Mixed findings on associations between tirzepatide and diabetic retinopathy
New-onset proliferative diabetic retinopathy occurred in 1.1% of patients on tirzepatide versus 0.5% of matched controls, but new onset of any retinopathy was less common in patients with diabetes who took tirzepatide and had no retinopathy at baseline, a retrospective study found.
Patients taking tirzepatide had significantly increased odds of early worsening of proliferative diabetic retinopathy (DR), but the drug was also associated with a reduction in new retinopathy in patients without retinal disease at baseline, a study found.
To examine whether early worsening of DR occurred after beginning tirzepatide, researchers conducted a retrospective cohort study matching 3,435 patients who had been taking tirzepatide for more than 180 days with 3,434 who had not taken the drug. Patients included in the study had a mean HbA1c level of 56.1 mmol/mol (7.28%) at baseline. Results were published July 10 by Diabetologia.
New-onset proliferative DR (grade R3M0, R3M1) occurred in 1.1% (n=33) of tirzepatide-exposed patients and 0.5% (n=17) of matched controls. Tirzepatide was significantly associated with new-onset proliferative DR in multivariate analysis after adjustment for established risk factors (odds ratio [OR], 2.15 [95% CI 1.24 to 3.74]; P<0.01). However, tirzepatide was also associated with reduced odds of new onset of retinopathy (OR, 0.73 [95% CI 0.62 to 0.86]; P<0.001) in patients without DR at baseline. The drug was not significantly associated with retinopathy progression in individuals with mild non-proliferative DR (grade R1M0 or R1M1) at baseline.
Study limitations included that data on the endpoints came from annual digital retinal photography images not synchronized with when patients began tirzepatide. This resulted in large confidence intervals for time to progression, making it difficult to determine how soon or often that patients at higher risk of progression to proliferative DR should be see an ophthalmologist. However, the increase in odds of progression of existing retinopathy cases justifies specialist ophthalmologist referral, the study authors wrote.
“Our findings, in a group of relatively well-controlled individuals with diabetes, not only reinforce the need for additional retinal photography in those already at high risk of [proliferative] DR who commence treatment with tirzepatide but also provide reassurance that [early worsening of] DR is rare in individuals with lower pre-treatment risk,” the authors wrote.