(Reuters Health) - People with a common age-related eye disease who show up regularly for their doctor’s visits get to keep more of their sight than those who skip appointments or stretch the time between visits, a new analysis suggests.
Researchers examined data from a two-year study that compared different treatments for age-related macular degeneration (AMD), a leading cause of vision loss in the United States.
About 90% of patients stuck to a schedule of monthly visits, but the rest skipped or delayed visits for weeks or months.
At the end of the trial, the largest difference in vision sharpness was seen between the group considered “on time,” with 28 to 35 days between clinic appointments, and those who were “very late,” with over 60 days between visits.
“There was a 12.5 letter difference between people who were poorly adherent and people who stuck to their visit schedule. That translates to roughly two and a half lines on the chart most eye doctors hang in their offices!” said study coauthor Dr. Brian VanderBeek of the Perelman School of Medicine at the University of Pennsylvania in Philadelphia.
“I was pretty surprised that there was such a dramatic difference between those two groups,” VanderBeek said in a phone interview.
The magnitude of the association between visit adherence and improved vision suggests substantial effort should be made to strive for visit adherence, the researchers write in JAMA Ophthalmology.
But getting treatment for the condition can be an onerous task.
Patients are usually elderly and often require caregivers to accompany them on monthly trips to a clinic, where they receive an injection directly into the eye.
“The injections are not fun,” VanderBeek said.
“Most patients do not like the experience - unfortunately we do not have another way of giving them the medication. (And) it’s not like you come into the office for 10 minutes and then you just leave. Usually you’re there for an hour or two.”
“When you put all of those factors together it creates an environment where it’s often very difficult for patients to get the care they need as frequently as they need it.”
Dr. Shriji Patel of the Vanderbilt Eye Institute in Nashville, Tennessee, who coauthored a commentary accompanying the study, said achieving the level of visit adherence enforced during clinical trials in day-to-day practice is “nearly impossible.”
This could explain why data from electronic medical records show anti-VEGF treatments, the gold standard at present, don’t work as well at improving vision in practice as they seem to in clinical trials, he told Reuters Health.
Anti-VEGF treatments like Lucentis from Roche AG and Novartis, Avastin from Roche and Eylea from Regeneron Pharmaceuticals Inc and Bayer AG are initially administered once a month. “After that, retina specialists differ ... but the majority adopt what is known as a ‘treat-and-extend’ regimen, where they slowly increase the interval between subsequent injections,” Patel explained.
The new analysis was of high quality, Patel noted, though the fact that the trial wasn’t originally designed to determine the link between visit adherence and vision improvement makes the conclusions less reliable.
VanderBeek also commented on the variability between clinical trial results and those achieved in practice.
“In the real world outside of clinical trials, decisions for when and where to follow up to be treated are not uniform across physicians,” he said.
“There’s a lot of input from both physicians and patients into when follow up should occur, which causes a lot of variability in how frequently patients are seen.”