Optical fibers for laser welding of corneal transplants
Already about 30,000 years ago, prehistoric humans learned to use animal bones as needles to sew up potentially fatal wounds. Perfected by time, this practice still remains the basis of most modern surgical interventions. However, even such innovative approaches to wound suturing as the use of metal and polymer staples or chemical adhesives do not exclude infection of sutures and the formation of lifelong scars.
Professor Abraham Kazir from Tel Aviv University has devoted most of his career to honing the technology he developed, known as "laser welding". This technology consists in heating the edges of the wound controlled with high precision, ensuring its optimal fixation. A fundamentally new direction of application of this method, developed by the Katzira group, is its use to strengthen corneal grafts in the tissues of the eye.
Corneal transplantation, or keratoplasty, restores vision to patients suffering from diseases such as corneal bloating, Fuchs dystrophy, corneal thinning, corneal scars caused by infections and injuries, cataracts, corneal swelling, corneal ulcers or complications of earlier surgical interventions. This painful procedure requires months of recovery with a pronounced pain syndrome caused by stitches remaining in the tissues of the eye.
According to Professor Katsir, for the application of internal sutures and the connection of tiny vessels of the eye, the surgeon must be a master of his craft. Therefore, the medical community is very interested in methods that can facilitate the procedure and make such operations accessible to surgeons who do not have many years of experience in suturing.
To solve this problem, the authors have developed unique optical fibers made of silver halides. These fibers, transparent to the infrared part of the spectrum, conduct infrared light, gently heating the edges of the incision. At the same time, the same fiber delivers infrared radiation from sequentially heated areas to a detector acting as a thermometer. This ensures that each section is heated to the desired temperature (60-65 degrees Celsius), which is necessary for strong stitching of the edges of the incision with minimal temperature damage to the fabric.
The new approach has been successfully tested on the eyes of dead cows and pigs. Based on the results of this testing, Professor Katsir received permission to conduct experiments on live animal models. In parallel, he applies his technology during endoscopic interventions.
As part of a recent clinical trial, ten volunteers had incisions made on their skin, which were subsequently treated with a new fiber-optic technology. As a result, the incisions were successfully tightened almost without the formation of scar tissue. Professor Katsir believes that the possibilities of using his development are almost limitless. It can be used in plastic surgery, urology, otolaryngology, brain surgery, emergency medicine, as well as for suturing wounds resulting from trauma.
Article by Porat et al. Optical coherence tomography (OCT) in laser tissue bonding of incisions in the cornea is published in the Journal of Biomedical Optics.
Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of American Friends of Tel Aviv University:
Eyes Sealed Shut: Seamless Closure of Surgical Incisions.
04.06.2015