More than 20 years after the launch of a landmark clinical trial, follow-up examinations and analyzes have found that not all patients with high eye pressure need anti-pressure therapy to prevent vision loss due to glaucoma.
When the study was started, it was universally agreed that all patients with high eye pressure should be given drugs to lower this pressure. The ocular hypertension treatment study – funded by the National Eye Institute of the National Institutes of Health (NIH) and led by researchers at the Washington University School of Medicine in St. Louis – recruited more than 1,600 patients to the nationwide including the risk of glaucoma due to high eye pressure. The aim was to assess how successful the drugs were in 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 was found to be highly effective, patients in both groups received the treatment. In this final phase of the study, the researchers evaluated patients who developed glaucoma after the initial study ended.
As reported online April 15 in the newspaper JAMA Ophthalmology, the researchers found that about 25% of study participants developed vision loss due to glaucoma in at least one eye, a rate lower than expected. The conventional thinking was that most patients with high eye pressure should probably receive treatment.
“But treating high eye pressure can be expensive and inconvenient, so we wanted to determine if all people with hypertension should be treated,” said Michael A. Kass, MD, Bernard Becker Professor of Ophthalmology and of visual sciences. “With only 25% of the people in the study developing vision loss in one or both eyes after all these years, we now know that not all of these patients needed treatment.”
Glaucoma is one of the leading causes of blindness in the United States and the leading cause of blindness among black Americans. High eye pressure develops in 4% to 7% of people in the United States over 40, and the conventional wisdom before the study was to prescribe pressure-lowering drops. But these drugs can cost hundreds of dollars a year; they can cause side effects in some people; and many people, especially the elderly, find it difficult to get drops in their eyes on a daily basis.
Fluid in the eye comes in and goes out regularly. High pressure occurs when fluid flows too slowly.
In the initial phase of the study, the incidence of glaucoma dropped significantly in those who received treatment.
“We have shown that preventative treatment clearly works because it reduces 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 this substantial decrease, the total number of people who developed glaucoma remained relatively small. We have shown treatment to be effective, and we have shown that not all people with ocular hypertension need treatment. ‘to be processed. “
The follow-up analysis sought to uncover patterns and risk factors to identify which patients needed anti-pressure therapy and which might simply need monitoring. Of the study participants, 46% had signs of glaucoma in one or both eyes, but only 25% had experienced vision loss on the exam 20 years after the study started.
“One of the strengths of our study was that about a quarter of the patients we followed were blacks, a group with a higher incidence of visual loss from glaucoma,” said Mae O. Gordon, PhD, professor. to John F. Hardesty, MD, Department of Ophthalmology and Visual Sciences and the Division of Biostatistics, who led the data analysis for the national study. “We found that during the study, more than half of African American patients developed signs of illness. However, black individuals had similar results to other groups when paired. for the same levels of risk. “
At the start of the study, the researchers identified five factors that predicted which patients were at higher risk of developing glaucoma. These factors – confirmed by the follow-up analysis – were helpful in deciding how often patients should be seen and whether they can benefit from preventive treatment.
These factors are the age of the patient; intraocular pressure level; thickness of the cornea; a measure of the appearance of the optic nerve head; and another measurement derived from standard visual field tests.
Kass said that when these factors are quantified, it is clear that many patients with elevated pressure can be managed with regular monitoring and may not require treatment. He said the long-term study demonstrates that patients and their doctors can work together to decide if and how to start treatment to reduce eye pressure and that finding the best treatment to treat people with high intraocular pressure does. is not a one-size-fits-all solution. any proposal.
“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 therapy are relatively low. People randomly assigned to observation at the start of the study, before later switching to antihypertensive drops, had only a slightly higher risk of vision loss after 20 years than those who used eye drops. antihypertensive drugs since the start of the study. .
“We can delay pressure lowering therapy until early damage is detected, and it doesn’t appear to affect long-term results,” Kass said.
Kass, MA, et al for the Ocular Hypertension Study Group. Assessment of the cumulative incidence and severity of primary open-angle glaucoma in participants in the ocular hypertension treatment study after 20 years of follow-up. Ophthalmology JAMA, published online 15 April 2021.
This work was supported by the National Eye Institute and the Institute of Clinical and Translational Sciences at the National Institutes of Health (NIH). Tune in UL1 numbers TR002345, U10 EY09341, U10 EY09370, UG1 EY025180, UG1 EY025181, UG1 EY025182, UG1 EY25183 and P30 EY002687. Further support for research to prevent blindness.