Coated lenses set to reduce 'post-op' infections for cataract patients

Sep 7 2008

Research presented at the British Pharmaceutical Conference (BPC) in Manchester reveals that coating an artificial lens with antibiotics could significantly reduce the risk of post-operative infection, and even blindness, for cataract patients.

Cataract surgery is one of the most common operations in adults, with 250,000-300,000 procedures carried out each year in the UK.(1) The surgery involves removing the eye's natural lens that has become cloudy and replacing it with an artificial lens known as an intraocular lens (IOL). Infectious endophthalmitis is a rare but serious inflammation of the tissues inside the eye that can lead to blindness. It is often caused by bacteria entering the eye during cataract surgery and binding to the IOL.

Great efforts have been made to reduce the risk of endophthalmitis, for example, using eyedrops prior to surgery; injecting antibiotics into the eye after surgery, and improving the method of cataract surgery and the materials from which the IOLs are manufactured.

Researchers at the School of Pharmacy, Queen's University Belfast, are excited by a new type of hydrogel that can hold the antibiotic, gentamicin. They hope to coat the IOLs with this hydrogel, loaded with the antibiotic, to protect the eye against infection during and immediately after surgery. The idea is that once the artificial lens is in place, the antibiotics will be gradually released from the coating, killing bacteria within the eye and preventing them from sticking to the IOL surface.

The research team found that the hydrogel successfully held the antibiotic and then released it in quantities that theoretically would kill the offending bacteria. In a follow-up study, using bacteria grown in the laboratory, they also proved that the antibiotic-loaded hydrogel was effective at killing bacteria commonly responsible for endophthalmitis.

Researcher Dr Carole Parsons said: "Incorporating gentamicin into the hydrogels significantly reduced bacteria sticking to the IOL surface, indicating that these antibiotic-impregnated hydrogels would be highly beneficial as IOL coatings."

The next stage will be to perform pre-clinical and clinical testing, now that this laboratory-based research has proven the concept works.