A new study published in the journal Frontiers in Neurology has found that Viagra (sildenafil) used for the treatment of erectile dysfunction (ED) could lead to long-term visual disturbances.
Researcher Dr. Cüneyt Karaarslan of the Dünyagöz Adana hospital in Turkey said, “There have been reports of visual disturbances seen with the use of sildenafil before but no confirmed association has been noted before.”
Dr. Karaarslan explained that Viagra has widely been used for the treatment of ED. The drug’s side effects on heart health have been reported and studied, but little is known about its side effects on vision.
The study titled, “Ocular Side Effects of Sildenafil That Persist Beyond 24 h—A Case Series,” looked at 17 male patients, who took the highest recommended dose of Viagra, reported problems such as light sensitivity and vision impairment of color. The patients were followed up from August 2017 to March 2019.
Sildenafil, which is sold under the brand name Viagra for ED treatment, was originally developed for a condition called pulmonary arterial hypertension (PAH), which means high blood pressure in the lungs. In fact, sildenafil is sold under the brand name Revatio for PAH.
The drug was found to relax the smooth muscles and dilate the blood vessels, which is why it helps with achieving and sustaining an erection.
The U.S. Food and Drug Administration (FDA) approved sildenafil for the treatment of ED in 1998. Since then, millions of men who fail to achieve and sustain an erection have been using it.
One of the common effects of Viagra is blurred vision that may last for a few hours, which is often accompanied by a headache. Sildenafil shows its effects with an hour of dosage and may last long up to three to five hours.
In the study, Dr. Karaarslan found that the patients who took a high dose of Viagra had complaints of visual disturbances, with abnormally dilated pupils that caused blurry vision and increased sensitivity to light.
They also reported visual disturbance in color vision. Most of them complained of intensely blue-colored vision. Also, some reported the inability to perceive and detect red and green colors.
The author wrote, “Of the 17 patients, nine had photophobia, 13 had disrupted color perception, nine had impaired visual acuity, three had deficiencies in stereopsis, six had disrupted contrast sensitivity, and eight had abnormally dilated pupils.”
“These men had taken the drug for the first time and took doses of around 100 mg without prescription,” wrote Dr. Karaarslan. “Even after 24 to 48 hours of taking the drug, the men showed persistent disturbance of vision.”
He further explained the effects of sildenafil usually last for up to five hours, but in these cases, the visual disturbances persisted. In addition, some patients reported other side effects such as a headache and heartburn.
Dr. Karaarslan said, “Many men use non-prescription performance-enhancing drugs to help with sexual anxiety and erectile dysfunction. For the vast majority of men, any side effects will be temporary and mild. However, I wanted to highlight that persistent eye and vision problems may be encountered for a small number of users.”
He explained that Viagra may metabolize differently in different individuals and could remain in their body for a much longer time than others, which could be one of the reasons behind the long-term visual disturbances.
Dr. Karaarslan concluded that there should be awareness related to the potential visual side effects of high Viagra dose in spite of its spontaneous effect, especially if men are taking it without a prescription. Ideally, men with ED should start with lower doses of Viagra. Dr. Karaarslan concluded, “Although these drugs, when used under the control of physicians and at the recommended doses, provide very important sexual and mental support, uncontrolled and inappropriate doses should not be used or repeated.”
