What type of lens is best after cataract surgery – multifocal or monofocal? It depends, study says
Multifocal intraocular lenses improve near vision without compromising distance vision. However, patients with these intraocular lenses may experience reduced contrast sensitivity and they may see haloes around lights. These are the conclusions of a study appearing in the September issue of Ophthalmology, the clinical journal of the American Academy of Ophthalmology, the Eye M.D. Association.
Monofocal lenses are the current standard of treatment, but usually require spectacles for near vision. The choice between the two types of lenses depends on patients motivation to be free of glasses and contact lenses and on their having realistic expectations about the outcomes and compromises involved.
In this systematic literature review and meta-analysis of eight randomized controlled trials, the researchers examined a number of different outcomes: distance and near visual acuity, both unaided and corrected; spectacle independence; depth of field; contrast sensitivity; glare; subjective assessment of quality of life or visual function; and surgical complications.
Though there was significant variability in outcomes among the trials, in general it was found that distance acuity was similar in multifocal and monofocal intraocular lenses, and that unaided near vision tended to improve with the multifocal lens. Independence from spectacles was found in 26 percent to 47 percent of patients with multifocal lenses, but only in 1 percent to 11 percent of those with monofocal lenses. In addition, multifocal lenses increased depth of field. However, the multifocal lens also reduced contrast sensitivity and resulted in the subjective experience of seeing haloes around lights.
"This study is a very realistic interpretation of the multifocal versus monofocal tradeoff," said Academy spokesperson Samuel Masket, MD, clinical professor of ophthalmology at the Jules Stein Eye Institute, UCLA School of Medicine. "The key to choosing multifocal lenses is strong motivation on the part of the patient to be free of glasses and contact lenses. The patient must consciously accept a reduction in the quality of vision in order to have just under a 50-50 chance of being spectacle free."
Dr. Masket said because of the information and advertising about refractive surgery outcomes, many patients have high expectations. "They often anticipate that lens replacement surgery is equivalent to refractive surgery. In fact, as the study indicates, current multifocal lenses may or may not match those expectations. He added that truly accommodating intraocular lenses, which move back and forth inside the lens capsule so the eye can focus both near and far, are currently under development and will probably replace the existing types of lenses in four to six years.
The American Academy of Ophthalmology is the worlds largest association of eye physicians and surgeons – Eye M.D.s – with more than 27,000 members worldwide. For more information about eye health care, visit the Academys partner Web site, the Medem Network at www.medem.com/eyemd. To find an Eye M.D. in your area, visit the Academys Web site at www.aao.org.
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
Germany counts high-precision manufacturing processes among its advantages as a location. It’s not just the aerospace and automotive industries that require almost waste-free, high-precision manufacturing to provide an efficient way of testing the shape and orientation tolerances of products. Since current inline measurement technology not yet provides the required accuracy, the Fraunhofer Institute for Laser Technology ILT is collaborating with four renowned industry partners in the INSPIRE project to develop inline sensors with a new accuracy class. Funded by the German Federal Ministry of Education and Research (BMBF), the project is scheduled to run until the end of 2019.
New Manufacturing Technologies for New Products