I Can See Clearly Now

Patients could recover from cataract surgery a lot quicker thanks to the development of a new, adhesive hydrogel that can be painted over incisions in the eye and so avoid conventional nylon sutures. The liquid hydrogel, based on a dendritic macromer, has optical properties similar to the cornea, the layer that covers the iris and pupil of the eye. The use of this hydrogel may preclude complications associated with sutures or unsutured incisions that are left to heal on their own.


Mark Grinstaff

Cataracts are characterized by a clouding of the lens of the eye. Surgery to remove an affected lens and replace it with an artificial lens to improve vision is one of the most commonly performed surgical procedures in the West, with more than 1.5 million procedures performed each year in the USA alone, according to the US National Eye Institute. As the population gets older, the number of procedures carried out is expected to rise.

Many cataract patients are reluctant to have their eyes sutured, but often this has been the best approach to healing. Now, Mark Grinstaff of Boston University Departments of Biomedical Engineering and Chemistry and his colleagues, and Terry Kim of Duke University Medical Center in Durham, North Carolina, have developed an alternative to sutures based on a transparent glue-like polymer similar to the materials used in "liquid bandages".

"Sutures can be difficult to care for and are hard on the eyes," says biomedical engineer and chemist Grinstaff. "Our hydrogel adhesive could ultimately replace the use of sutures for eye surgery altogether and go a long way toward improving patient care."

The team prepared the material from a peptide dendron possessing terminal cysteine residues, which they mixed with poly(ethylene glycol dialdehyde) in aqueous solution at pH 7.4 to produce a spontaneous hydrogel as thiazolidine linkages between the macromers formed.

The hydrogel adhesive might also find use as an alternative to sutures in reparative surgery on ulcers, corneal and retinal injuries, and other problems including post-procedure repairs following LASIK eye surgery. The hydrogel is yet to go through full testing, but Grinstaff and Kim believe it could be available to physicians in three to four years.