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!
Inselspital: Fewer CT scans needed after cerebral bleeding
20.03.2019 | Universitätsspital Bern
Building blocks for new medications: the University of Graz is seeking a technology partner
19.03.2019 | Karl-Franzens-Universität Graz
Nano- and microtechnology are promising candidates not only for medical applications such as drug delivery but also for the creation of little robots or flexible integrated sensors. Scientists from the Max Planck Institute for Polymer Research (MPI-P) have created magnetic microparticles, with a newly developed method, that could pave the way for building micro-motors or guiding drugs in the human body to a target, like a tumor. The preparation of such structures as well as their remote-control can be regulated using magnetic fields and therefore can find application in an array of domains.
The magnetic properties of a material control how this material responds to the presence of a magnetic field. Iron oxide is the main component of rust but also...
Due to the special arrangement of its molecules, a new coating made of corn starch is able to repair small scratches by itself through heat: The cross-linking via ring-shaped molecules makes the material mobile, so that it compensates for the scratches and these disappear again.
Superficial micro-scratches on the car body or on other high-gloss surfaces are harmless, but annoying. Especially in the luxury segment such surfaces are...
The Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT) in Arizona released its first image of the surface magnetic field of another star. In a paper in the European journal Astronomy & Astrophysics, the PEPSI team presents a Zeeman- Doppler-Image of the surface of the magnetically active star II Pegasi.
A special technique allows astronomers to resolve the surfaces of faraway stars. Those are otherwise only seen as point sources, even in the largest telescopes...
Researchers at Chalmers University of Technology and the University of Gothenburg, Sweden, have proposed a way to create a completely new source of radiation. Ultra-intense light pulses consist of the motion of a single wave and can be described as a tsunami of light. The strong wave can be used to study interactions between matter and light in a unique way. Their research is now published in the scientific journal Physical Review Letters.
"This source of radiation lets us look at reality through a new angle - it is like twisting a mirror and discovering something completely different," says...
New research group at the University of Jena combines theory and experiment to demonstrate for the first time certain physical processes in a quantum vacuum
For most people, a vacuum is an empty space. Quantum physics, on the other hand, assumes that even in this lowest-energy state, particles and antiparticles...
11.03.2019 | Event News
01.03.2019 | Event News
28.02.2019 | Event News
21.03.2019 | Life Sciences
21.03.2019 | Physics and Astronomy
21.03.2019 | HANNOVER MESSE