Microscopic needles effectively deliver drugs to the eyes

Jun 30 2008

A new technique that effectively delivers drugs to the eyes, using microscopic needles, could offer hope to the millions of patients worldwide suffering from common eye diseases that threaten vision such as glaucoma, macular degeneration and diabetic retinopathy.

Researchers at the Georgia Institute of Technology and Emory University in America will present this research, entitled "Microneedles for Ocular Drug Delivery," to international experts at the Ophthalmic Drug Delivery symposium being held at the Royal Pharmaceutical Society of Great Britain today.

The research looks at how microneedles can be used to deliver drugs to the eye through a minimally invasive procedure. The needles used to penetrate the eye only go as deep as half a millimetre into the eye tissue. This means that the needles do not penetrate far enough to cause as much damage as traditional needles. As a result, they can be applied to the eye using only local anaesthetic.

This technique has the potential to revolutionise the way of treating common eye conditions such as glaucoma, macular degeneration and diabetic retinopathy. Traditional delivery methods such as eye drops have difficulty in efficiently delivering drugs to the back of the eye, and ordinary injections are invasive as the needle penetrates across eye tissues. Repeated injections with regular needles can also result in other serious complications to vision.

Samirkumar Patel from the research team, said: "The eyes are one of the most sensitive and delicate organs in the human body, and perhaps the most fascinating. They present us with the window through which we view the world, and are responsible for four fifths of all the information our brain receives.

"Although the research is at an early stage it does show that it is possible to use microneedles to effectively deliver drugs to targeted sections of the eye, such as the anterior and posterior portions. No inflammatory response or other adverse effects were observed in our early tests. This is promising news for those who are suffering from vision threatening diseases such as glaucoma, macular degeneration and diabetic retinopathy."

The next stage of development will be further research to confirm safety and gain a better understanding of the long-term effects.

Notes:

Glaucoma

Glaucoma is the name of a group of eye diseases that affect vision. If left untreated glaucoma can eventually cause blindness. Glaucoma is more common in old age, and happens when the optic nerve in the eye is damaged. Open angle glaucoma affects about two in every hundred people over the age of 40. However, this increases over the age of 70 to one person in ten.

(Source: NHS Direct)

Macular degeneration

Macular degeneration is a painless disorder that affects the macula, the central part of the retina in the eyes, causing progressive loss of central and detailed vision. Macular degeneration is the most common reason for people in the UK to be registered blind, though total blindness almost never occurs from this condition. Age-Related Macular Degeneration is the most common form of macular degeneration although there are some rare forms that affect younger people. The incidence increases with each decade over the age of 50 to almost 15% by the age of 75. Macular degeneration is more common in females. Other risk factors include family history, and smoking.

(Source: NHS Direct)

Diabetic retinopathy

Diabetic retinopathy is one of the most common causes of blindness in the UK in people between the ages of 30-65, and 12% of people who are registered blind and partially sighted each year have diabetic eye disease. Retinopathy means damage to the tiny blood vessels (capillaries) that nourish the retina, the tissues in the back of the eye that deal with light. Damage to these vessels causes blood leakage (haemorrhage), which may be small and confined to the retina, or may extend forward into the jelly that fills the main cavity of the eye (the vitreous gel). This can seriously affect the vision.

(Sources: NHS Direct and Henshaws Society for Blind People)

About the Royal Pharmaceutical Society of Great Britain

The Royal Pharmaceutical Society of Great Britain is the professional and regulatory body for pharmacists in England, Scotland and Wales. It also regulates pharmacy technicians on a voluntary basis, which is expected to become statutory under anticipated legislation. The primary objectives of the Society are to lead, regulate, develop and represent the profession of pharmacy. The Society leads and supports the development of the profession within the context of the public benefit. This includes the advancement of science, practice, education and knowledge in pharmacy. In addition, it promotes the profession's policies and views to a range of external stakeholders in a number of different forums. Following the publication in 2007 of the Government White Paper Trust, Assurance and Safety - The Regulation of Health Professionals in the 21st Century, the Society is working towards the demerger of its regulatory and professional roles. This will see the establishment of a new General Pharmaceutical Council and a new professional body for pharmacy in 2010.