Many people with age-related macular degeneration (NAMD) lost less vision than expected during treatment delays imposed by COVID-19, the researchers say.
According to James Talks, MB BChir, an ophthalmologist consultant at the Royal Victoria Infirmary in Newcastle upon Tyne, UK, the finding suggests that doctors may be overdoing it in these patients.
“If it delays people with macular degeneration, it’s likely to get worse,” he said Medscape Medical News. “We’ve quantified it, to some extent. And you could argue it wasn’t as bad as you might have thought.”
He the study was presented at the 2021 annual meeting of the Virtual Association for Vision and Ophthalmology Research (ARVO).
Intravitreal injections with antivascular endothelial growth factor (VEGF) treatments have been shown to be potent in improving the visual acuity of people with AMD. But injections are uncomfortable and require frequent visits, which imposes a burden on both patients and the healthcare system.
Therefore, most ophthalmologists have adopted an approach to treat and expand, increasing the intervals between injections while monitoring to ensure that the patient’s vision does not deteriorate.
Deciding how much to delay is an inaccurate science. The pandemic created an accidental test of what happens when the intervals between injections extend much longer than has been tested in a clinical trial.
Doctors at the Royal Victoria Infirmary treat their patients with aflibercept (Eylea). After the first few weeks, they usually widen the gap between injections to about eight weeks, Talks said.
UK national guidelines recommended delaying treatment only in those patients with diabetic macular edema or occlusion of the retinal vein, which would have been about a quarter of all patients receiving anti-VEGF treatment at the clinic.
But many patients with DMAM also decided to delay treatment, either because they feared contracting COVID-19 or because they did not want to impose a burden on health care workers treating patients with COVID-19, Talks said. In total, 67% of the clinic’s anti-VEGF patients delayed treatment.
To see the good performance of these patients, Talks and colleagues performed a random sampling of 681 eyes on 585 patients who had received treatment between January 1, 2020 and March 23, 2020, when the UK closed.
They found that the mean number of weeks of delay was 12.7 weeks and that 8.2% of patients had not yet returned at the time of follow-up, whereas 28.5% had delayed treatment before returning. 63.3% had continued treatment according to schedule.
Patients who delayed treatment but eventually returned fell 4.9 letters, from 60.1 to 55.2. Those who were not late dropped an average of 1.5 letters, from 61.4 to 59.9. The difference was statistically significant (Pg = .001). By November, 74.6% of the eyes had returned to the five letters of basal vision.
The researchers analyzed optical coherence tomography (OCT) images of patients ’eyes to see if they could find out which ones were most likely to lose vision.
The central macular thickness of the retarded eyes increased from 311 µm to 342 µm. The majority (73%) of the eyes with delayed treatment showed evidence of intraretinal or subretinal fluid. They were evenly divided between the subretinal fluid, the intraretinal fluid, and the combination.
But there was no clear pattern that could have been used to predict which patients were most likely to lose vision, Talks said.
The best method to determine which patients might delay their treatments is to try longer intervals on a treatment regimen and extension, he said. “Suppose they came back today after an 8-week gap. If it was dry, maybe we could treat them and go back to them in ten weeks, and that would be a two-week extension. And if it was still dry, we try and return them at twelve weeks. “
Another possible lesson from the pandemic is that patients were less likely to delay treatment if they had an eye with better vision that was being treated. They were motivated to preserve the vision of that eye because they could not back away from the other eye, Talks said.
That lesson could apply in the event of another blockade, he said. “If you’re under pressure, you should give priority to those in whom you treat the best eye.”
As expected, patients with diabetic macular edema lost less vision than those with NAMD.
U.S. ophthalmologists are also trying to measure the damage the pandemic caused to their patients’ vision, said Jayanth Sridhar, MD, an associate professor of clinical ophthalmology at the Bascom Palmer Eye Institute in Miami, Florida.
Should another blockage occur, he would like to devote more effort to educating patients and primary care physicians about the key symptoms that should lead patients to seek the care of an ophthalmologist more urgently.
Better technology for mobile monitoring and screening, such as home OCTs, is important in those patients receiving anti-VEGF treatment, he said. “If we can get these things out, they will help if there are future pandemics.”
John Wells, MD, of the Palmetto Retina Center in Columbia, South Carolina, said Medscape Medical News that the clinic did everything it could to respond to patients ’fears. “In fact, we had some patients who refused to come into the office and we got out of their car and we injected them,” he said. “It’s like an auto-injection clinic.”
The talks revealed financial relationships with Alimera, Allergan, Bayer, Novartis and Roche. Wells revealed relationships with Adverum, Genentech, Roche, Alimera, Bayer, Iveric Bio, Kodiak, Neurotech and Regeneron. Sridhar revealed a relationship with Regeneron.
Annual meeting of the Association for Research in Vision and Ophthalmology (ARVO) 2021: Summary. Filed May 6, 2021.
Laird Harrison writes about science, health, and culture. His work has appeared in national magazines, newspapers, public radio and websites. He is working on a novel about alternative realities in physics. Harrison teaches writing at the Writers Grotto. Visit it at www. lairdharrison.com or follow him Twitter: @LairdH