Glaucoma under the lens

Contact lenses that slowly deliver the glaucoma medication latanoprost have been found to be able to control intraocular pressure (IOP) more effectively than eye drops.

The new continuous-wear contact lenses were trialled in monkeys with the sight loss-causing condition, in a paper published in the journal Ophthalmology.

Researcher and Harvard Medical School assistant professor, Dr Joseph Ciolino, explained that the low-dose, latanoprost-releasing contact lenses were as good as drops at lowering IOP. Meanwhile, the high-dose lenses showed a higher IOP reduction than both, in the research funded by the Boston Children’s Hospital.

Until now, many contact lenses that are designed to deliver medications release the drugs too quickly. However, the researchers used a thin film of long-chained molecules, encapsulating the drugs, on the periphery of the contact lens.

This concept enables the contact lens to very slowly deliver latanoprost, but also remain transparent and breathable. It also means that the contact lenses can have zero power or be tailored to a patient’s prescription.

This contact lens technology could be the solution to the low adherence rates for patients using eye drops, which are known to sting and can also be difficult to self-administer, Dr Ciolino highlighted.

He said that the contact lens is capable of releasing the medication for a month, and emphasised that: “Based on our preliminary data, the contact lenses have not only the potential to improve compliance for patients, but also the potential of providing better pressure reduction than the drops.”

The researchers are now designing clinical trials to test the lenses on patients, Dr Ciolino outlined, adding: “If we can address the problem of compliance, we may help patients adhere to the therapy necessary to maintain vision in diseases like glaucoma, saving millions from preventable blindness.”

Image credit: John Earle Photography