Case-control study shows reduction in new-onset GA, particularly in nondiabetic patients
STOCKHOLM — The risk of developing geographic atrophy (GA) declined significantly in patients who had a history of treatment with metformin, a case-control study involving claims data showed.
Overall, the prevalence of GA was 12% lower in patients with or without diabetes. The magnitude of reduction increased to almost 50% in patients without diabetes. Applying the findings only to patients without diabetes yielded a number needed to treat (NNT) of less than 100.
The findings add to other data showing an association between metformin use and a reduced risk of age-related macular degeneration (AMD), including GA, or dry AMD, said Dimitra Skondra, MD, PhD, of the University of Chicago, at the American Society of Retina Specialists meeting.
“We still have an unmet need for therapeutics to prevent geographic atrophy,” said Skondra. “Metformin use was associated with decreased risk of new-onset ICD coding for geographic atrophy of up to 47%. It has the potential to be repurposed to prevent GA, given how easy and accessible it is. Additional studies are needed to confirm these associations and to motivate a clinical trial.”
Following the talk, co-moderator Raj Maturi, MD, of the Midwest Eye Institute in Indianapolis, asked Skondra whether she currently uses metformin among patients with early and intermediate AMD and a high risk of GA, such as a family history of AMD.
“We don’t yet have the clinical data to say for sure that it works, only indirect evidence,” Skondra replied. “There is a strong body of evidence from preclinical data and big data. So what do I say when patients ask me what they should do? They have done genetic testing, they have a strong family history. They have noticed changes in the quality of their vision and color sensitivity.”
“I discuss what is out there and I let them decide. But I ask them to have a discussion with their family doctor first to see whether there might be some side effects or interactions with other medications. I think we need to do more work before we offer it to patients widely.”
Metformin has several desirable characteristics that make it an attractive option for the unmet therapeutic need for early intervention in GA, said Skondra. The drug is widely available and inexpensive, has an excellent side effect profile — including no risk of hypoglycemia — and an expanding off-label use for prediabetes, gestational diabetes, polycystic ovarian syndrome, and metabolic syndrome……
Read more: https://www.medpagetoday.com/meetingcoverage/asrs/111189
Source: MedPage Today-