Casey Eye Institute - Patient Services

Recent progress in molecular and cellular biology has opened the door to a new generation of treatments designed to protect, replace or repair eye cells that are damaged by disease. Part of this research involves the development of improved methods of delivering the therapeutics to the targeted area.

Experimental Anti-Angiogenic Drugs

A number of other pharmacological agents remain under investigation for their effects on inhibiting growth of new vessels in wet AMD. These include the VEGF trap, small interfering RNA drugs and squalamine lactate. Anecortave acetate (Retaane), a steroid compound, is being studied not only as a means of inhibiting newly formed blood vessels, but also for its potential to prevent wet AMD in high-risk eyes.

Neuroprotective Agents

Another promising class of biomedicines contains neuroprotective proteins that slow or prevent the degeneration of photoreceptor cells in the retina. Many of these experimental therapies are being tested in patients with retinitis pigmentosa (RP), with the hope that they can then be applied to AMD patients.

Encapsulated Cell Technology

Casey has been selected as a participating center for the first Phase II/III study of a protein molecule called CNTF. This biomedicine is delivered to the back of the eye via a time release system called Encapsulated Cell Technology (ECT). A device the size of a grain of rice is loaded with these helpful proteins and then implanted inside the vitreous cavity. It enables the medication to be targeted to where it�s most needed over a sustained period. Although the trial is primarily aimed at individuals with RP, an arm of the study will test the therapy on a limited number of patients with AMD.

Casey investigators will also be involved in the first human clinical trial of a neuroprotective factor conveyed by injection in the space behind the retina. The Phase I study will evaluate the drug�s safety in RP patients and may be tested on AMD patients in subsequent trials.

Cell-Based Therapies

Scientists at Casey and elsewhere are studying the use of stem cells to replace photoreceptor cells lost to retinal disease. Casey recently received the first installment of a $4.8 million grant from the California-based Lincy Foundation to pursue translational stem-cell research for AMD. The goal of this research project is to learn if these undifferentiated cells can ultimately restore vision in wet or dry AMD by rescuing or replenishing retinal cells. These experiments will help determine where these cells should be introduced in the eye and how to translate discoveries in the lab to humans.

Gene Therapy

Casey scientists have completed a preliminary study of the first gene therapy trial for macular disease in the U.S. The multi-center clinical trial found that injecting a gene directly into the eye to inhibit blood vessel growth was safe and well tolerated and may be able to halt the progression of wet AMD. The study drug stimulates production of the PDF gene, which regulates the formation of blood vessels. Investigators currently are analyzing the study data to determine if additional trials will be conducted.

Surgical Therapy

In recent years, intraocular surgery has been used to remove blood and new blood vessels from behind the retina in patients with AMD. While often technically successful, improvement in the visual outcome has not been demonstrated. The Casey Eye Institute was one of 25 clinical centers evaluating this approach in the National Eye Institute-funded Subretinal Surgery Trials. Results of the study, reported in 2004, found that submacular surgery was not significantly beneficial for patients with extensive bleeding under the retina or new blood vessel growth. This form of therapy is not generally used except in highly selected cases.

Surgical approaches also include techniques in which the retina is moved, or relocated slightly, to an area where the underlying tissues are healthier. Following the surgical translocation procedure, a laser is used to destroy the new blood vessels in the hope of preventing them from growing back to their original location beneath the center of the macula. Complications are relatively common and this treatment is not routinely performed at most centers.

Retinal Cell Transplantation

Increasing progress is being made with retinal and retinal pigment epithelial cell transplantation. Certain transplanted cells have been shown to survive in the macula, but restoration of function with improved vision has yet to occur.

Rheotherapy

Rheotherapy, a form of therapeutic blood filtration, has also been proposed as a treatment for AMD. However, recent clinical trial results have failed to provide evidence of efficacy.

Other Treatments

Because AMD is so widespread and treatment options limited, numerous "cures" are now on the market, claiming to restore vision. Some of these remedies include microcurrent stimulation, various herbs and magnets. At this time, we do not recommend these and other unproven treatments because they have not undergone rigorous scientific testing. If you are considering using such a treatment or product, ask for more information or consult a medical doctor, pharmacist or other knowledgeable health care professional.