Dimitra Skondra, MD, PhD: Protective Effect of Metformin in Geographic Atrophy

Metformin treatment was associated with a reduction in new-onset International Classification of Diseases (ICD) coding of geographic atrophy (GA), according to data presented at the 2024 Association for Research in Vision and Ophthalmology (ARVO) Meeting.

Recent approvals from the US Food and Drug Administration (FDA) marked first-time therapies for slowing GA progression, but without significant benefit for visual acuity, other well-tested therapies, such as metformin, may represent an alternative therapeutic for GA prevention.

In an interview with HCPLive, Dimitra Skondra, MD, PhD, an associate professor of ophthalmology and visual science and the director of the J. Terry Ernest Ocular Imaging Center at The University of Chicago, described the difficulties in controlling GA progression and the unmet need in targeting the disease before it gets to the advanced stages and vision loss.

“I think metformin fits very well, it’s almost the perfect candidate for a non-invasive strategy to target patients when they’re earlier in the disease stage,” Skondra told HCPLive. “It’s safe, affordable, and may help delay the process until they go to advantage stages of wet age-related macular degeneration (AMD) or GA in particular.”

The case-control study was performed in the Merative MarketScan Commercial and Medicare databases between 2016 and 2021. Cases were aged ≥60 years with new-onset ICD coding of GA and matched on year, age, geographic region, Charlson Comorbidity Index, and hypertension status to control without GA.

Exposure to metformin was evaluated in the year before the index visit for both cases and controls. Conditional multivariable logistic regression was used to test the association between metformin use and new-onset coding of GA and then repeated in a diabetic patient subgroup, with adjustment for relevant risk factors and exposure to other anti-diabetic medications.

Approximately 10505 cases with GA and 10502 matched controls without GA were identified for analysis, of which 27.6% and 28% were diabetic, respectively. Overall, 1149 (10.9%) cases and 1278 (12.2%) controls were exposed to metformin.

Across the full sample, metformin lowered the likelihood of new-onset ICD coding of GA by 12% (95% CI, 0.79 – 0.99). Meanwhile, for those specifically with diabetes, metformin use reduced the odds of new-onset GA coding by 11% (95% CI, 0.78 – 0.999). In those without diabetes only, metformin decreased the odds of developing new-onset coding of GA by 47% (95% CI, 0.33 – 0.83).

“It seems when you look at more specific subtypes, and you define your cohorts more homogenously, the signal becomes stronger,” Skondra told HCPLive. “That was very encouraging and we’re very excited to see a possibly non-diabetic cohort for clinical applications.”

Disclosures: Dimitra Skondra reports no relevant disclosures.

References

_{Moir J, Hyman M, Flores A, Hariprasad S, Skondra D. Metformin protects against new-onset ICD coding of geographic atrophy: findings from a national case-control study. Poster presented at the Association for Research in Vision and Ophthalmology (ARVO) 2024 Meeting, May 5–9, 2024.}