What percentage of blindness is caused by Tadalafil (Cialis)?

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Last updated: May 8, 2025View editorial policy

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From the Guidelines

Blindness caused by tadalafil is extremely rare, occurring in less than 0.01% of users. Tadalafil has been associated with a condition called non-arteritic anterior ischemic optic neuropathy (NAION), which can cause sudden vision loss, but this is an uncommon side effect, as noted in various studies, including those on phosphodiesterase type-5 inhibitors 1. The risk appears to be higher in people who already have risk factors such as heart disease, diabetes, high blood pressure, high cholesterol, being over 50 years old, or having certain pre-existing eye problems. Some key points to consider when evaluating the risk of blindness associated with tadalafil include:

  • The mechanism is thought to be related to changes in blood flow to the optic nerve, which can be affected by the medication's action on phosphodiesterase type-5.
  • If you experience any changes in vision while taking tadalafil, you should stop the medication immediately and seek medical attention.
  • It's essential to discuss your complete medical history with your doctor before starting tadalafil to assess your individual risk factors for potential side effects, including vision problems. Given the information available, including the study from the European Heart Journal 1, it's clear that while there is a potential risk, it is relatively low, and the benefits of the medication for approved conditions should be weighed against this risk on an individual basis.

From the Research

Tadalafil and Blindness

  • The exact percentage of blindness caused by tadalafil is not specified in the provided studies 2, 3, 4, 5, 6.
  • However, the studies suggest that tadalafil, a phosphodiesterase type 5 inhibitor, can cause visual disturbances and ocular complications, including nonarteritic anterior ischemic optic neuropathy (NAION) and reversible damage to the photoreceptors 2, 3, 4, 5, 6.
  • The incidence of these adverse events is considered rare, and the evidence to support a direct cause-effect relationship between tadalafil use and vision-threatening ocular events is weak 3, 4, 5.
  • Minor visual adverse effects, such as changes in color perception and increased light sensitivity, occur in 3-11% of users and are typically transient and reversible 4.

Ocular Complications Associated with Tadalafil

  • Nonarteritic anterior ischemic optic neuropathy (NAION) 3, 4, 5, 6
  • Reversible damage to the photoreceptors 2
  • Chorioretinopathy 6
  • Glaucoma 6
  • Optic atrophy 6
  • Retinal occlusion 6
  • Visual field changes 6

Recommendations

  • Patients should be warned to seek medical attention if they experience visual field or acuity loss after using tadalafil 3, 5.
  • Tadalafil should be avoided in men who have already experienced NAION in one eye 3.
  • Physicians should continue to advise patients to stop use of tadalafil and seek immediate medical attention in the event of a sudden loss of vision as a safety measure 5.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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