Eye Drops for Macular Degeneration?

As advancement in macular degeneration research continues, so too have the drug delivery options for symptom management as well as slowing disease progression. Now, instead of painful injections which is a common part of a variety of these treatments, less invasive choices may be available.

New drug delivery options for macular degeneration therapy are now backed by increasingly positive research results. Some hope these new advancements may do away with injections altogether. An additional benefit is more willingness for patients, especially those with age-related macular degeneration (AMD), to seek and continue these pain-free treatments.

Current Delivery

Common injections for macular degeneration and other retinal disease symptoms include:

• Transscleral – Applied to the white of the eye
• Intravitreal – Injected directly into the eye

These injections can create various problems for patients, especially those with AMD which are often elderly and challenged by other health issues.

Problems with injections may include:

• Pain
• Infection
• High cost
• Discomfort
• Delicate recovery
• Physical exhaustion
• Invasive anesthesia
• Continuous transport and chaperon scheduling
• Potential for possible blindness from complications

The study, ‘Ophthalmic Drug Delivery Systems for the Treatment of Retinal Diseases’ from combined data published in Investigative Ophthalmology and Visual Science stated,

“Monthly injections of anti-VEGF therapies to maximize visual potential are a significant treatment burden on the patient. As a result, the need for better treatments for AMD remains.”

Now, new drug delivery options for macular degeneration have addressed the concerns of continued injection therapies by offering a variety of less invasive current and future choices.

Eye Drops

AMD patients may soon be able to administer normally injected drugs through painless eye drops instead. The University of Birmingham reports that Dr. Felicity de Cogan, from the University of Birmingham’s Institute of Microbiology and Infection, developed “cell-penetrating peptide (CPP) to deliver the drug to the relevant part of the eye within minutes”.

Dr. de Cogan commented,

“Efficacious self-administered drug application by eye drop would lead to a significant reduction in adverse outcomes and health care costs compared with current treatments. The CPP-plus drug complex also has potential application to other chronic ocular diseases that require drug delivery to the posterior chamber of the eye. We believe this is going to be very important in terms of empowering of patients and reducing the cost of treatment to the NHS [National Health Service].”

Biodegradable Microspheres

Development of neuroprotective therapies for macular degeneration has moved from a highly studied application to a real-time therapy treatment. This is because of the expansion of more user friendly drug delivery options like CPP. These options virtually eliminate pain and may enhance the possibility of accumulative drug management which can be otherwise more difficult when injections are administered.

MD magazine reported on a review paper that explored clinical issues when managing neurodegenerative optic diseases. It discussed how these issues could be bypassed by the use of biodegradable microspheres. These are “nano-holders” designed to easily carry low-molecular-weight, therapeutic medications without injections beyond restrictive obstacles such as corneal layers, sclera, retina, blood-aqueous and blood-retinal barriers. Injections were the only way to surpass these barriers which would otherwise restrict bioavailability of treatment drugs to targeted areas, require continued maintenance, and limit treatment routes. Now, biodegradable microspheres can make it into the eye and through these barriers by simply administering pain-free eyedrops.

The review paper of these microspheres was submitted by Irene Bravo-Osuna, PhD, with colleagues from the Department of Pharmacy and Pharmaceutical Technology at Complutense University in Madrid, Spain. It stated that this delivery enhancement would support “long-term sustained drug release” and “safe dosing of drugs with pharmacokinetics issues such as a rapid systemic clearance or a narrow therapeutic window”. 

Stem Cells

Another eye drop option to replace and surpass injectables is the ability for daily stem cell treatment for macular degeneration. Regenerative medicine is on the rise with stem cells being used to grow organs and replace diseased cells. When it comes to macular degeneration, many successful stem cell procedures have been performed through graft surgery and/or a protocol of injectable sessions. The process can be highly invasive and doesn’t always guarantee an effective outcome. Now, stem cell delivery may be able to be administered through eye drops.

According to Check Biotech, a company leading the way in this technology,

“Live cells offer a therapeutic strategy with the potential advantages of more effective client differentiation, immunomodulation [inducing, enhancing, or suppressing an immune response], antimicrobial properties and anti-apoptotic [cell death] effects.”

Beyond Macular Degeneration

With new delivery options for macular degeneration in the form of eye drops, many other eye diseases could be addressed through this application. Currently, eye drops to reverse cataracts have shown rising success in laboratory research from mice to dogs.

University of California San Francisco (UCSF) reported in 2015 that,

“A chemical that could potentially be used in eye drops to reverse cataracts, the leading cause of blindness, has been identified by a team of scientists from UC San Francisco (UCSF), the University of Michigan (U-M), and Washington University in St. Louis (WUSTL)…The team [] tested an eye-drop formulation in mice carrying mutations that make them predisposed to cataracts…[] they found that the drops partially restored transparency to mouse lenses affected by cataracts, as measured by a slit-lamp test of the sort used by ophthalmologists to measure cataracts in humans.”

These were preliminary tests that have since increased research to dogs. Dogs are prone to cataracts with half of breeds developing the disease by nine years of age and most developing cataracts later in life. The UCSF paper states that, “An effective eye-drop medication could potentially benefit about 70 million affected pet dogs in the United States.”

With dogs being the first to receive these treatments it won’t be long before they are applied to humans. In due time, cataract surgery may become a thing of the past as it is simply eradicated by prescription eye drop treatment.

New drug delivery options for macular degeneration therapy in the form of highly developed eye drops is a significant break through. Reducing or eliminating injection therapy brings hope to many. Those struggling not only with the physical and mental symptoms of eye disease would no longer have to be subjected to painful treatment as well. This change in delivery could enhance successful outcomes that may have been thwarted by the combined stress of eye disease and injectable management.