Scientists at Schepens Eye Research Institute have found that people with a certain low level of tear production are more likely to develop chronic dry eye syndrome after LASIK (laser-assisted in situ keratomileusis), laser refractive surgery to correct near- and far-sightedness than those with more plentiful tears. Their research, published in the January issue of Investigative Ophthalmology and Vision Science, may offer reliable prescreening criteria for ophthalmologists and patients.
“These findings should help ophthalmologists determine if pretreatment is necessary before surgery or if surgery is appropriate at all for an individual,” says Dr. Darlene Dartt, director of the Military Vision Research Program at Schepens Eye Research Institute and the principal investigator of the study.
Dry eye syndrome is one of the most common problems treated by eye physicians. Affecting more than 10 million Americans, it is caused by problems with the tear film responsible for lubricating the eye. While it does not cause vision loss, dry eye syndrome can be painful and severely decrease quality of life for its victims who constantly search for relief with artificial tears and other medications.
LASIK surgery uses small laser cuts to reshape the surface of the cornea, eliminating far-sightedness or near-sightedness, and the need for glasses or contacts. Many people choose LASIK for cosmetic reasons. In recent years, thousands of military personnel have opted for LASIK surgery because it can help them see better and identify objects and people in the field more quickly. It also relieves them of the worry about lost or damaged glasses.
Usually, LASIK causes some dry eye syndrome directly after surgery, but the condition resolves within a few months. In a small number of cases, however, the dry eye condition following LASIK can become chronic and impact functioning of both civilian and military individuals for as long as nine months following surgery.
Dartt and her team were determined to find a way to prescreen for the chronic condition so that surgeons could prepare patients in advance with preventative artificial tears or opt against surgery for some patients.
Dartt and her team evaluated the eyes of 24 patients about to undergo LASIK at the Massachusetts Eye and Ear Infirmary. The patients were given a series of evaluations, including the Schirmer test with and without anesthesia, before and after surgery. Using a piece of paper on the corneal surface, the Schirmer test measures the amount of tears an eye is producing. Study subjects also filled out a dry eye questionnaire indicating their experience with dry eyes pre- and post-operatively.
The team discovered that if a patient had a presurgical tear production value greater than 20 mm of wetting of the Schrimer strip in 5 minutes, they were not likely to develop chronic dry eye syndrome. Patients who produced less tears were more likely to develop long-term dry eye syndrome.
According to Dartt, the next steps for her team include expanding this study to a larger number of individuals and examining patients who have the PRK (photorefractive keratectomy) type of refractive surgery. The PRK has the same goal as LASIK, but the procedures differ. In LASIK a flap of corneal epithelium is cut and lifted to allow the underlying stroma to be shaped by the laser. Then the flap is placed down on the eye. In PRK the corneal epithelium is mechanically removed to allow laser shaping of the stroma. The epithelium then grows back over several days. LASIK and PRK have different side effects.
Patti Jacobs | EurekAlert!
New High-Performance Center Translational Medical Engineering
26.04.2017 | Fraunhofer ITEM
A promising target for kidney fibrosis
21.04.2017 | Brigham and Women's Hospital
More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.
Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...
Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.
"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...
The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.
Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...
The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...
Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.
Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...
20.04.2017 | Event News
18.04.2017 | Event News
03.04.2017 | Event News
26.04.2017 | Earth Sciences
26.04.2017 | Health and Medicine
25.04.2017 | Physics and Astronomy