Plastics have been pivotal in the development of contact lenses as Medical Plastics News editor Laura Hughes explains.
National Eye Health Week aims to help people know how to protect their sight, with a real focus on emphasising the point that, “your vision matters”.
The market for contact lenses is worth nearly US$15 billion, and around 125 million people around the world wear contact lenses. In order to make contact lenses, the companies supplying the machinery have to produce moulds. Additionally, every contact lens that is produced requires a bespoke mould, demonstrating the importance of good quality and expert manufacturing.
Previously the US Food and Drug Administration (FDA) approved Sensimed’s Triggerfish - a contact lens device for the treatment of optic nerve damage. The device works by being able to identify the optimal time of day to measure a patient’s IntraOcular Pressure (IOP). It is important to measure IOP as this is often linked to optic nerve damage, a characteristic of glaucoma. Without treatment, glaucoma can cause permanent blindness within a few years, but by measuring the IOP, glaucoma can be detected, treated and controlled. The mechanism of this lens works by having sensors which are embedded in a soft silicone contact lens which can be worn comfortably by the patient for up to 24 hours.
Research at Harvard Medical School (HMS) also produced interesting results. Joseph Ciolino, assistant professor of ophthalmology at HMS previously commented: “We found that a lower-dose contact lens delivered the same amount of pressure reduction as the latanoprost drops, and a higher-dose lens, interestingly enough, had better pressure reduction than the drops in our small study.” In this study the contact lens-based system used a strategically placed drug polymer film to deliver medication gradually to the eye, and claims to be as effective, and possibly more effective than daily latanoprost eye drops in a pre-clinical model for glaucoma. This research shows the benefits contact lenses could offer their users compared to drug administration. Contact lenses also overcome other issues commonly associated with eye drops such as patient compliance.
Recently, we have also seen the introduction of ‘smart’ contact lenses, and a smart contact lens was built to continuously measure glucose in tears using a wireless chip and miniaturised glucose sensor by the organisations, Google and Alcon. The smart lens technology involves non-invasive sensors, microchips and other miniaturised electronics, which are embedded within the contact lenses. Researchers hoped the smart contact lens would transform the lives of those with diabetes.
Of course, contact lenses can only demonstrate the benefits discussed above if they are correctly maintained, and the advice from the national eye health charity, Vision Matters is:
- Thoroughly wash and dry your hands before touching your contact lenses or your eyes
- Only ever use contact lens solution when cleaning the lenses
- Avoid wearing your contact lenses for longer than recommended
- Never shower, sleep or swim with your lenses in
I think contact lenses play an important role in ensuring people’s vision is maintained and/or improved, and with the world becoming increasingly digital, devices such as smart contact lenses will only become more common place.