Concerns that Eli Lilly’s popular weight-loss and diabetes treatment, Mounjaro, might exacerbate eye complications in diabetic patients appear to be misplaced. While the risk of diabetic retinopathy may increase temporarily upon starting the medication, a long-term follow-up study has confirmed that the drug actually suppresses the onset of these complications after one year.
Mounjaro (generic name tirzepatide) is a dual-hormone regulating injection that suppresses appetite. It has gained significant market traction due to weight-loss results that often surpass those of Novo Nordisk’s Wegovy (generic name semaglutide).
The "Rapid Drop" Paradox
Early reports suggested that roughly 7% of patients using these classes of drugs were being newly diagnosed with diabetic retinopathy—a condition where damaged retinal microvessels lead to vision loss or blindness.
The primary cause of retinopathy is prolonged high blood sugar. However, a "paradoxical" worsening can occur when blood sugar is lowered too rapidly. A sudden drop can temporarily decrease oxygen supply to retinal vessels or cause pressure changes that lead to vessel rupture. Because Mounjaro is so effective at slashing blood sugar levels, these short-term complications were initially a point of concern.
Large-Scale Data Flips the Narrative
A research team from Weill Cornell Medicine recently challenged these concerns, stating that Mounjaro actually lowers the long-term risk of eye disease.
The team analyzed the health records of over 174,000 diabetic and obese patients in the U.S. health system. After tracking the results for over a year, the findings were conclusive:
Only 0.49% of Mounjaro users were diagnosed with even mild diabetic retinopathy.
In contrast, the control group (patients not using Mounjaro) saw a diagnosis rate of 1.2%.
By significantly lowering the long-term risk, Mounjaro reduces the number of patients who eventually require invasive interventions like intravitreal injections or laser surgery.
Expert Opinion: No Reason to Hesitate
Lead author Dr. Szilard Kiss, a professor of ophthalmology at Weill Cornell Medicine, acknowledged the initial risks but put them into perspective.
"It is a medical fact that Mounjaro can temporarily increase the risk of diabetic retinopathy," Dr. Kiss stated. "However, this is precisely because the drug’s blood sugar improvement is so remarkable. When you consider the long-term suppression of the disease, there is no reason for patients to hesitate in using these treatments."
The results of this study were published in the latest issue of Ophthalmology, the journal of the American Academy of Ophthalmology (AAO). While Mounjaro has now been cleared by long-term data, it is important to note that similar long-term, large-scale studies for Wegovy regarding retinopathy risks are still ongoing.
