Aston Biomaterials Research Unit (BRU) and Visioncare Research Ltd have joined forces via a CASE Award to research the discomfort faced by some users of extended wear contact lenses.
Silicone hydrogel lenses are increasingly popular due to their ability to be worn for extended periods of time or even overnight; this is possible because they allow more oxygen to the corneas than other lens materials. However, one disadvantage often cited by wearers, is a build-up on the lens of naturally occurring precipitates -known as lipids- due to their water resistant (hydrophobicity) properties. This, in time, can lead to dryness and discomfort that increases with wearing time. Patients who face this discomfort are cited as having “’ocular incompatibility’” and, as a result, often discontinue use of contact lenses. The current contact lens dropout rate is around 30% for first time wearers.
It is hoped that this collaboration will allow Visioncare to analyse patient’s responses to experimental or “’third generation’” silicone hydrogel lenses on an individual basis, as opposed to a generalised statistical assessment of patients with tear film abnormalities; which includes dry uncomfortable eyes. This is of increasing importance due to environmental factors such as heavy use of central heating and air conditioning.
Graeme Young of Visioncare Research noted “We are very happy to be working with Aston Biomaterial Group who are acknowledged to be world leaders in this field”.
As yet, there is no current biochemical diagnostic to explain the condition. By researching this phenomenon Visioncare will be able to provide useful insight to manufacturers undertaking work in this field, thus allowing them to compete more competitively with their US counterparts. It is hoped the social and economic benefits to the wider field of ophthalmic biomaterials from this research could also stretch into areas such as artificial corneas, which can be transplanted to help restore patients’ sight.
Dr Val Franklin of Aston’s Biomaterials Research Unit commented on the related benefits of the project, “The materials used for artificial corneas face the same issues as those of contact lenses in terms of biocompatibility, so any techniques for assessing such interaction using contact lenses could be applied to the artificial cornea and aid development and long term success of such implants”.