Nikhil Prasad Fact checked by:Thailand Medical News Team Jun 02, 2026 55 minutes ago
Medical News: Millions of people around the world take serotonin-norepinephrine reuptake inhibitors (SNRIs) to treat depression, anxiety disorders, and chronic pain. While these medicines are generally considered safe and effective, a new large-scale safety analysis has raised concerns that some of these commonly prescribed drugs may be linked to a range of eye-related problems that could affect vision and quality of life.
Large-scale safety analysis finds certain commonly prescribed SNRI antidepressants may be associated with blurred vision,
enlarged pupils, and other eye-related complications
Researchers from the Department of Ophthalmology at The First Affiliated Hospital of Soochow University in Suzhou, China, conducted an extensive investigation into eye-related adverse events associated with five major SNRI drugs: venlafaxine, duloxetine, desvenlafaxine, milnacipran, and levomilnacipran.
Thousands of Eye-Related Cases Examined
The researchers analyzed data from the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS), one of the world's largest drug safety databases. The study reviewed reports collected between 2004 and 2024 and identified a total of 5,860 cases involving eye-related adverse events linked to SNRI use.
Although no major safety signal was detected when eye disorders were viewed as a broad category, a closer examination revealed important differences between individual drugs. Several specific eye-related problems appeared far more frequently than expected and showed strong associations with certain SNRIs.
Blurred Vision Emerges as a Common Complaint
One of the most consistent findings across all five medications was the frequent reporting of blurred vision and visual impairment. These complaints appeared repeatedly regardless of which SNRI was being used.
Researchers believe these symptoms may stem from the way SNRIs affect the nervous system. Because these drugs increase levels of serotonin and norepinephrine, they can influence muscles and structures inside the eye that help regulate focus and pupil size.
Patients experiencing blurred vision may notice difficulty reading, focusing on nearby objects, or adjusting to changing light conditions.
Enlarged Pupils Found to Be a Major Warning Sign
A particularly striking finding involved mydriasis, a condition in which the pupils become abnormally enlarged.
Mydriasis emerged as one of the strongest safety signals for duloxetine, desvenlafaxine, and especially venlafaxine. The researchers found that venlafaxine showed some of the strongest associations with eye-related complications, including unequal pupil size, known as anisocoria, and accommodation disorders that affect the eye's ability to focus properly.
Enlarged pupils can make individuals more sensitive to light, cause glare, and potentially contribute to more serious eye complications in susceptible patients.
Differences Between Individual Drugs
The study revealed that not all SNR
Is carry the same pattern of eye-related risks. Venlafaxine showed particularly strong associations with mydriasis, anisocoria, and focusing difficulties. Duloxetine was linked not only to mydriasis but also to photopsia, commonly described as flashes of light, and eye movement disorders.
Desvenlafaxine demonstrated strong signals for abnormal eye sensations and eye movement problems.
Levomilnacipran showed fewer significant signals overall, with visual impairment standing out as the main concern. Milnacipran displayed the lowest level of significant eye-related safety signals among the drugs analyzed.
This
Medical News report highlights that the findings point toward drug-specific risk profiles rather than a single class-wide effect, suggesting that certain patients may face different eye-related risks depending on which SNRI they are prescribed.
Eye Problems May Appear Months Later
Another important discovery involved the timing of adverse events. Some eye-related complications appeared relatively quickly after treatment began. Milnacipran showed a median onset time of just 11.5 days, while desvenlafaxine averaged about 31 days.
In contrast, eye problems linked to venlafaxine and levomilnacipran often developed much later, with median onset times of 147 and 161 days respectively. Duloxetine showed a broad pattern, with some events occurring during the first week and others emerging more than a year after treatment started. These findings suggest that patients and healthcare providers should remain alert for vision changes even long after treatment has begun.
Women Reported More Eye-Related Events
The analysis also uncovered notable sex-related differences. Women accounted for the majority of reported ocular adverse events across all SNRI medications. Certain eye complications appeared more frequently in women, while some unique patterns emerged among men.
Although the reasons remain unclear, the researchers suggest that biological and hormonal differences may play a role and warrant further investigation.
Conclusion
The study provides one of the most comprehensive examinations to date of eye-related adverse events associated with SNRI antidepressants. While the overall risk remains relatively low, the findings show that specific medications may carry distinct ocular safety concerns that should not be overlooked. Blurred vision, visual impairment, enlarged pupils, and focusing difficulties emerged as the most important warning signs. The researchers stress that these results do not prove that the drugs directly cause every reported eye condition, but they do highlight patterns that deserve closer attention. Patients taking SNRIs should promptly report any vision changes, light sensitivity, eye discomfort, or unusual visual symptoms to their healthcare providers. Increased awareness and regular monitoring may help identify potential problems early and reduce the risk of long-term visual complications.
The study findings were published in the peer reviewed journal: Frontiers in Pharmacology.
https://www.frontiersin.org/journals/pharmacology/articles/10.3389/fphar.2026.1837592/full
For the latest on serotonin-norepinephrine reuptake inhibitors (SNRIs), keep on logging to Thailand
Medical News.
Read Also:
https://www.thailandmedical.news/articles/med-news
https://www.thailandmedical.news/articles/ophthalmology-(eye-diseases)
https://www.thailandmedical.news/articles/mental-health
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