Is blurry eyesight a side effect of taking Wegovy (semaglutide) and what should be done if it occurs, especially in patients with a history of diabetes?

Blurry Vision with Wegovy (Semaglutide): Recognition and Management

Yes, blurry vision is a documented side effect of Wegovy (semaglutide), and patients experiencing this symptom require same-day ophthalmologic evaluation, particularly if they have diabetes or pre-existing retinal disease. 1

Immediate Action Required

Stop Wegovy immediately and arrange same-day ophthalmology assessment if the patient experiences:

• Blurry vision or visual impairment 2
• Eye pain 1
• Photophobia (light sensitivity) 1
• Blind spots or shadows in vision 1
• Any visible changes to the eyes 1

Understanding the Risk Profile

Direct Ocular Effects

Real-world data from the FDA Adverse Event Reporting System analyzing over 17 million reports demonstrates that semaglutide is significantly associated with ocular adverse events, with a reporting odds ratio of 1.25 (95% CI, 1.20-1.31). 2 The most commonly reported ocular adverse events include blurred vision, visual impairment, and diabetic retinopathy, with some occurring as early as 10 days after treatment initiation. 2

Diabetic Retinopathy Worsening

The most critical concern is rapid worsening of diabetic retinopathy in patients with pre-existing retinal disease. 1 The American Diabetes Association specifically recommends assessing retinopathy status before intensifying glucose-lowering therapies with GLP-1 receptor agonists like Wegovy, as semaglutide carries an increased risk of rapidly worsening diabetic retinopathy. 1

Pre-Treatment Evaluation Algorithm

Before prescribing Wegovy to any patient:

1. Obtain dilated fundoscopic examination for all diabetic patients and document presence and severity of any retinopathy 1
2. For patients with type 2 diabetes, perform dilated eye examination at diagnosis to establish baseline retinopathy status 1
3. Document the following high-risk features:
   • Pre-existing diabetic retinopathy of any severity 3
   • Diabetes duration ≥10 years 3
   • Age >60 years 3
   • History of uveitis or macular edema 1

Monitoring Protocol During Treatment

For High-Risk Patients

Schedule ophthalmologic follow-up within 1-3 months of initiating therapy and continue close monitoring every 3-6 months during the first year. 3 Consider slower dose titration to minimize rapid HbA1c fluctuations in high-risk patients. 3

For All Patients

Patients require regular ophthalmologic examinations throughout treatment, monitoring for specific visual symptoms including blind spots or shadows in central vision, sensitivity to light, and distorted contour and color of objects. 1

When Vision Changes Occur

If vision changes develop during treatment:

1. Arrange same-day ophthalmology referral 1
2. Document timing relative to semaglutide initiation and dose changes 1
3. Check current HbA1c and compare to baseline 1
4. Do not attribute all visual symptoms to diabetic retinopathy alone, as semaglutide itself can cause direct ocular effects 3, 2

Critical Management Decisions

Should Wegovy Be Discontinued?

Wegovy should not be discontinued solely due to retinopathy, as ongoing glycemic control remains critical. 3 However, if proliferative diabetic retinopathy is detected, patients require treatment with either panretinal photocoagulation or anti-VEGF therapy, with follow-up intervals of less than 1 month. 3

Cardiovascular Benefits vs. Ocular Risks

Do not delay Wegovy in patients who would benefit from its cardiovascular and renal protective effects solely due to retinopathy concerns. 3 In 2024, Wegovy was approved by the FDA to reduce the risk of cardiovascular death, heart attack, and stroke in adults with obesity or overweight and cardiovascular disease, with major cardiovascular events occurring in 6.5% of those treated with Wegovy compared with 8% in the placebo group. 4

Common Pitfalls to Avoid

• Do not assume blurry vision is benign or temporary – it requires ophthalmologic evaluation 1, 2
• Do not continue dose escalation without ophthalmologic clearance in high-risk patients 3
• Do not forget to optimize other risk factors, including blood pressure control, lipid management, and target HbA1c <7% while avoiding overly rapid reduction in high-risk patients 3
• Do not confuse this with phentermine-related visual effects, which have different mechanisms and management (phentermine is contraindicated in glaucoma patients) 5

Mechanism of Visual Disturbances

Gene enrichment analysis has highlighted potential links between GLP-1-related genes and ocular adverse events, though the exact mechanisms require further experimental studies. 2 The rapid glycemic improvement with semaglutide can paradoxically worsen existing retinopathy in high-risk patients. 3