(Press-News.org) More than 20 years after the launch of a landmark clinical trial, follow-up examinations and analyses found that not all patients with elevated eye pressure need pressure-lowering treatment to prevent vision loss from glaucoma.
When the study was launched, it was universally accepted that all patients with elevated eye pressure should be given medication to lower that pressure. The Ocular Hypertension Treatment Study -- funded by the National Eye Institute of the National Institutes of Health (NIH) and led by researchers at Washington University School of Medicine in St. Louis -- recruited more than 1,600 patients nationally who were at moderate to high risk for glaucoma because of elevated eye pressure. The purpose was to evaluate how successful medication was at preserving vision.
Half of the patients were randomly selected to receive daily treatment with eye drops to lower intraocular pressure, and the other half were observed without treatment. After seven years, when the treatment had been shown to be highly effective, patients in both groups were given the treatment. In this latest phase of the study, researchers evaluated which patients went on to develop glaucoma after the initial study had concluded.
As reported online April 15 in the journal JAMA Ophthalmology, the researchers found that about 25% of study participants went on to develop vision loss from glaucoma in at least one eye, a lower rate than what was expected. The conventional thinking had been that most patients with elevated eye pressure probably should receive treatment.
"But treating elevated eye pressure can be expensive and inconvenient, so we wanted to determine whether all individuals with high pressure should be treated," said Michael A. Kass, MD, the Bernard Becker Professor of Ophthalmology & Visual Sciences. "With only 25% of the individuals in the study developing vision loss in one or both eyes after all these years, we know now that not all of those patients needed to be treated."
Glaucoma is one of the leading causes of blindness in the United States and the No. 1 cause of blindness in Black Americans. Elevated eye pressure develops in 4% to 7% of the people in the United States over age 40, and the conventional wisdom prior to the study had been to prescribe pressure-lowering drops. But those medications can cost hundreds of dollars per year; they can cause side effects in some people; and many people, especially older individuals, find it difficult to put drops in their eyes every day.
Fluid in the eye regularly flows in and out. Elevated pressure results when the fluid drains too slowly.
In the initial phase of the study, the incidence of glaucoma fell significantly in those who received treatment.
"We showed that preventive treatment clearly works because it reduced the incidence of glaucoma by 50% to 60% after five to seven years," said Kass, who served as national chair of the study. "But even with that substantial decrease, the total number of people who developed glaucoma remained relatively low. We had shown that treatment is effective, and we demonstrated that not everyone with high eye pressure needs to be treated."
The follow-up analysis sought to uncover patterns and risk factors to identify which patients needed pressure-lowering treatment and which might simply require monitoring. Of the study participants, 46% had evidence of glaucoma in one or both of their eyes, but only 25% had experienced any vision loss when examined 20 years after the study's launch.
"One of the strengths of our study was that about one-quarter of the patients we followed were Black, a group with a higher incidence of visual loss from glaucoma," said Mae O. Gordon, PhD, a professor in the John F. Hardesty, MD, Department of Ophthalmology & Visual Sciences and in the Division of Biostatistics, who led the data analysis for the national study. "We found that over the course of the study, more than half of the African American patients did develop signs of disease. However, Black individuals had similar outcomes to people from other groups when they were matched for the same levels of risk."
Early in the study, the researchers identified five factors that predicted which patients were at higher risk for developing glaucoma. These factors -- confirmed by the follow-up analysis -- were useful in deciding how often patients need to be examined and whether they might benefit from preventive treatment.
These factors are a patient's age; level of intraocular pressure; thickness of the cornea; a measurement of the appearance of the optic nerve head; and another measurement derived from standard visual field tests.
Kass said when those factors are quantified, it's clear many patients with elevated pressure can be managed by regular monitoring and may not require treatment. He said the long-term study demonstrates that patients and their doctors can work together to decide whether and how to begin treatment to lower eye pressure and that finding the best course for treating people with high intraocular pressure is not a one-size-fits-all proposition.
"Elevated pressure in the eye should start a conversation between doctors and patients to determine the best approach," Kass said.
The study also showed that the risks associated with delaying the start of drug treatment are relatively low. People randomly assigned to observation in the early phase of the study, before switching to pressure-lowering drops later on, had only a slightly higher risk of vision loss after 20 years than those who used pressure-lowering eye drops from the start of the study.
"We can delay pressure-lowering treatment until early damage is detected, and it doesn't seem to adversely affect long-term outcomes," Kass said.
Kass, MA, et al for the Ocular Hypertension Study Group. Assessment of cumulative incidence and severity of primary open-angle glaucoma among participants in the Ocular Hypertension Treatment Study after 20 years of follow-up. JAMA Ophthalmology, published online April 15, 2021.
INFORMATION:
This work was supported by the National Eye Institute and the Institute of Clinical and Translational Sciences of the National Institutes of Health (NIH). Grant numbers UL1 TR002345, U10 EY09341, U10 EY09370, UG1 EY025180, UG1 EY025181, UG1 EY025182, UG1 EY25183, and P30 EY002687. Additional support from Research to Prevent Blindness.
Washington University School of Medicine's 1,500 faculty physicians also are the medical staff of Barnes-Jewish and St. Louis Children's hospitals. The School of Medicine is a leader in medical research, teaching and patient care, consistently ranking among the top medical schools in the nation by U.S. News & World Report. Through its affiliations with Barnes-Jewish and St. Louis Children's hospitals, the School of Medicine is linked to BJC HealthCare.
Prime editing (PE), a "search-and-replace" CRISPR-based genome editing technique, has great potential for gene therapy and agriculture. It can introduce desired base conversions, deletions, insertions, and combination edits into target genomic sites. Prime editors have been successfully applied in animals and plants, but their off-target effects, which can be a major hindrance to real-life application, have not been thoroughly evaluated until now.
Prof. GAO Caixia from the Institute of Genetics and Developmental Biology (IGDB) of the Chinese Academy of Sciences (CAS) and her research team recently performed a comprehensive and genome-wide analysis of the off-target effects of PEs in rice plants.
Off-target ...
It is an old-standing theory in evolutionary ecology: animal species on islands have the tendency to become either giants or dwarfs in comparison to mainland relatives. Since its formulation in the 1960s, however, the 'island rule' has been severely debated by scientists. In a new publication in Nature Ecology and Evolution on April 15, researchers solved this debate by analysing thousands of vertebrate species. They show that the island rule effects are widespread in mammals, birds and reptiles, but less evident in amphibians.
Dwarf hippos and elephants in the Mediterranean islands are examples of large ...
Using a new single-cell technique, WEHI researchers have uncovered a way to understand the programming behind how stem cells make particular cell types.
The research uncovered 30 new genes that program stem cells to make the dendritic cells that kick-start the immune response.
By uncovering this process, the researchers hope they will be able to find new immunotherapy treatments for cancer, and plan to expand this technique in other areas such as discovering new drug targets in tumour initiation.
At a glance
WEHI researchers have developed a new single cell method to understand the programming behind what causes stem cells to make ...
El Niño-Southern Oscillation (ENSO) is an irregular periodic variation in winds and sea surface temperatures (SSTs) over the tropical eastern Pacific Ocean. It may lead to extreme weather events across the globe due to its ability to change global atmospheric circulation. Thus, determining how ENSO responds to greenhouse warming is crucial in climate science.
However, quantifying and understanding ENSO-related changes in a warmer climate remains challenging due to the complexity of air-sea feedbacks in the tropical Pacific Ocean and to model bias.
An international team of scientists ...
Antibodies are not only produced by our immune cells to fight viruses and other pathogens in the body. For a few decades now, medicine has also been using antibodies produced by biotechnology as drugs. This is because antibodies are extremely good at binding specifically to molecular structures according to the lock-and-key principle. Their use ranges from oncology to the treatment of autoimmune diseases and neurodegenerative conditions.
However, developing such antibody drugs is anything but simple. The basic requirement is for an antibody to bind to its target molecule in an optimal way. At the same time, an antibody drug must fulfil a host of additional criteria. For example, it should not trigger ...
COVID-19 has been associated with increases in opioid overdose deaths, which may be in part because the pandemic limited access to buprenorphine, a treatment used for opioid dependency, according to a new study led by Princeton University researchers.
The researchers found that Americans who were already taking opioids did not experience disruptions in their supply. Patients who were not previously taking opioids for pain management were less likely to receive a new prescription in the first months of the pandemic, but prescriptions for new patients soon bounced back to previous levels.
At the same time, fewer ...
A number of SARS-CoV-2 variants have emerged from immunocompromised hosts, research has identified. It is thought that variants of concern - including B.1.1.7, a variant first identified in Kent - were a result of long-term infection in people with a weakened immune system.
Persistent infections in immunocompromised people could cause the virus to mutate more frequently because the person's immune system cannot clear the virus as quickly as the immune system of a healthy person.
Authors Professor Wendy Barclay, Dr Thomas Peacock, Professor Julian Hiscox and Rebekah Penrice-Randal explain the importance of monitoring genetic changes in SARS-CoV-2 for future control of the virus: ...
Besides enabling more potent smartphones and higher download speeds while riding the subway, cutting-edge technologies like artificial intelligence, robotics, and wireless communications are on the verge of revolutionizing well-established industrial fields. A remarkable example is "smart agriculture," which has seen a tremendous increase in the use of drones for various tasks, especially in Japan.
Drones, or "unmanned aerial vehicles" (UAVs), have been the focus of extensive research for agricultural applications. For example, they can take aerial images of a field and, through subsequent image processing, identify problems in specific areas of the crop fields. Another notable use case for UAVs that has been quickly gaining traction is the spraying of pesticides. In ...
The extreme summer drought of 2018 was a special situation for both nature and scientists. It was very hard on the forest. At the same time, it offered researchers from the Universities of Basel (Switzerland) and Würzburg (Germany) the opportunity to study the reaction of trees to this climatic phenomenon.
Research in the treetops
"The summer of 2018 was hotter and drier than in any other year since weather records began," says ecophysiologist Professor Bernhard Schuldt from the University of Wuerzburg. Together with Dr Matthias Arend and Professor Ansgar Kahmen from the University of Basel, he was significantly involved in the study, which is published in the scientific journal PNAS. "A unique opportunity arose for us to study the influence of ...
A new paper in the Review of Economic Studies indicates that disease can alter the social networks and economic growth of countries for generations, even after the disease itself is eradicated.
Social networks are an important determinant of a country's growth as they affect the diffusion of ideas and the rate of technological progress. But social networks also diffuse diseases that can rapidly spread and dampen growth.
As ideas and germs diffuse through the same human interactions, the network structure of a country ultimately depends on its epidemiological environment. In countries with low prevalence of infectious diseases, high diffusion networks ...
