Because slow and steady delivery of medicines to the eye is beneficial in the treatment of various ocular diseases, scientists have been studying ways of modifying contact lenses so that they could perform this function effectively. Here, numerous factors, such as the properties of the lens surface, water content or thickness, have to be taken into account, which makes the issue a complex one.

Researchers have already come up with different forms of drug-dispensing contact lenses, which use different approaches to the problem. One of them is to put liposomes containing medications on the surface of the contact lens and disperse them in the matrix of the lens, achieving release time of up to seven days. Another is to use a PLGA polymer film, which can store large quantities of medications and release them slowly for as long as 30 days, or vitamin E, which increases the release time of certain drugs of up to 100 times.

These experimental methods (and several others) show a lot of promise, though they must be significantly modified before a clinically reliable contact lens drug delivery system becomes a viable option for eye care practitioners.

Marietta Vision has announced the launch of the new Bio contact lens. The company claims that the new contact lenses are more natural than others because it is produced with a biocompatible contact lens material, Hioxifilcon/GMA.

The biocompatibility of the new lens is attained through the synthesis of the characteristics of mucin, which is a natural wetting substance of the human body. In consequence, the lens binds water, which protects it from dehydration and increases the wettability of its surface. Because of that, the user may enjoy enhanced comfort and longer wearing times.

As far as optics are concerned, the Bio lens utilises aspheric technology, which corrects aberration and masks low levels of astigmatism, so many patients will not need to purchase special astigmatism-correcting lenses.

President of Marietta Vision, John M. Patterson, stated that Bio lenses give contact lens wearers a green alternative, which is extremely important for a number of consumers. Environmentally conscious customers will also appreciate the fact that even the packaging of the lenses is biodegradable.

A next generation silicone hydrogel hybrid contact lenses manufactured by SynergEyes has received the approval of the US Food and Drug Administration. The company is going to market the lens as Duette (for astigmatism) and Duette Multifocal (for presbyopia).

The new lenses are approved for the correction of myopia, hyperopia and astigmatism, and are made with a new GP material developed by SynergEyes, called MaxVu, characterised by high gas permeability and include a Flex2O silicone hydrogel skirt. Moreover, the lenses are manufactured with the use of a new, patent-pending surface treatment technology, increasing wettability and preventing protein deposits. They are indicated for daily wear and their correction range is -20.00D to +20.00D in eyes with astigmatism no greater than +6.00D.

At the moment, Duette lenses are available in selected practices in the US (a mass-scale launch is planned for 2011), while Duette Multifocal should be introduced at the beginning of 2011 (in a limited release).

Studies conducted among the UK contact lens wearers suggest that approximately one quarter of all the people who decide to start to wear contact lenses do it because they want to practise sports. In addition, many contact lens wearers start doing sports simply because, thanks to their lenses, they can.

Wearing contact lenses instead of glasses while practising sports has numerous advantages. Dr Christine Purslow, in her article published in Optometry Today, lists the most important ones, including wide field of view, no vision problems in the rain, possibility to wear sports glasses or goggles, image size closer to the actual object size, no reflections or misting, little likelihood of breakage or loss.

Because of their qualities, daily contact lenses are a favourite among contact lens wearers who are involved in sporting activities. In comparison with rigid contact lenses, they decrease the chance of a potential eye injury, so they are essential in contact sports. Moreover, if lost, they can be immediately replaced with a fresh pair at a low cost.

The latest reports concerning the contact lens market inform that Abbot, the manufacturer of numerous medical products, has recalled its contact lenses solutions. The reason for the recall, provided by the Wall Street Journal, was that some of the bottles had loose-fitting caps, which might have an impact on the lifespan and sterility of the solutions, which could put Abbot customers in danger of infections and other severe complications.

The company issued a statement that, so far, the problem has not caused any adverse effects, diseases or injuries. The recalled products are Complete Multi-Purpose Solution and Total Care (1) Contact Lens Solution; the Medicines and Healthcare Products Regulatory Agency’s Friday alert confirmed the recall and warned customers not to use the affected lot of the solutions in question, though it also stated that the problem concerned not the solutions themselves, but their faulty flip-top caps, causing leaks.

Abbot Laboratories entered the contact lens solutions market last year, when the company bought Advanced Medical Optics. It has been working on a new solution, called RevitaLens, awaiting approval of the FDA and already approved in Europe.