to the heart of the matter

Thanks to a new technology currently being developed and tested by Bausch & Lomb, these problems -- at least in the treatment of many back-of-the-eye diseases -- may soon become a thing of the past.

Envision TD is a patented system that delivers sustained, consistent, low levels of medication directly to the affected area of the eye. A tiny insert, consisting of a small quantity of medication encased in non-biodegradable, inert polymer coatings, is placed inside the eye near the diseased tissue. One side of the casing is permeable, allowing the medication to slowly leach out into the vitreous. Depending on the medication, a single insert may be able to work for as long as 18 years.

Envision TD technology was developed by Control Delivery Systems Inc. (CDS), a privately held company in Massachusetts. It was first used in the product Vitrasert, which was approved in 1996 to treat CMV retinitis, a condition associated with late-stage AIDS that often leads to blindness. Vitrasert releases ganciclovir (Cytovene) directly to the diseased area of the eye over a period of 6 to 8 months. It has successfully treated CMV retinitis in more than 5,000 patients.

Bausch & Lomb licensed Vitrasert in 1997. Then, in June, 1999, Bausch & Lomb and CDS formed a long-term partnership to use this technology to develop and market other implantable products.

Treating posterior uveitis

Currently, Bausch & Lomb and CDS are testing a new Envision TD insert designed to treat posterior uveitis. This insert contains fluocinolone acetonide, a powerful synthetic anti-inflammatory drug. The device is sutured to the inside of the sclera. (See illustration, right.)

A phase I/II clinical study involving seven eyes in five patients, conducted by Glenn A. Jaffe, M.D., a principal investigator from Duke University Eye Center in N.C., has shown very promising results. All five patients had severe uveitis and were either unable to tolerate traditional therapy or failed to respond to it. After having the fluocinolone insert implanted, all seven eyes were stabilized; four eyes showed improvement in vision. (The mean visual acuity of the eyes studied increased from 20/186 to 20/53.)

All five patients were able to drastically reduce their use of systemic anti-inflammatory medication, and they experienced a corresponding reduction in side effects.

Changing lives

The devastating side effects of systemic steroids are well illustrated by one participant in the study who had been taking more than 10 medications a day to manage steroid side effects such as osteoporosis, drastic changes in physical appearance and interference with mental clarity. Despite this onerous regimen, the patient's vision was extremely poor.

In contrast, the fluocinolone insert enabled him to reduce systemic steroids to a bare minimum, eliminate the other medications and undergo cataract surgery. His vision, overall health and physical appearance have all improved dramatically, and he has returned to living a normal life for the first time in many years.

Another participant also experienced clear vision for the first time in years. "This patient had never been able to see her child clearly -- even when she gave birth. During the study her inflammation finally quieted down, and she was able to see her son's face for the first time," relates Dr. Jaffe. "She still cries when she talks about it."

Looking forward

Barry Butler, director of new product marketing at Bausch & Lomb, says that development of this technology is a high priority at B&L. "We believe this technology will have a tremendous impact. Back-of-the-eye diseases have often been poorly treated -- or not treated at all. Envision TD technology has produced better outcomes than previous treatments, and dramatically reduced the side effects of those treatments. The potential benefits for patients are enormous.

"Eventually, we hope to use this technology to treat a variety of sight-threatening diseases, including age-related macular degeneration and diabetic macular edema."

According to Bausch & Lomb, treating uveitis with Envision TD technology should cost significantly less than previous treatment options. (How much less won't be determined until the fluocinolone insert is approved and ready to market.)

Because of the promising early results and the likelihood that this technology will help meet an unmet medical need, the company has received "fast track" designation from the FDA for the uveitis treatment. B&L plans to begin phase III clinical trials in the United States, Japan and Europe within the next several months.

Are you aware of new products or technology that have made (or are likely to make) a significant difference in practice? Contact Christopher Kent at kentcx@boucher1.com to find out about possible coverage in a future issue OPHTHALMOLOGY MANAGEMENT